Primary sclerosing cholangitis (PSC) and IgG4‐related sclerosing cholangitis (IgG4‐SC) are chronic fibro‐inflammatory immune‐mediated hepatobiliary conditions that are challenging to distinguish in a clinical setting. Accurate non‐invasive biomarkers for discriminating PSC and IgG4‐SC are important to ensure a correct diagnosis, prompt therapy and adequate cancer surveillance.n = 100), IgG4‐SC (n = 23) and healthy controls .We performed nuclear magnetic resonance (NMR)‐based metabolomic profiling using serum samples collected prospectively from patients with PSC , the diagnostic AUC increased to 1.0, suggesting that the metabolome differences identified are not a result of the increased prevalence of IBD in PSC relative to IgG4‐SC patients. Serum lactate (p < .0001), glucose (p < .01) and glutamine (p < .01) metabolites were increased in IgG4‐related disease (IgG4‐RD) and IgG4‐SC individuals compared to PSC, whereas mobile choline (p < .05), 3‐hydroxybutyric acid (p < .01) and ‐CH3 lipoprotein resonances (p < .01) were decreased.Multivariate analysis of the serum metabolome discriminated PSC from IgG4‐SC with greater accuracy (AUC 0.95 [95%CI 0.90–0.98]) than IgG4 titre (AUC 0.87 [95%CI 0.79–0.94]). When inflammatory bowel disease (IBD) was excluded as a comorbid condition (IgG4‐SC Taken together, serum metabolomic profiling has the potential to be incorporated as a diagnostic criterion, independent of IgG4 titre, to improve the diagnosis of IgG4‐RD and help distinguish IgG4‐SC from PSC. AIPautoimmune pancreatitisAUCarea under curveBCRB‐cell receptorCIConfidence intervalHCHealthy controlIBDInflammatory bowel diseaseIgG4‐RDImmunoglobulin G4‐related diseaseIgG4‐SCImmunoglobulin G4‐related sclerosing cholangitisNMRNuclear magnetic resonanceOPLS‐DAOrthogonal partial least squares discriminant analysisPSCPrimary sclerosing cholangitisROCReceiver operating characteristicsIgG4serum IgG4UDCAUrsodeoxycholic acidVIPVariable importance in projection1Primary sclerosing cholangitis (PSC) and IgG4‐related sclerosing cholangitis (IgG4‐SC) are progressive fibro‐inflammatory immune‐mediated conditions associated with organ dysfunction and failure, malignancy and mortality. PSC and IgG4‐SC share commonalities such as male preponderance, clinical presentation with obstructive jaundice, cholestatic liver biochemistry and bile duct stenoses on cholangiogram.To date, the rare and heterogeneous nature of these conditions has hampered the discovery of reliable biomarkers distinguishing PSC from IgG4‐SC. Measurement of serum IgG4 (sIgG4) level is a key part of the diagnostic criteria for IgG4‐RD, however, it is limited by poor sensitivity and specificity for the diagnosis of IgG4‐SC .N‐acetylated‐glycoproteins and serum lipoprotein species are known to be associated with the acute phase response and chronic inflammation, respectively. We have previously demonstrated that decreases in serum lipoproteins along with increased glucose and valine concentrations are associated with disease severity and inflammation in patients with ulcerative colitis.Metabolomics, the measurement of all small molecular intermediates, or metabolites, in a biological sample, has emerged as a powerful method of profiling disease phenotypes.Herein, we performed the first untargeted serum NMR‐based metabolomics in a cohort of 139 participants comprised of PSC, IgG4‐SC, IgG4‐RD without hepatobiliary involvement, and healthy controls (HCs). Metabolome data were investigated using multivariate statistical techniques with the aims of distinguishing PSC from IgG4‐SC and exploring the molecular mechanisms underlying these conditions and compared to those of the control cohort to provide ‘healthy’ reference ranges.22.1n = 155). Patients with IgG4‐RD , PSC (n = 100) and HC (n = 16) were prospectively recruited between 2011 and 2018 from the outpatient clinics of Oxford University Hospitals NHS Foundation Trust, a tertiary referral centre for IgG4‐RD and PSC. Patients enrolled in this study had clinical data and serum samples collected and were then prospectively followed up. Enrolled study participants provided written informed consent. The study was approved by the Research Ethics Committee, Oxfordshire  and registered on the NIHR UK portfolio (10776). It was conducted in accordance with the study protocol and the principles of the Declaration of Helsinki (2008), and the International Conference on Harmonization (ICH) Good Clinical Practices standards.The study cohort comprised individuals who had a serum sample available which was frozen at collection and then thawed only on the day of NMR spectroscopy (2.2EC is on the Steering Committee for the British Association for the Study of the Liver (BASL), Immune‐Mediated Liver Disease (IMLD), Special Interest Group (SIG), UK PSC and UK IgG4. Patient representatives with PSC and IgG4‐SC were able to provide feedback on the study concept and design of the experiment. A lay summary of the results of this study will be made available on the Oxford NDM, PSC Support and IgG4‐RD websites.2.32.The diagnosis of IgG4‐RD was made using the HISORt criteria (2006/7) for IgG4‐related pancreatic and biliary disease,For details on clinical data, sample collection and processing, NMR spectroscopy and data preprocessing, refer to supplementary methods.2.4Multivariate orthogonal partial least squares discriminant analysis (OPLS‐DA) was performed in R software   using in‐house R scripts and the ropls package.U test was applied, comparing PSC and IgG4‐RD. Chi‐squared tests were used for categorical variables. To compare individual metabolite differences between PSC, IgG4‐RD and HC, Brown‐Forsythe and Welch ANOVA with Dunnet’s T3 post hoc comparisons was used. A multiple comparisons correction (Bonferroni) was applied throughout. Two‐tailed p < .05 were considered statistically significant. ROC, AUC, 95% confidence intervals (CI) and optimal thresholds for diagnosis were calculated using the pROC package.All univariate and ROC analysis were performed in R software and GraphPad Prism 9.0 (GraphPad Software). For clinical chemistry and baseline characteristics, the Mann Whitney 33.1n = 23), 100 patients with PSC  and 16 HC were included in the analysis. The baseline characteristics of the 139 patients are summarized in Table Serum NMR spectra from 39 patients with IgG4‐RD  and 80/100 patients with PSC. As expected, IgG4 titre discriminated between PSC and IgG4‐RD with a high area under curve (AUC) value of 0.87 . The clear clustering observed in the resulting OPLS‐DA scores plot illustrates the distinct serum metabolic profiles intrinsic to IgG4‐RD and PSC  and IgG4‐SC (n = 23) was identified by OPLS‐DA  of >100 serum metabolites, simultaneously quantified by C Figure . ExternaC Figure . The posC Figure  indicateA Figure . When IgA Figure , the accA Figure  and the A Figure  and was n = 80 PSC, n = 38 IgG4). Classification using the serum metabolomic data reduces the proportion of IgG4 individuals incorrectly identified as ‘PSC’ by antibody titre from 6 (Table S2) to 4 (Table S3). The proportion of PSC individuals incorrectly identified as IgG4 by antibody titre was also reduced, from 14 (Table S2) to 8 (Table S3). When only IgG4‐SC patients were classified against PSC patients with IgG4 titre, the sensitivity was similar to antibody titre (97.3% compared to 97.1%); indeed, the same number of IgG4‐SC patients were correctly classified . Because of the improvement in correctly classifying PSC patients with high IgG4 titres  and IgG4‐RD (n = 35) remained significant when patients with IBD were removed , whereas only 10% of IgG4‐SC had IBD (indeterminate colitis). Given this discrepancy, it is important to confirm that the metabolites which discriminate between IgG4‐SC and PSC are not confounded by the IBD prevalence. To account for this, new OPLS‐DA models were generated, excluding all patients with IBD co‐morbidity. There was a clear separation in the serum metabolic profiles of PSC , age, disease duration and sex‐matched subset (n = 39) were selected. Apart from excluding all PSC patients outside the age range of the IgG4 cohort, the selection of the age‐matched PSC subset was random. The serum metabolomic OPLS‐DA model remained highly discriminatory  affords a discriminatory accuracy of 82%  is challenging.To date, only two studies have investigated the metabolome in patients with PSC and there are no previous studies which have used NMR metabolomics methods. While serum metabolomics of portal blood by mass spectrometry showed altered composition compared to cirrhosis and HCs,Certain key metabolites discriminating IgG4‐RD from PSC were similar to those discriminating IgG4‐RD from HC individuals. For example, serum lactate was found to be elevated in those with IgG4‐RD compared to PSC, where patients with PSC had similar serum lactate levels compared to HC individuals. While no studies have previously investigated serum metabolic differences between PSC and IgG4‐RD, the serum metabolic profile of PSC has been described previously in comparison to patients with cirrhosis and HCs3 lipoprotein were observed in those with higher disease activity according to both endoscopic and histological scores.3 lipoprotein observed in this study.More broadly, the key metabolites distinguishing IgG4‐RD from PSC may represent an increased systemic inflammatory phenotype in those with IgG4‐RD, including IgG4‐SC. When previously comparing patients with ulcerative colitis with high and low disease activity, increased blood glucose and lactate and decreased ‐CHIn this study, the levels of 3‐hydroxybutyric acid were reduced in patients with IgG4‐RD, compared to patients with PSC and HC. Given that BHB may mediate the resolution of inflammation by inhibiting NLRP3 inflammasome activity,Alongside inflammation, the serum metabolic signature of IgG‐RD (compared to PSC) is reminiscent of previous comparisons between antibody and non‐antibody‐mediated chronic inflammatory diseases. We previously compared the blood metabolome of patients with antibody‐mediated neuromyelitis optica spectrum disorder and relapsing‐remitting multiple sclerosis, which present with similar symptoms and clinical signs.The faecal microbiome and metabolome have been compared between IgG4‐SC and PSC.A limitation of our study was the relatively small sample size of patients with IgG4‐SC. IgG4‐SC is a rare condition and for which Oxford is a tertiary referral centre, although it should be noted that, despite this limitation, model performance was determined on independent test data in all cases. While this study is the first to provide proof‐of‐concept that serum metabolomics, in particular relative serum levels of 3‐hydroxybutyric acid, lactate, glutamine and mobile choline, can be used to diagnose IgG4‐SC from PSC, this should be reproduced in a future study. In addition, future work will determine whether these biochemical changes are detectable in the earliest stages of disease, in a prospective cohort of patients. Additionally, although our data corroborate previous findings that suggest a stronger systemic inflammatory metabolic signature associated with IgG4‐RD compared to PSC, functional studies are warranted to investigate the underlying mechanisms. Importantly, however, we show that the serum metabolic signature of IgG4‐RD can be detected from PSC independent of IBD comorbidity, which is much more prevalent in patients with PSC and has been shown to exhibit a strong metabolic signature compared to HCs.In summary, we show for the first time that blood‐based NMR metabolomics can be used to distinguish IgG4‐SC from PSC, independently of age, sex, medication and comorbid IBD. Accuracy and specificity were improved compared to optimal stratification based on serum IgG4 titre. Future investigation of the disease‐specific metabolite alterations may lead to further insights into the underlying pathophysiology of these conditions and the incorporation of specific serum biomarker panels into clinical practice.EAS, ELC, DERS, DCA, FP, RP, KDL, MO, JB, KL and AB declare no conflicts of interest. MP is a shareholder in Perspectum, a University of Oxford spin‐out company. AG was employed by UCB Celltech during the preparation of this manuscript and is now an employee of Glaxo Smith Kline (GSK).The study was approved by the Research Ethics Committee, Oxfordshire (ref:10/H0604/51) and (ref:16/YH/0247) and (ref:18/SC/0367) and registered on the NIHR UK portfolio (10776). It was conducted in accordance with the study protocol and the principles of the Declaration of Helsinki (2008), and the International Conference on Harmonization (ICH) Good Clinical Practices standards.Enrolled study participants provided written informed consent.Data S1Click here for additional data file.


The Split Hopkinson Pressure Bar (SHPB) test device is an important tool to study the dynamic characteristics of concrete materials. Inertial effect is one of the main factors that cause inaccurate results in SHPB tests of concrete materials. To solve this problem, Large-diameter SHPB tests on concrete and mortar were performed. A dynamic increase factor (DIF) model considering strain rate effect and inertia effect was established. This model provides a scientific reference for studying the dynamic mechanical properties of concrete materials. The experimental results indicate that the strain rate effect of concrete is more sensitive than that of mortar, but the inertia effect of mortar is more sensitive than that of concrete. Under the same strain rate, the energy utilization rate, average fragment size, and impact potentiality of mortar are higher than concrete. Concrete materials, the largest and most widely used engineering building materials, are affected by static loads and high strain rate dynamic loads such as earthquakes, impacts, and explosions. As a heterogeneous, anisotropic, and strain rate-sensitive multiphase composite, concrete will show more complex dynamic mechanical characteristics under dynamic load than under static load, which has been one of the hot topics in recent years. Split Hopkinson Pressure Bar (SHPB) experimental technology is the most commonly used test method for the dynamic performance of concrete ,4,5,6,7.−1 range. Ngo et al. [The dynamic increase factor (DIF), defined as the ratio of dynamic-to-static strength, is conventionally considered a material property ,16. A bio et al.  establiso et al.  adopted o et al.  used a p−1. Flores-Johnson et al. [With the progress of technology and the deepening of research, some scholars found that under high strain rate ,24, the n et al.  believedn et al.  considern et al.  expressen et al. ,34. Hao n et al. ,36 propon et al.  presenten et al.  used a pn et al.  establisn et al. ,40 descrInertia effect is an important factor causing the inaccuracy of SHPB test results of concrete materials. In order to explore the influence of the inertia effect on the strength of concrete materials under the dynamic load, SHPB tests of concrete and mortar were carried out in this paper. A DIF model considering strain rate effect and inertia effect was established. The dynamic mechanical response characteristics of mortar and concrete were compared and analyzed, which provides a theoretical basis and scientific support for seismic design and safety evaluation of concrete engineering.Some typical empirical formulas for DIF have been developed based on the SHPB test of mortar and concrete specimens. The formulae were either based on power-law variation or followed the logarithmic trends . One of Tedesco and Ross  conducteThrough explosion resistance tests of the ultra-high-strength concrete panel, Ngo et al.  also belGuo et al.  viewed t−1 and gave the following equations:Because the linear function cannot accurately describe the relationship between the DIF and the logarithmic strain rate under high a strain rate, some scholars used quadratic or cubic equations to describe it. Grote et al.  tested tLi et al.  conducteKatayama et al.  believedHao et al. ,36 regarUnder a high strain rate, the inertia effect cannot be eliminated , and it Under the high strain rate, the particles in the specimen will obtain axial acceleration, i.e., axial inertial force. In addition, lateral inertial force is also generated due to the influence of Poisson’s ratio. The macroscopic resistance of concrete must balance the actual failure force, axial inertia force, and lateral inertia force , as showBased on the previous research results, we propose a DIF model for high strain rate, as reflected in the following formula:Ordinary Portland cement (OPC) and potable laboratory tap water were used for the experiments. Conventional crushed stone with particle sizes between 8 and 12 mm and natural river sand with particle sizes between 0.25 and 0.5 mm were employed as coarse and fine aggregates, respectively. The concrete was mixed at the proportion of 0.52:1:1.67:2.47 (water/cement/sand/aggregate) and subsequently set standing for 24 h. The mold of the specimen was removed, and the specimen was placed in a constant temperature (20 °C) and humidity (95%) curing box for 28 days. The specimens were drilled and polished to smooth the end face after curing. The mortar specimens have the same composition and preparation as the cement paste in the concrete. The diameter and height of the mortar and concrete specimens used for the SHPB test were 71 × 71 mm, respectively, as shown in −5 and 1.12 × 10−5/s, respectively, and their standard deviations were 4.71 × 10−8 and 2.16 × 10−7, respectively. The stress–strain curves of mortar and concrete specimens, whose stress peak value is close to the average value, are shown in A quasi-static test was conducted before the dynamic load test. An RMT-150B multi-functional full-automatic rigid rock servo testing machine was used for the static load test. The specimen radius and height were 50 and 100 mm, respectively. There were 3 test specimens of mortar and concrete, respectively. The average peak stresses of mortar and concrete specimens were 53.06 and 31.61 MPa, respectively, and their standard deviations were 2.31 and 1.91 MPa, respectively. In order to analyze the dynamic response characteristics of the two kinds of materials, the strain rates of mortar and concrete were extracted in the test. The average strain rates of mortar and concrete specimens were 1.03 × 10−5 and 1.12 × 10−5/s, respectively.From Split Hopkinson Pressure Bar (SHPB) test technology is the most important and reliable test method to study the mechanical properties of materials under a high strain rate. The basic working principle of the SHPB test device  is that To obtain accurate and reliable data, a tapered incident bar with a diameter of 74 mm was used in the SHPB system as shown in There is severe waveform dispersion in the large diameter SHPB test. To prolong the rise time of the incident wave and filter its high-frequency oscillation, a pulse shaper was fixed on the end face of the incident bar in contact with the bullet ,43. The The SHPB test was carried out with 2 mm thick brass shaper and rubber shaper. The test results show that the shaping effect of rubber shaper is better. In order to obtain a better shaping effect, SHPB tests were carried out on rubber shapers with thicknesses of 1, 2, and 3 mm, respectively. The impact air pressure was 0.3 MPa, and the waveform test with no specimen is shown in The striker bar can obtain different initial velocities by different impact air pressures. The selected five groups of impact pressures were 0.25, 0.3, 0.4, 0.5, and 0.6 MPa. When the impact air pressure is 0.25 MPa, a 1 mm thickness rubber shaper was selected because the current signal cannot be collected by a 2 mm thickness rubber shaper. A 2 mm thick rubber shaper was used in other cases. Each group was subjected to three impact tests. The data with a large error were removed. Then, a typical stress–strain curve was selected from each group to plot, as shown in Both graphs have the same scale on the x and y axes for comparison in When comparing the impact pressure of 0.25 and 0.30 MPa in According to the analysis in In Next, the inertia effect was considered. SHPB test data were fitted by Equation (12). The abscissa was set as In When compared with Equation (16), the fitting degree is improved. It indicates that Equation (12) is feasible to fit the DIF of mortar and concrete under a high strain rate. When comparing the The energy utilization was studied to compare the effect of strain rate on the energy utilization of mortar and concrete in large-diameter SHPB tests. The energy calculation formula of stress waves is:The calculation formula of energy utilization The fracture morphology is an important aspect of evaluating the impact potentiality of concrete materials ,46. The After impact, the broken specimens were collected, classified, and screened individually. First, the classifying screens were stacked from high to low according to the pore size. Then, the broken specimens were placed on the sieve with the largest mesh size on the uppermost layer, so that the specimens with different fragmentation degrees could be separated according to size. After screening, the fragmentation on each sieve was placed on the electronic scale for weighing, and the measurement results were recorded one by one. The screened fragmentations of mortar and concrete are shown in i, in mm, and To quantify the fragmentation degree of the specimen, the average fragment size of the broken specimen was adopted. The calculation formula is as follows:The median values of the average size of the fragmentation on each classifying screen were taken according to the sieve diameter, which are 1, 3.5, 7.5, 15, 30, and 55.5 mm. The relationship between the average fragment size of mortar and concrete and strain rate is shown in In Under high strain load, axial acceleration will be obtained by the grains in the specimen. The lateral acceleration will be obtained due to the Poisson effect. In the study of inertial effect, the lateral inertial force is often considered, while the axial inertial force is often ignored. Although the axial acceleration is consistent with the bearing capacity direction of the specimen, it is caused by the uneven stress of the sample. It is closely related to the slope of the rising edge of the loading waveform, and independent from the constant strain rate of the specimen. The axial acceleration is not a part of the real strength of the specimen. Therefore, the axial inertial force should also be taken into account in the study of inertial effect. The lateral strain or dynamic Poisson’s ratio should be taken as the monitored object during the SHPB test.The inertial effect was studied by theoretical analysis or numerical simulation, but the data extraction of strain acceleration was often ignored. In the SHPB test, it was found that the rising edge of the incident wave can be changed by rubber shapers with different thicknesses, and the inertia effect can be changed accordingly. Therefore, the control variable method can be used in the indoor test, that is, the strain rate and strain acceleration can be controlled respectively to study the inertial effect. The test can be repeated in the laboratory. One of the highlights of this paper is in establishing a DIF model considering inertial effect by considering strain rate and strain acceleration. In the future research, digital image correlation (DIC), CT scanning, and other technologies could be used to retrieve the strain, crack, and damage of the specimen under inertial effect ,48. It i(1)The macroscopic resistance of concrete material is composed of the actual failure force, axial inertia force, and lateral inertia force. The dynamic growth factor (DIF) model was established. The DIF model comprehensively considers the influence of strain rate on the actual dynamic strength of concrete materials and the influence of strain acceleration on inertial effect.(2)With the increase of bullet impact velocity, the influence of inertia effect becomes greater and greater. The strain rate effect of concrete is more sensitive than that of mortar, but the inertia effect of mortar is more sensitive than that of concrete.(3)With the increase of strain rate, the energy utilization of mortar and concrete increases, while the average fragment size decreases. Under the same strain rate, the energy utilization rate, average fragment size, and impact potentiality of mortar are higher than that of concrete.In this paper, the large-diameter SHPB tests on concrete and mortar were performed, the inertia effect was studied. The conclusions are as follows:


Manufacturers of building materials strive to optimize the three basic concrete properties—strength, durability, and shrinkage deformation, of which the focus is generally on the durability in the structure when designing and monitoring the poured concrete. Studying concretes’ structural performance and the change in their characteristics over time enables the solution of many important issues associated with the design of reliable, durable, and cost-effective buildings and structures. This article presents studies aimed at improving the physical, technical, and operational characteristics of cement concrete and reducing cement consumption in heavy concretes through the use of complex modifiers and volumetric fiber reinforcement. Four concrete compositions of widely recognized grades were developed, of which samples were molded and tested for compressive and flexural strength, frost resistance, volumetric water absorption, and density. Test results confirmed the possibility of binder (cement) economy up to 18% and increasing frost resistance up to W300 when using microsilica, reduction in volumetric water absorption of up to 40% when using both microsilica and hyperplasticizer, and increasing flexural strength by over 30% when using polymer fiber. The developed compositions passed the industrial tests, and were successfully introduced in the production process of the operating reinforced concrete products’ manufacturer. From d cement . Moreoved cement ,7. In prd cement , used bod cement . Complexd cement ,10. ThesEffective heavy concretes of various functional purposes with improved building and operating properties are produced using multicomponent compositions . The cre2 crystals—which is important for the manufacture of dense and durable concrete [Active mineral additives significantly affect the basic physical and technical properties of concrete, giving it improved characteristics contributing to more efficient use of chemical energy from clinker by creating additional centers of crystallization. The number of stable hydrosilicates increases due to the reduction in the most unstable component of cement stone—Ca(OH)concrete . Analysiconcrete . The surconcrete . To obtaconcrete .One of the promising ways to improve the physical, technical, and operational characteristics of concrete is the introduction of polymeric fiber ,20. The To improve the technological properties of concrete mixtures by reducing their water content, improving their workability, and increasing their homogeneity and resistance to stratification, by using a complex modifier consisting of a hyperplasticizer based on polycarboxylate ester and ultradispersed active silica;To reduce the shrinkage deformations of concrete in the early stage of curing and increase the flexural strength of cement concrete through the use of volumetric fiber reinforcement with low-modulus polypropylene fiber, in order to improve the crack resistance and quality of products.Analysis of the aforementioned literature and the experience of the authors of this article—accumulated over several years of inspection work at the plants for the production of reinforced concrete products, along with systematic observations of the products during operation—show that it is very important not only to obtain concrete with highly desirable characteristics, but also to maintain those characteristics during the period of operation . AccordiThe purpose of this study was to improve the physical–technical and operational characteristics of cement concrete and reduce cement consumption of mainstream grades of heavy concrete by using complex modifiers and volumetric fiber reinforcement. This goal was achieved by using complex multicomponent compositions and obtaining high-quality concretes of different functional purposes with improved building and operational properties.2) that bind hydrolyzed lime to additional amounts of strong cementitious calcium hydrosilicates. In parallel, by creating additional crystallization centers, the issue of increasing the durability of concrete was addressed.The main technical task of this study was to reduce the proportion of cement in the composition of concrete. This necessity is dictated not only by the reduction in energy intensity in the production of Portland cement and the reduced consumption of fuel and electricity in the extraction, processing, and handling of raw materials, but also by the most pressing issue—significant carbon dioxide emissions during the firing of carbonate raw materials. This task was solved based on the theory of creating additional crystallization centers by using reactive pozzolanic additives  ratio and increase early and final strength indicators of concrete, increasing frost resistance and reducing the volumetric water absorption index of concrete while maintaining a given flowability, according to the basic law of concrete strength , throughThe task of enhancing the deformation properties and cracking resistance of concrete by using dispersed polypropylene fiber reinforcement was the final task of this study. Here, of particular interest was the dependence of the effect of fiber on the compressive strength and flexural strength of popular grades of heavy concrete with different binder consumption and water–cement ratios.Selection of compositions of modified heavy concrete of popular grades, as described in ;Determination of the basic strength characteristics  at the design age of 28 days;Determination of basic performance characteristics ;Comparison and analysis of test results of modified heavy concrete of mainstream grades.This study used both theoretical and empirical research methods. Theoretical research aimed to calculate the compositions of modified heavy concrete using the equation of absolute volumes and compare the results with existing compositions of heavy concrete of popular grades, determining the direction of the work, focusing on cement saving. Empirical studies were aimed at experimental confirmation of theoretically developed compositions. Furthermore, studies of physicomechanical and operational properties of the obtained modified concrete of popular grades were carried out. The studies were carried out in 4 stages, each of which was aimed at solving a specific task:This study used local raw materials. Portland cement CEM I 52.5 N manufactured by Heidelberg Cement  in Kazakhstan was used as a binder for the studied concrete mixtures. Several tests were carried out to confirm the compliance of the chosen binder with the regulations and requirements of . The metThus, the investigated binder showed a grinding fineness of 97.4%. Its normal density was 26.3%. The beginning of the setting was in 2 h 11 min, while the end of the setting was in 4 h 10 min from the moment of mixing. The values obtained were compliant with the standard. In determining the strength characteristics, the binder under study showed a bending strength of 6.1 MPa at the age of 28 days, in compression at 53.7 MPa. The obtained parameters corresponded to the standard.Sand from the manufacturer Giyada LLP , meeting the standard of , was useCrushed stones of 5–10 mm and 10–20 mm fractions produced by Baltabay LLP , with known physical and technical characteristics, were used in the coarse aggregate. This aggregate meets the requirements of , which dCondensed compacted microsilica CCM-85 manufactured by Tau-Ken Temir LLP  was used as a reactive pozzolanic additive, as described by .A chemical additive based on polycarboxylate esters of the 2nd generation AR Premium described by , produceLow-modulus polypropylene fiber of different lengths from Fibro-Lux LLC  was used for volumetric reinforcement in the studies, as described by , with thThe structure of further studies was to compare the indicators of physical–technical and performance characteristics of the modified concrete of popular grades, obtained by mathematical calculation using the equation of absolute volumes, and experimentally confirmed by laboratory mixes and studies of physical–technical and performance characteristics at the design age of 28 days. All studies and tests were conducted following interstate standards ,35,36,37Formulation of technical specifications which, in addition to the conventional requirements for concrete strength and workability of the concrete mix, must contain the minimum allowable value of its ultimate extensibility, based on the conditions of formation and, therefore, the expected or measured value of the possible deformations;Selection of raw materials and obtaining the necessary data characterizing their properties, including the water consumption of aggregates;3;Calculation of the concrete mix composition to determine the consumption of key components in kg per 1 mExperimental verification of the obtained composition and its adjustment (if necessary).The calculation involved four steps:bR was determined according to its dependence on the cement activity cR and the W/C ratiok and n are coefficients depending on the type of concrete and the quality of aggregates, respectively. For heavy concrete, n = 1.5; when using crushed stone, k = 3.5; for gravel, k = 4. This equation is valid for calculating the strength of densely placed concrete, cured under normal temperature and humidity conditions and tested by the standard method at the age of 28 days.The concrete compressive strength 3) was determined using Equations (2) and (3). The sum of the consumption of components is numerically equal to the average density of the concrete mixture, expressed in kg/m3. The calculation of the composition was based on solving a system of equations for fine-grained (Equation (4)) or heavy (Equation (5)) concrete, which include mathematical expressions that are already known and widely used in practice, such as the basic law of concrete strength, the equation of absolute volumes, and the separation factor of aggregate grains, which together can provide the relationship of consumption and the properties of the main components with the concrete strength and workability of the concrete mixture.Next, the consumption of coarse and fine aggregates (kg/mRb is the given concrete strength (MPa);h.CSV is the hollowness of crushed stone in bulk condition;pk is the coefficient of aggregate grain separation;bd.CSp is the bulk density of crushed stone;ρnd.CS is the natural density of crushed stone; Rc is the cement activity (MPa); A is the coefficient counting the quality of aggregates; C, W, S, CS, and F are the consumption of cement, water, sand, crushed stone, and fiber, respectively, per 1 m3 of concrete (kg) (fiber consumption is determined by indicators of workability by test batches);ρC, ρS, and ρCS are the grain density of cement, sand, and crushed stone, respectively (kg/m3);r is the ratio of sand and crushed stone consumption, which is assigned based on the grain composition of aggregates .The concrete compositions were then experimentally validated during laboratory batching, after which control samples of concrete were made and tested for the corresponding characteristics.As part of the compression and tensile tests, specimens were molded in the forms 2FK 100 and FP 100, according to the standard in , from thThe flexural strength of concrete was calculated with an accuracy of 0.01 MPa using Equation (6):F is the breaking load (N);a, b, and l are the width and height of the cross-section of the prism beam, and the distance between the supports, respectively, in the flexural test of samples (mm);δ is the scaling factor for converting the strength of concrete to the strength of concrete in samples of basic size and shape; WK is the correction factor for cellular concrete, taking into account the moisture content of samples during the test .After obtaining data on the compressive strength and calculations of the flexural strength of samples, the dependence of the influence of modifiers and volumetric fiber reinforcement on the flexural strength was determined.The test to determine the frost resistance was carried out via the second accelerated method described in ; the samAfter obtaining data on frost resistance, the dependence of the effect of modifiers and volumetric fiber reinforcement on the concrete frost resistance was defined.Tests to determine water absorption in concrete were conducted as described in , where csM is the mass of the water-saturated sample (g), and dM is the mass of the dry sample (g).The water absorption of each concrete sample WM (% by mass) was calculated with an uncertainty of up to 0.1%, using Equation (7):After obtaining the water absorption data , the dephttps://docs.cntd.ru/document/1200115733 (accessed on 26 February 2022) [Tests to determine the average density of concrete were conducted according to Russian State Standard GOST 10181–2014—Concrete Mixtures; methods of testing are available online at ry 2022) —where thρW (kg/m3) of concrete of each sample in the series was calculated with an error of up to 1 kg/m3 using Equation (8):m is the mass of the sample (kg), and V is the volume of the sample (m3). The average density of concrete was calculated as the arithmetic mean value of the test results of all series samples.The average density After obtaining the average density data , the effThe summary in The diagram shows that the use of modifiers allows cement consumption to be reduced while maintaining the workability of the mixture. Thus, for compositions No. 2 and No. 3, cement consumption was reduced by 14.1%, 17.1%, 19.5%, and 15.4% for concretes B25, B30, B35, and B40, respectively, while for composition No. 4, cement consumption was reduced by 12.8%, 15.9%, 18.4%, and 14.3%, respectively.The use of a polycarboxylate-ester-based hyperplasticizer reduced the W/C ratio of the compositions , therebyThe next stage of the study was laboratory tests of the selected compositions to determine their physical, technical, and operational properties .According to In 2 microsilica).The test results of the modified concrete in The strength results show that the obtained characteristics correspond to the normative values. Thus, concretes with modifying additives and volumetric fiber reinforcement show more than 30% increase in flexural strength, which is a highly significant indicator, as the improvement of deformation properties and cracking resistance of concrete by using dispersed reinforcement with polypropylene fiber was the ultimate task of this study.Comparing the obtained results with the achievements of previous studies ,39,40, t3), with better performance in terms of density, frost resistance, and volumetric water absorption, which indicate the best operating characteristics. Thus, when producing concrete sleepers with B40 graded concrete, the application of concrete mix modified with microsilica as 10% of the binder allows savings of up to 70 kg of cement per 1 m3, i.e., to reduce the consumption of expensive cement CEM I 52.5 N per 1 m3 from 455 kg to 385 kg, while maintaining all strength characteristics as specified in Russian State Standard GOST 10181–2014—Concrete Mixtures; methods of testing available online: https://docs.cntd.ru/document/1200115733 (accessed on 26 February 2022) [Based on numerous laboratory and industrial tests, it can be concluded that the use of modified concretes is justified both economically and scientifically. Unlike ordinary compositions of concrete, modified concretes allow significant savings of cement (up to 100 kg per 1 mry 2022) . Application of hyperplasticizers based on polycarboxylates is justified by several positive effects at once, such as water reduction—i.e., reduction in W/C ratio—and correspondingly increasing strength characteristics according to the basic law of concrete strength, improving the physical properties of concrete, increasing density, and reducing permeability, which follows from indicators of volumetric water absorption, while also improving the surface quality of products.One of the main strength indicators of concrete and a characteristic sought in implementing these studies is the flexural strength, as the main purpose of introducing fibers is to improve the characteristics of concrete under flexural loads. Thus, according to the study results, it can be concluded that the use of low-modulus polypropylene fibers in optimal quantities is justified in terms of improving the weakest characteristic of concrete—flexural strength .From the above conclusions, the use of modifiers and dispersal reinforcement can be recommended to reduce the cost and improve the deformation and operational properties of heavy concrete.Volumetric fiber reinforcement improves the physical–technical and deformation characteristics of existing reinforced concrete mixes, in particular increasing the flexural strength by over 30%. Volumetric fiber reinforcement with low-modular polypropylene fiber of concrete mixtures can be recommended to produce reinforced concrete products.The effect of using low-modulus plastic fiber in the frames of high-rise buildings is that it increases the flexural strength which, consequently, reduces the consumption of steel reinforcement and the cross-section of concrete partitions. Accordingly, all of these measures reduce the load on the foundation of a high-rise building.After obtaining positive results from laboratory tests, production testing of the developed compositions was carried out at the plant to manufacture reinforced concrete Firma-BENT LLP . After confirming the effectiveness of the compositions and real savings of binder in production conditions, the reinforced concrete plant included the developed compositions of concrete in its technological maps. These compositions are recommended for use in their working program to produce reinforced concrete products.


A microcapsule-type visualization sensor for concrete structural damage indication is proposed in this article. Crystal violet lactone, as damage indicator, was microencapsulated within poly(methyl methacrylate) to synthesize the sensor. The successful encapsulation was confirmed by Fourier transform infrared spectrometry. Microcapsules of different diameters and size distributions were obtained by varied stirring speeds. The fabricated microcapsules were embedded into a polymer coating to accomplish the damage indication. When cracks propagated in the coating, the crystal violet lactone in leuco form was released from the ruptured microcapsules. Due to reacting with silicon dioxide in concrete, the released crystal violet lactone turned blue and highlighted the damaged area. It was verified that the visualization performance of the sensor showed good durability in both dry and wet conditions. The proposed microcapsule-type visualization sensor has advantages of easy fabrication, high indication stability, and no special equipment requirements, which will reduce the complexity of concrete structural health monitoring significantly. A visual microcapsule sensor for concrete damage detection by color variation without the requirement for additional activators. Structural health monitoring (SHM) technologies to monitor damage are applied extensively throughout civil engineering.2,3 Since micro-cracks are hardly visible to the naked eye, specialized instruments such as optic fiber sensors,4,5 piezoelectric sensors6–9 and data processing equipment are required for traditional SHM technology.All cementitious materials, especially concrete, are susceptible to forming micro-cracks, which eventually lead to structure failure.10–14 Dye-filled hollow glass fiber15–17 was used to indicate mechanic damages for polymers, but it cannot be applied to the surfaces of complex structures because of its slender shape. The microcapsule-based visualization sensor solves these problems better.18–25 Microcapsules can be easily embedded in a polymer film because of its micro-scale. And varied formation methods make it suitable for a variety of surfaces. Recently, a microcapsule-type fluorescence probe system had been proposed for damage indication of cementitious materials.23 However, indicating cracks using fluorescence is ineffective because microcapsules by themselves are fluorescent, which will seriously interfere with crack detection. Because fluorescence cannot be captured by the naked eye in daylight, specific wavelengths of light were required for fluorescence observation.Novel material-based smart sensors provide new approaches to overcome these problems. A series of visual damage strategies based on visualization materials had been developed for damage indication.To solve these problems, a microcapsule-based damage indication strategy for concrete structures was proposed in this study. For damage indication, crystal violet lactone (CVL) containing microcapsules were applied to the surface of concrete block. As shown in In this paper, microcapsules for damage indication of concrete structure were fabricated by solvent evaporation. The morphology and successful encapsulation were confirmed by scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) spectrometer, respectively. The relationship between microcapsule diameter and the stirring speed was investigated by a laser particle size analyzer. Finally, the microcapsules were coated on a concrete block to test the damage indication performance and indication durability.2.2.1.CVL , poly(methyl methacrylate) , dichloromethane , phenyl acetate , polyvinyl alcohol .2.2.The surface morphology of microcapsules was characterized by scanning electron microscopy . The successful encapsulation of microcapsules was confirmed by Fourier transform infrared spectroscopy . The effect of stirring speed on size distribution and main diameter was investigated by a laser particle size analyzer . The drying microcapsules were obtained by a vacuum drying oven . A magnetic stirrer was used to form the microcapsules .2.3.3.3.1.−1 is assigned to the C PBM data was replaced with SVG by xgml2pxml:<glyph-data id="z.dbd" format="PBM" resolution="300" x-size="8" y-size="10" xml:space="preserve">00000000000000000000000000000000111111110000000011111111000000000000000000000000</glyph-data><svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="13.200000pt" height="16.000000pt" viewBox="0 0 13.200000 16.000000" preserveAspectRatio="xMidYMid meet"><metadata>Created by potrace 1.16, written by Peter Selinger 2001-2019</metadata><g transform="translate scale" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z"/></g></svg>O stretching vibration in CVL,26,27 which verified the successful encapsulation of microcapsules. During the grinding process of microcapsules, CVL reacts with hydroxyl groups on silicon dioxide in the agate mortar as −1 because of the opening of the lactone ring.27 In the spectra of intact microcapsules, a weak peak also appears at 1584 cm−1, because during fabrication, trace amounts of phenyl acetate was dissolved in water and hydrolyzed to acetic acid and phenol. And the lactone ring of CVL can be opened by weak acid or proton donor,28,29 thus trace amounts of CVL with already opened lactone ring generates. During preparation of the pellet, few microcapsules are ruptured by pressure, leading to the weak peak at 1584 cm−1 in the spectra of intact microcapsules. But this slight color changing cannot be captured by the naked eye. The color changing after colorless CVL reacts with pure silicon dioxide is shown in 29The FT-IR spectra of CVL, intact microcapsules and ruptured microcapsules are shown in The SEM images of the dry microcapsules are shown in 3.2.The effect of stirring speed on size distribution and main diameter is shown in 3.3.As shown in 3.4.The durability of the coating in wet and dry environment is evaluated by the dry and wet cycle as shown in 4.In this paper, the CVL containing microcapsule-type visualization sensor was successfully encapsulated by solvent evaporation. After confirmation of the successful encapsulation, the potential application and damage indication performance on concrete structure of the sensor were demonstrated. The visualization performance of the sensor showed good stability in the durability testing experiment. In addition, the proposed microcapsule-type visualization sensor has advantages of easy fabrication, high indication durability, and none special equipment requiring, which will reduce the costing in concrete structure health monitoring significantly.The authors declare no competing financial interest.


All the students completed the Program for International Student Assessment (PISA 2008) reading tests, and their principals completed the Leading and Teaching in Schools Survey Scale online which the variables of SL, TTO, and TC were evaluated. In addition, the “many to many” step was employed to match principals’ data with the students’ data by STATA analysis. The results indicated that: (1) there were direct and indirect effects of SL on student RL in the mediation model; (2) the serial mediation of TTO and TC was significant between SL and RL. This finding implies that enhancing TTO and TC in rural schools will help improve student’s RL.This study aimed to understand how teacher trust in others (TTO) and teacher commitment (TC) co-mediate the path from school leadership (SL) to students’ reading literacy (RL). Altogether 1,223 Grade 8 students (female =647; male = 576,  Teacher emotion is one of the important keys to the improvement of student achievement in schools. According to the Ontario Leadership Framework OLF; , teacherSchool leadership can mobilize and work with others to achieve common goals and has two core functions: setting direction and influencing others . The relThe second direction was examining the indirect effect between SL and student reading achievement. Trust is necessary for teachers to actively and continuously participate in school improvement . TeacherAccordingly, some studies have explored the mediating role of TTO in the relationship between SL and student achievement. For instance, As one of the key variables in the “emotions path” proposed by the Ontario Leadership Framework , TC has A recent study on Chinese schools found that the “emotions path” was the important mediator in the path from SL and student achievement, and the key variables of “emotions path” such as TTO or TC played different roles . HoweverTherefore, we hypothesized that TTO and TC might be the serial mediators in the path from SL to student achievement and proposed a serial mediation model see  to examiH1: School leadership have a direct impact on students’ RL.H2: Teacher trust in others mediate the relationship between SL and students’ RL.H3: Teacher commitment mediate the effect of SL on students’ RL.H4: Teacher trust in others and TC play the serial mediation model fit the relationship between SL and RL.ageM = 15.35 years, SD = 1.28).Whole group sampling was adopted to recruit all the Grade 8 students (aged around 15 years) from the 106 rural secondary schools in county D in western China. All the participating students were briefed about the survey by a trained graduate researcher and consented to participate in this study. And as the same time, their principals and class teachers were also invited to complete an online survey in December 2018 to provide information on SL, TC, and collaborative culture on line to explore the principal SL provide important support influence on student achievement. The “many to many” command were conducted with Stata software using school names as the matching identifier to match the school principals with their students. In total, the data from 34 school principals were matched with their 1,223 students  in the statistical analysis in this study. RL test was consisting of 22 questions on seven mathematical topics which had been covering the three ability dimensions of “search and retrieval,” “integration and interpretation” and “reflection and evaluation.”Student’s RL was assessed using the publicly released Chinese version of the PISA exam. An internationally standardized academic achievement test organized by the Organization for Economic Co-operation and Development (OECD), PISA aims to evaluate the academic performance of 15-year-olds in the subjects of reading. Its Chinese version was first applied to the 15-year-olds in Shanghai in 2009 , and latLeading and Teaching in Schools Survey Scale  and TTO , TTO  and RL . And TC was significantly and positively correlated with TTO , but not significantly with students’ RL a . TTO was significantly and negatively correlated with RL . This correlation matrix tends to support the following PROCESS analysis to examine the hypothesized model.The descriptive statistics and the intercorrelations among the studied variables for the total sample are presented in β = 0.104, p < 0. 01. Second, there was an indirect effect of SL on RL through TTO and TC. In particular, SL could predict TTO  and TC , and TTO could predict TC  and RL . And TC could predict RL, β = 0.097, p < 0. 05.The PROCESS results are presented in β = −0.085, SE = 0.023, 95% CI = , not crossing zero; (2) the indirect effect of SL → TC → RL was also significant, β = 0.013, SE = 0.007, 95% CI = , not crossing zero; (3) the indirect effect of SL → TTO → TC → RL was also significant, β = 0.033, SE = 0.016, 95% CI = , not crossing zero. All these results jointly indicated that teacher trust and TC had a serial mediation effect on the relationship between SL and RL (see The best-fit modelling (Model 6) results indicated that: (1) the indirect effect of SL → TTO → RL was significant, d RL see ; Table 3This study’s primary objective was to understand how TTO and TC jointly mediate the path from SL to RL in rural Chinese schools. The results have confirmed the serial mediating effects of TTO and TC. This section will discuss these findings and their implications for teacher development, SL, and improvement.This study found a significant direct impact of SL on students’ RL in rural Chinese schools. First, this might be attributed to the principals and their SL. This is because the rural schools in western China have so limited teaching resources that principals have to lead the managing and teaching simultaneously, and some even have to teach many classes . In thisSecond, the students, especially those in rural or disadvantaged contexts, are more sensitive to the principal’s instructional leadership. For example, This study has proposed and confirmed the hypothesized serial mediation model, indicating that TTO and TC mediate the path from SL to RL. This finding is a natural and further extension of the existing direction that TTO highly correlates with TC . First, Second, TTO is highly correlated with TC . This isThis study has proposed and established a serial mediation model to demonstrate the joint mediating effects of TTO and TC in the relationship between SL and RL in rural western China. First, a significant direct effect of SL was found, indicating that principals could impact students’ RL directly in rural Chinese schools. Second, TTO and TC sequentially and jointly mediate the path from SL to students’ RL, indicating that teachers’ roles are important and influential.However, this study has some major limitations. First, the number of students matched with the principals was small due to low return rates. This would have a certain influence on the conclusion. Second, the sample was limited to a county in rural China; thus, the findings could not reflect those schools in urban China. In the future, students from urban schools should be sampled to verify the findings of this study further.Nevertheless, this study has some important implications for school management and teacher development. First, the finding that TTO and TC play a serial mediating role indicates that more attention should be paid to building a caring and collaborative school culture. In particular, the distributed leadership could be established in rural schools to build up a collaborative culture that values trust, commitment, and collaboration. Towards this ends, the professional learning community could be developed in these rural schools . With thThe raw data supporting the conclusions of this article will be made available by the authors without undue reservation.The studies involving human participants were reviewed and approved by the Ethical Committee, Faculty of Education, Southwest University. Written informed consent to participate in this study was provided by the participant’s legal guardian/next of kin.HZ conducted the study. LL and HL conducted the data analysis and drafted the manuscript. All authors contributed to the article and approved the submitted version.This paper is supported by Decision Making Laboratory for Western Education and Human Development, National Social Science and Humanity Foundation (18ZDA338), and 111 Program (B21036); National Educational Double First-Class Program at Southwest University, Innovation Research 2035 Pilot Plan of Southwest University (SWUPilotPlan004); Key projects of Outstanding Young Talents Support Program in Colleges and Universities (gxyqZD2020107) Chongqing Social Science and Humanity Foundation (2022YC028); and Youth Project of Philosophy and Social Science Foundation of Anhui Province (AHSKQ2020D176).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


However, the energy intensive process and significant environmental impacts related to the production of Ordinary Portland Cement have shown the importance of searching for more sustainable materials. Concrete uses different aggregates added to the cement binder to lower, not only cost, but other factors like environmental burden, while maintaining good mechanical properties. This study analyzes the properties of fresh and hardened concrete incorporating recycled rubber to replace fine aggregate. Locally sourced 2 mm diameter rubber was incorporated in a regular strength concrete matrix into three different replacement levels, i.e., 3%, 5%, and 10%. Compression, tensile, flexural, and modulus of elasticity of hardened concrete were carried out in specimens aged 7, 14, and 28 days. In addition, non-destructive ultrasonic pulse velocity and rebound number tests were only performed on specimens aged 28 days. Once the tests were carried out, the fresh and hardened concrete properties were obtained. Similarly, the compressive and flexural strengths had the exact relationship between the values obtained. On the other hand, the modulus of elasticity tends to decrease due to the presence of the rubber. Consequently, it is recommended not to develop mix designs with more than 5% rubber because it is not meaningfully affected. The fine aggregate can be partially replaced by the rubber, keeping almost the same performance compared with sand-only counterparts. In addition, the life cycle assessment showed a reduction of up to 40% in the global warming potential. In fact, the 15% recycled rubber concrete mix has a climate change indicator of approximately 245 kg of CO Over the years, the construction sector has been a critical factor for economic and social development in a determinate place , where cThe raw materials for cement as well as aggregates that come from natural resources are generally over-exploited ,6,7,8. SDue to the meaningful environmental impact generated by the aggregates, several studies have been carried out to propose potential replacements for coarse and fine aggregates by using more environmentally friendly substitutes. For coarse aggregates, these can be replaced with recycled concrete , coconutSeveral studies have shown that a substitute for the aggregate may not meaningfully alter the mechanical properties of the concrete, depending on the type of substitute and quantity such that the concrete may keep the same mechanical characteristics or vary slightly ,31,32. R3 recycled rubber-reinforced concrete production has also been evaluated using life cycle analysis. Considering better mechanical properties obtained, recycled rubber can be used in concrete reinforcement, and it can reduce the environmental impact by taking the life cycle point of view into account.This research discusses the mechanical properties of fresh and hardened concrete, including resistance to compression, tension, and ultrasonic pulse velocity. The outcomes of this research work provide meaningful information concerning the fundamental properties of the concrete material using recycled rubber as a replacement for the fine aggregate. The performance of the fresh and hardened concrete was determined through the slump, air content, pressure, and destructive and non-destructive tests. In addition, the environmental impact of the 1 mThe study reveals the use of recycled rubber in the concrete mixture, which acts as a substitute for part of the fine aggregate according to the percentage established in each mixture. This material is vulcanized rubber granules and powder from mechanical temperature crushing environmental, end-of-life tires. For recycled rubber concretes to test, Holcim’s hydraulic cement was used in this study. The cement is commercially known as HE cements, which refers to “high early-strength”, and provides more resistant mixes to all ages than conventional general-purpose cement. According to the datasheet provided by Holcim , this maThe aggregates used in the mix were of three types: one type of coarse aggregate and two types of fine aggregate. The coarse aggregate used was No.67 according to ASTM C-33 , which iAdditionally, two chemical additives were used, a retarder and a superplasticizer. The retarder, commercially known as Sikaplast 2001-R, is a water reducer retardant fabricated to meet the technical requirement of standard ASTM C-494 type D . It main3, the specific weight is 1.15 to 1.27, and it has a percentage of humidity less than 0.75. According to the datasheet from ECSADE S.A. [The procedure to obtain recycled rubber particles is as follows: first, end-of-life tires are received, then classified according to the type from which they came (light car or heavy vehicle). Afterward, two types of shredding are carried out, one primary and one secondary . The priADE S.A.  the rubbFor aggregates to characterize, tests were run to measure properties such as fineness modulus, specific weight, moisture content, and absorption percentage. In the case of the moisture content, it is a value needed only from coarse aggregate; therefore, it is not performed on fine aggregate. The value was used to adjust materials quantities in the mix. The test procedure is as follows: first, determine the sample size. According to ASTM C566  the sampLike the moisture test, the absorption test is used to adjust material quantities in the mixture, especially in amounts of water. Since this test is used to calculate the percentage of water, the aggregate can absorb it while it is in contact. Following the recommendations of the ASTM C127 , the proThe nominal size of an aggregate is necessary for many aspects. In the same way, it is essential to know the distribution of particle sizes within a sample. For this study, the granulometry test was carried out for coarse and fine aggregates to identify the distribution and the fineness module . The staOnce the aggregates were tested mix design proceeded using the ACI method , in whicThe concrete mixes were prepared according to the designs. The first mix is the nominal concrete mixture; the others contained 3%, 5%, and 10% recycled rubber.It is essential to mention that the concrete mixer is Brand CF GUILCO with Model/Series 69,000–59,010, which has a maximum capacity of 30 L. Therefore, the concrete mix design shown in Once the concrete specimens are prepared after the mixing step, the concrete samples are placed in the individual molds. According to the ASTM C31 , each moOnce the specimens are processed, after 24 ± 8 h the concrete can be unmolded, coded, and later put into the curing room. ASTM C192  states tThe test method for the slump is carried out to determine the mix’s workability. Following the recommendations of ASTM C143 , the tooOnce the cylindrical specimens of 100 × 200 reach the desired age, i.e., 7, 14, and 28 days old, the test is carried out to determine the compressive strength. This test is carried out in two specimens for each age so that it can be determined at an average resistance. Following the directions in ASTM C39 , where iThe beam specimens were subjected to bending tests at 7 and 28 days. The three-point loading tests were carried out according to ASTM C78 , which cTwo cylindrical specimens of 100 × 200 mm aged for 28 days are tested to determine the modulus of elasticity according to the ASTM 469 standard . The proThe cylindrical specimen of 150 × 300 mm is used to prepare the samples aged for 28 days and perform non-destructive tests to determine the behavior and quality of the concrete. The ultrasound instrument is equipment that consists of two transducers connected to the central system: one emits ultrasonic pulses, and the second is the receiver. Considering the recommendations of ASTM C597 , the traInspect FEI scanning electron microscopy (SEM) was used for microstructural analysis to observe microstructural patterns in rubber-incorporated concrete. Once samples were tested, fractured pieces were collected and kept under ethanol to prevent hydration and carbonation. After drying for 24 h within a desiccator, the dried samples were put inside the SEM sample chamber to proceed to analysis.As seen in the results presented in According to the literature ,59, the Bisht and Ramana  indicateThe presence of rubber as sand replacement in samples causes a slight increase in flexural strength if the average results are obtained from the beam specimens see . The desUnlike the results obtained in tensile strength tests these results vary significantly, and it is evident that as more rubber is added the modulus of elasticity decreases . There iThe values in The rebound hammer test was carried out on the 150 × 300 cylindrical specimens for each design at 28 days, and the results are shown in Microstructural analysis was performed using SEM to identify potential interactions and patterns of rubber particles inside the samples as they were used as a partial replacement for fine aggregate, the sand for 0%, 3%, 5%, and 10%.The microstructure of selected samples and the distribution of rubber particles and their interface within the cement matrix are shown in 3 for the concrete mix system. The scope of the assessment evaluates the use of recycled tire rubber for the different mixes. The system has been modeled following scenario A of the ILCD handbook [Life cycle assessment (LCA) is established in the international normative ISO 14040 . The funhandbook . The schhandbook , converthandbook .The method used for this assessment is ReCiPe Method H , which a2 eq per m3 of concrete mix [The life cycle impact assessment performed for the system and options presented remarkable results in rete mix ,71. The The normalization for the results was also applied in order to get a better under-standing of the environmental performance of the scenarios in the analyzed systems. However, it is noticeable that the reduction in the impact as the percentage of recycled rubber increases. In fact, for the concrete using 10% recycled rubber, the impacts for the highly affected categories become positive. This behavior is because the reuse of the tires accounts for an end-of-life (EoL) scenario that positively impacts this waste stream. In addition, the dosage has been optimized, which allows for better performance in terms of sustainability. Recycled rubber reuse can replace 3.5 times sand or fine gravel used in concrete systems .The dosage with better environmental performance was the dosage that contemplates recycling 10% of rubber in the mix. A process contribution diagram can exemplify each item in the inventory and its impact on the environment. Additionally, the 10% mix was compared to a library found in the SimaPro software . The invRecycled rubber does not significantly alter the mechanical properties of fresh concrete and aged concrete for up to 28 days. Additionally, the use of recycled rubber can be used to reduce the environmental impact;Up to 5% of recycled rubber as a replacement for fine aggregate is feasible considering the mechanical properties of the desired concrete;2 eq, which means that the global warming potential significantly decreases with the increase in the amount of recycled rubber used in the concrete as fine aggregate.The life cycle assessment showed a reduction of up to 40% in the global warming potential. In fact, the 15% recycled rubber concrete mix has a climate change indicator of approximately 245 kg of COThe mechanical properties and environmental impact of recycled rubber as fine aggregate incorporated in fresh, 7-, 14-, and 28-days aged concrete have been investigated. All the specimens were analyzed using destructive tests including compression, tensile, flexural, and modulus of elasticity. In addition, some specimens were used to perform non-destructive tests such as the ultrasound pulse velocity and the rebound number. In addition, a life cycle assessment was made in order to quantify the environmental impact of the mix designs.


Litopenaeus vannamei with economic efficiency. The study involved two feeding trials, one with outdoor tanks (1 m3 volume) to evaluate shrimp growth performance over a 70-day feeding period and the other with indoor tanks (60 L) to evaluate feed digestibility over a 93-day period. The study used DL-methionyl-DL-methionine as the supplemental Met source. Under 0 and 6% FML conditions, total dietary Met levels of 0.69 and 0.82%, respectively, were required to maximize shrimp performance. In comparison, at 12 and 18% FML, a dietary Met content of only 0.58% was sufficient. Diets with 0 FML or with only 6% delivered the highest profit and return on investment compared to diets with higher levels. Overall, results indicated FML in shrimp feeds can be minimized or eliminated without impairing growth performance, providing Met requirement is met with appropriate sources.The shrimp feed industry is constantly looking for opportunities to minimize the dependency on expensive fish meal and to keep the industry profitable and sustainable. When fish meal is replaced with alternative protein sources available today, methionine (Met) is often the first limiting amino acid. This work investigated the optimal levels of fish meal (FML) and dietary Met required to optimize growth performance of juvenile Litopenaeus vannamei with economic efficiency. Four sets of diets were prepared to contain 0.00, 6.00, 12.00 and 18.00% FML. Each set was supplemented with DL-methionyl-DL-methionine (DL-Met-Met) to result in a total dietary Met (Met + Cys) content of 0.58 (1.05), 0.69 (1.16), and 0.82% (1.29%), on a fed basis. Shrimp of 1.00 ± 0.08 g were stocked in 60 outdoor tanks of 1 m3 with 100 shrimp/m2, allowing five replications per dietary group. Shrimp in all the groups were fed 10 times daily for 70 days. In a subsequent trial, dietary protein and amino acid digestibility of four FML groups, but only at high dietary Met levels (~0.82%), were evaluated in 40 60 L indoor tanks (11 replicates per diet) for 93 days with 70 shrimp/m2. Final shrimp survival , weekly weight gain (1.17 ± 0.08 g), apparent feed intake (13.3 ± 0.5 g of feed per stocked shrimp), and feed conversion ratio (1.18 ± 0.06) were unaffected by dietary FML level and Met content. Gained yield was adversely affected when FML was reduced from 18 and 12%  to 0 (1090 g/m2), but no change was observed at 6% (1121 g/m2). A significant interaction was detected between FML level and dietary Met. Under 0 and 6% FML conditions, higher levels of total dietary Met, 0.69 and 0.82%, respectively, were required to maximize shrimp BW. In comparison, at 12 and 18% FML, a dietary Met content of only 0.58% was sufficient. Overall, results indicated the use of FML can be minimized or completely eliminated without major detrimental effects on feed digestibility or shrimp growth performance, as long as proper supplementation of Met is carried out. Diets with 0 FML or with only 6% delivered the highest profit and return on investment compared to diets with higher levels.This work investigated the optimal levels of fish meal (FML) and dietary methionine (Met) required for maximum growth performance of juvenile  Industrially compounded shrimp feeds are among the largest global consumers of fish meal within the aquaculture industry ,2,3,4. AThe most common proteins adopted to replace fish meal in shrimp feeds are commodity by-products from the animal slaughtering industry  reduction with the dietary supplementation of DL-methionyl-DL-methionine (DL-Met-Met) under intensive culture conditions. Methionine (Met) is considered the most impacted essential amino acid (EAA) when fish meal is challenged. Recommended dietary Met levels in shrimp feeds have ranged between 0.7 and 1.0% of the diet (as-fed basis) depending on shrimp species , sourceaponicus ,46,47,48aponicus , cultureaponicus , water eaponicus , feed alaponicus ), and diaponicus ,54. HoweThis study consisted of two separate experimental stages. The 1st stage was designed to evaluate shrimp growth performance fed graded levels of FML and Met. A 2nd stage determined the apparent digestibility coefficients (ADCs) for crude protein (ACPDCs) and amino acids (AAADCs) of diets with graded levels of FML using a fixed dietary Met content.3 outdoor tanks (1.02 m2 bottom area × 0.74 m height), each equipped with a perforated lid on the top to avoid shrimp from escaping. The system operated with a continuous water recirculation at a rate of 100 mL/second (14.4% a day). Effluent water was drained into a 10 m3 sump with constant aeration which pumped surface water back to two header tanks of 20 m3 each. Water was then continuously distributed to rearing tanks with a 3-hp pump. No mechanical filtration was carried out in culture water during the study period. Water was fertilized prior to shrimp stocking by applying liquid sugarcane molasses along with a 500 µm shrimp feed  at a 1:1 ratio  over a five-day period. Culture water was then allowed to mix with strong aeration for three additional days before shrimp stocking.For the growth performance evaluation, an outdoor rearing system as described by Façanha et al. ,51,52 an2), each equipped with its own water inlet and outlet, aeration, and feeding tray. The rearing system was the same as described by Sabry-Neto et al.  × 7, where Bwi = wet shrimp body weight  at stocking, BWf = final shrimp BW at harvest, and t = number of days in culture. The gain in shrimp yield :2O3d = concentration (in %) of chromic oxide in the diet; Cr2O3f = concentration (in %) of chromic oxide in shrimp feces; Nd = concentration (in %) of CP and AA in the diets; Nf = concentration (in %) of CP and AA in shrimp feces.The concentration of CrThe cost of formulation of each individual diet was first calculated by using local market prices of each ingredient and feed additives . The pri® SPSS® Statistics 23.0  was used.One-way and two-way analyses of variance (ANOVAs) were used to compare the means of shrimp growth and economic performance as a function of the dietary FML inclusion and (or) Met content. One-way ANOVA was used to compare the means of economic efficiency. When significant differences were detected, they were compared two-by-two with Tukey’s HSD test. The significant level of 5% was set in all statistical analyses. The statistical package IBMp > 0.05, 2 (12% FML). However, yield did not differ statistically when shrimp were fed diets with 18, 12, or 6% FML, regardless of the dietary Met content. The elimination of FML did not affect yield when compared to shrimp fed 6% FML (1121 ± 68 g/m2), but it was significantly lower than those fed 12 and 18% FML. The increase in the dietary Met levels from 0.58 (1127 ± 56 g/m2) to 0.69 (1145 ± 45 g/m2) or 0.82% (1135 ± 84 g/m2) had no statistical effect on gained yield or a significant interaction with FML level. Shrimp fed the CTL (1040 ± 33 g/m2) achieved a lower yield compared to those fed diets containing 0.69% Met at all levels of FML, except the highest (18%). At 0.58% Met, higher FML levels were required (12 and 18% FML) to significantly increase yield beyond the CTL. In comparison, at 0.82% Met, there was no significant difference in yield between shrimp fed the CTL and the experimental diets, except when 18% FML was used. In this case, yield was higher for the latter compared to the CTL. In outdoor tanks, shrimp final survival was high (92.7 ± 4.7%) and unaffected by dietary Met content, inclusion level of FML, or their interaction (p > 0.05). Shrimp fed experimental diets also grew at a similar rate compared to those fed the CTL. Apparent feed intake (AFI) did not differ statistically as a result of FML level or dietary Met content (p > 0.05). However, some of the experimental diets showed a higher AFI than the CTL. FCR was generally low, between 1.15 to 1.22. FCR was also not affected by variations in FML or dietary Met. FCR for experimental diets was within the range of the CTL (1.23 ± 0.02). Exceptions were diets with 6% FML containing 0.69% Met and 18% FML with 0.58% Met, which resulted in statistically lower values compared to the CTL. Shrimp weekly growth rate exceeded 1.1 g regardless of the dietary treatment. No difference or significant interaction was detected in growth between shrimp fed different levels of dietary Met and/or FML (p < 0.0001). With 0 and 6% FML, higher levels of dietary Met, i.e., 0.69 and 0.82%, respectively, were required to maximize shrimp BW. However, a complete withdrawal of FML was detrimental to shrimp BW even at 0.82% Met. In comparison, at 12 and 18% FML, a dietary Met content of only 0.58% was sufficient to enhance shrimp BW.Final shrimp BW at harvest ranged between 12.61 ± 0.92 (0% FML and 0.58% Met) and 13.92 ± 0.51 g , but the latter did not differ from 6% (p > 0.05). Similarly, reducing dietary Met content from 0.82 to 0.58 and 0.69% resulted in a significantly lower BW in L. vannamei (p < 0.05). However, no difference was detected in BW between shrimp fed 0.58 and 0.69% dietary Met (p > 0.05). At the lowest level of dietary Met, i.e., 0.58%, diets containing 12 and 18% FML outperformed the diets with 6 and 0% FML (p < 0.05). A similar but non-statistically significant trend was detected with higher levels of dietary Met, i.e., 0.69 and 0.82% (p > 0.05). The reduction in the dietary inclusion of FML resulted in a significantly lower BW at harvest, especially with diets containing 0 and 6% FML. The highest BW was achieved when shrimp were fed 12 and 18% FML (p < 0.05).The amount of dietary Met required to maximize shrimp BW was also a function of FML level. When FML was decreased to 6% or 0%, the highest BW was achieved with 0.69–0.82% Met, but at 12 and 18%, a minimum of 0.58% Met was sufficient. Thus, in general, as FML levels were challenged, higher levels of total dietary Met were required to maximize shrimp BW. Finally, shrimp fed the CTL achieved an equivalent BW compared to those fed 0 and 6% FML. Levels of FML higher than 6% regardless of dietary Met content resulted in significantly higher BW compared to the CTL (There was an increasing trend towards in apparent crude protein digestibility (ACPDC) with higher dietary inclusion levels of FML . ACPDCs p < 0.005). Survival reached a mean of 87.5 ± 7.8% (p > 0.05). At harvest, shrimp fed 0% FML grew at 0.62 ± 0.04 g/week and achieved 12.69 ± 0.55 g final BW, both significantly lower than other dietary treatments (p < 0.05). However, no statistically significant differences were detected for gained shrimp yield (557 ± 80 g/m2) and FCR (2.68 ± 0.37). There was a significantly lower AFI when shrimp were fed 0 and 6% FML, but the later did not differ statistically from 12 and 18% FML (p > 0.05). In indoor tanks, shrimp fed a diet deprived of FML achieved the highest final survival compared to other dietary treatments  were driven by FCR, yield, shrimp final BW, and formula costs, i.e., feed sales price. Formulation costs ranged from a minimum of 0.706 (0% FML with 0.56% Met) to a maximum of 0.943 USD/kg , as opposed to the dietary levels of Met which showed no effect (p > 0.05). There was also no significant interaction between FML levels and dietary Met content for total production cost, gross revenue, profit, and ROI (p > 0.05). By taking into account the total production costs and shrimp performance data, it was possible to determine the ROI for each individual rearing tank and dietary treatment . Economip > 0.05). Gross revenue with 12% FML (4.78 ± 0.42 USD/kg) was higher than 0% FML (4.32 ± 0.28 USD/kg), but it did not differ from 6% (4.54 ± 0.41 USD/kg). On the other hand, the lowest profits were achieved with higher levels of FML, i.e., 12% (0.90 ± 0.38 USD/kg) and 18% (0.59 ± 0.28 USD/kg), although the former did not differ statistically from 0% (1.07 ± 0.27 USD/kg) and 6% FML (0.95 ± 0.30 USD/kg). Production cost reduced progressively with lower dietary inclusions of FML, from a high of 4.10 ± 0.13 (18% FML) to a low of 3.24 ± 0.10 USD/kg (0% FML). There was on average a reduction in 0.86 USD/kg in production cost when FML was completely eliminated, i.e., from 18% to 0 FML. Although gross revenue was impacted with a reduction in FML, it was not significantly different between diets containing 6, 12, and 18% FML . At no FML, ROI was significantly higher than 12 and 18% FML. At moderate levels of dietary inclusion, i.e., 6 and 12% FML, no differences in ROI could be observed. L. vannamei is dependent on appropriate dietary Met (Met + Cys) levels. This can be achieved through the supplementation with crystalline Met or by raising protein ingredients rich in these intact AAs. This is consistent with other work which indicates the importance of supplemental Met while challenging FML levels [This study has demonstrated that dietary FML levels and Met (Met + Cys) content and their interaction significantly impact final shrimp BW. The responses in BW as a function of FML level varied according to the dietary Met (Met + Cys) content. At the lowest dietary Met (Met + Cys), i.e., 0.58% (1.05%), we observed that FML could only be reduced from 18 to 12%. Further reductions led to a reduced shrimp BW at harvest. At moderate levels of dietary Met, i.e., 0.69% (1.16%), FML could be completely eliminated without any impact to shrimp BW, but with an adverse effect on yield. In comparison, at the highest dietary Met, i.e., 0.82% (1.29%), FML could be reduced from 18 to 6%, but complete withdrawal negatively impacted BW. Therefore, the levels of dietary Met (Met + Cys) required to maximize shrimp BW at 0 and 6% FML ranged between 0.69 (1.16) and 0.82% (1.29%), while at 12 and 18%, only 0.58% (1.05%) was needed. Notably, Met apparent digestibility coefficient was not affected by the FML across diets, which means that even on a digestibility basis this difference will hold true. Therefore, it is clear that an effective reduction in FML in diets for L levels ,42. L. vannamei was reached at 6%. This finding is corroborated with the work of Suárez et al. [L. vannamei (0.3 ± 0.1 g) under clear-water conditions for 95 days. The authors replaced FML with SBM while keeping the dietary levels of Met + Cys (1.0–1.2%) consistent with the use of canola meal, a natural source of sulfur-containing AAs. They found that a combination of SBM and canola meal was able to reduce FML from 30 to 6% but not beyond that. In the current study, to completely withdraw FML from the diets, SBM levels were increased to 46.08%. In this case, most of the dietary protein came from plant sources  with only a small portion (4%) derived from animals (squid and krill). We found that even at higher levels of dietary SBM (45% of the diet), the ADCs for dietary protein and AAs were adequate (>80%). Thus, the reduced shrimp growth performance with 0% FML was likely driven by other factors, including a poorer feed attractability. We could not observe any negative response in AFI with the outdoor rearing system likely because shrimp were fed with feed restrictions. However, in the indoor systems, when shrimp were fed in excess, there was a reduced AFI when shrimp were fed diets containing 0 and 6% FML. We found that under outdoor and indoor tank conditions, the optimal dietary FML level without an adverse effect on the growth performance of z et al. , who raiL. vannamei [2 [2 [2 [2). With a lower density, the nutrient contribution of naturally available food sources to shrimp growth can be significant and can lead to much higher levels of FML replacement. Their formulas also combined other protein sources for FML replacement in addition to SBM. For example, Amaya et al. [In other work, plant-based feeds ,7 and fevannamei ,67,68,69namei [2 ; 35 shriIn the current study, from the economic point of view, eliminating FML was as competitive as including 6% FML, with both being more advantageous than 12 and 18% FML. The production costs of diets containing lower levels of FML exceeded the benefits of a higher revenue, resulting in greater profit and ROI. The cost of FML was the main driver for a higher production cost recorded for diets 12 and 18% FML. In comparison, total dietary Met content had no effect over economical parameters, including production costs. Results from the present study show that a correct balance of FML and dietary Met has a critical effect on whiteleg shrimp performance. Shrimp final survival, growth, FCR, and the dietary protein and amino acid digestibility were not negatively affected by a reduction or complete elimination of FML with a proper balance with CAAs, including Met. However, while gained shrimp yield is reduced when FML is withdrawn, dietary inclusion levels of 12% or higher leads to increased costs, which are not offset by higher revenues. In conclusion, the total amount of dietary Met needed to maximize shrimp growth performance depends on the amount of dietary FML. Higher amounts of supplemental DL-methionyl-DL-methionine reduces the reliance on FML. A total dietary supplementation of DL-Met-Met of 0.34% can reduce FML inclusion from 18 to 6% without any negative effect on shrimp performance. Overall, results indicate that the use of FML can be minimized or completely eliminated without major detrimental effects on shrimp performance, as long as methionine requirement is met with proper supplementation of CAAs. Feeds with 0 FML or with only 6% with levels of dietary Met (as-fed basis), i.e., 0.69 and 0.82%, respectively, deliver the highest shrimp growth performance, profit, and return on investment compared to diets with higher levels.


The use of WGP improved the FS of CCs, as determined by the experimental results. The highest FS was obtained when 10% and 15% WGP was utilized as a cement and fine aggregate replacement, respectively. The modeling approaches’ results revealed that the support vector machine method had a fair level of accuracy, but the bagging regressor method had a greater level of accuracy in estimating the FS. Using ML strategies will benefit the building industry by expediting cost-effective and rapid solutions for analyzing material characteristics.Using solid waste in building materials is an efficient approach to achieving sustainability goals. Also, the application of modern methods like artificial intelligence is gaining attention. In this regard, the flexural strength (FS) of cementitious composites (CCs) incorporating waste glass powder (WGP) was evaluated via both experimental and machine learning (ML) methods. WGP was utilized to partially substitute cement and fine aggregate separately at replacement levels of 0%, 2.5%, 5%, 7.5%, 10%, 12.5%, and 15%. At first, the FS of WGP-based CCs was determined experimentally. The generated data, which included six inputs, was then used to run ML techniques to forecast the FS. For FS estimation, two ML approaches were used, including a support vector machine and a bagging regressor. The effectiveness of ML models was assessed by the coefficient of determination (R Severmissions –27. The missions ,29. As amissions –32. Partmissions . WG is cmissions . Some glmissions . Around missions , posing 2 [2 discharges [To manufacture glass, silica must be melted for hours at a high temperature . The amo2 . Glass m2 . So, it 2 . Another2 ,42. Ther2 ,44. Consscharges ,46.Flexural strength (FS) is an important factor to consider when designing concrete structures, as it influences flexural cracking, deflection characteristics, brittleness ratio, and shear strength . The sel2), the k-fold approach, statistical tests, and the variance in projected outcomes (errors). This research is new in that it evaluated the FS of CCs incorporating WGP using experimental and ML approaches, involving both single and ensemble ML approaches. Material collecting, sample casting, curing, and conducting tests require a great deal of time, money, and effort in experimentally-based investigations. The building industry will profit from the elimination of these difficulties by utilizing innovative approaches like ML. Therefore, this research aimed to increase understanding regarding the application of ML approaches to predict material attributes. The obtained data from the experimental program may be utilized to train ML systems and assess material characteristics. This work employed six input parameters and 117 specimens to predict the FS of CCs incorporating WGP and evaluate the effectiveness of each ML technique.This research employed experimental and ML strategies to estimate the FS of CCs incorporating waste glass powder (WGP). The WG was gathered from local construction detritus, cleansed, and ground into a powder. The CC samples were cast with different concentrations of WGP as a fine aggregate and cement replacement (0–15%). The FS of WGP-based CC was determined using experimental approaches at 28 days of age. Following the completion of the experiments, the obtained data were utilized to develop ML prediction models. Support vector machine (SVM) and bagging regressor (BR) were used to accomplish the research’s objectives. SVM is a single ML technique, whereas BR is an ensemble ML technique . Each mo3, and specific gravity was 2.65. WG was gathered from nearby construction waste, cleaned, and mechanically ground into powder in the lab, and then sieved through a number 200 mesh. Three kinds of mix designs were selected for CCs, and their details are provided in Locally accessible fine aggregate and Portland cement were gathered, whilst superplasticizer and silica fume were bought from Pakistan’s PAGEL Chemicals. The fineness modulus of fine aggregate was 2.6, bulk density was 1230 kg/m2 score of the predicted outcome indicates how well the models operated. The R2 value suggests the level of variance; a number near 0 denotes greater variation, whilst a value nearby 1 suggests that the experimental results and prediction model are almost perfectly suited [ML approaches require a comprehensive range of input parameters to build the anticipated output . With thy suited . AdditioSVM is a subset of supervised ML algorithms that are used to assess data for classification and regression. A discrete vector, i.e., a line or plane with the biggest feasible gap, is used to differentiate the forms of the various classifications in an SVM technique, which represents the data as points in space. A schematic diagram of the BR method is shown in 2 value is higher, then the ML technique is more accurate. Additionally, the process needs to be repeated ten times for the desired result to be realized. The incredibly high precision of the model is largely due to this effort. Errors assessment was also used to statistically compare the precision of different ML methods . Eqs . Eqs , derived2 in the glass’s composition [2 in the mix to form improved calcium-silicate-hydrate (C-S-H) gel, improving the characteristics of CCs [position  interacts of CCs ,75. At gs of CCs  and cemeThe FS of the samples incorporating WGP as a fine aggregate substitute is displayed in 2 result of 0.88 indicated that the SVM technique for estimating the FS of CCs is adequate. The variation in experimental, anticipated, and divergent values (errors) for the SVM algorithm is shown in The results of the SVM method applied to the estimation of the FS of CCs with varying amounts of WGP are displayed in 2 of 0.93, implying greater accuracy. The BR method’s error distribution is shown in Results of the BR technique applied to predict the FS of the CCs incorporating WGP are presented in 2, MAE, and RMSE for the purpose of validating the models using the k-fold approach. 2 was 0.69, and the SVM model was 0.61 on average. According to the k-fold test, the BR model with the smaller deviations and higher R2 is the most effective in forecasting the FS of CCs incorporating WGP.2. The use of WG in CCs as a cement and fine aggregate substitute has the potential to be an environmentally beneficial technique. Thus, avoiding waste, conserving natural raw materials, and reducing CO2 emissions are some of the aspects due to which the use of WG in CCs will lessen their negative effects on the environment. Therefore, this research aimed to expand our understanding of WGP’s role in CCs by integrating experimental and ML-based modeling techniques. Different percentages of WGP were used to substitute cement and fine aggregate in the casting of CC samples (0–15%) with a 2.5% increment. The experimental findings showed that adding WGP enhanced FS. As a cement substitute, a WGP concentration of 10% yielded the highest FS, up to 32% more relative to the reference mix. Amongst the potential reasons are the filling effect and the pozzolanic reactivity of WGP. The matrix is dense and compact due to the filling effect, which decreases the void ratio. A higher percentage of SiO2 in glass’s composition combines with Ca(OH)2 in the matrix to develop improved C-S-H gel, which increases the material’s characteristics [The FS of CCs with WGP as a partial substitution for cement and fine aggregate was evaluated in this work using both experimental and modeling methodologies. There is an excessive volume of WG produced globally, and most of it is disposed of in landfills, where it poses health and environmental risks to people and the atmosphere . Additioeristics ,75. Sinceristics . To get eristics . WGP waseristics . Therefo2 for the BR model was 0.93, which was higher than the R2 for the SVM (0.88). Lower error values were found for the BR model when compared with SVM, confirming its superior accuracy. Nevertheless, the SVM model’s prediction was also accurate and in agreement with the experimental data. It has been established via previous research that the BR approach is more accurate compared to the individual ML methods in predicting the strength characteristics of various materials [2 value. As a result, the ensemble ML models produced more precise results than the individual. The construction industry may profit from this type of research because it will facilitate the development of efficient methods for assessing material attributes quickly and cheaply.The ML models were executed on the organized experimental data. When attempting to estimate the FS of WGP-based CCs, both a single ML technique (SVM) and an ensemble technique (BR) were utilized. Both approaches were evaluated for their exactness in predicting outcomes. The Raterials –80. For aterials  forecastaterials , making The purpose of this study was to study the flexural strength (FS) of cementitious composites (CCs) incorporating waste glass powder (WGP) by using both experimental and ML methodologies. The FS of samples was calculated via experiments, and the resulting data sample was utilized to build ML prediction models. Support vector machine (SVM) and bagging regressor (BR) are two machine learning (ML) techniques that were used to make predictions about the FS. The findings of this study are:The experiments’ results showed that adding WGP might improve the FS of CCs. When used as a cement substitute, WGP increased FS by up to 32% when used at a 10% concentration. Both the filling effect and the pozzolanic feature of WGP have been anticipated as potential explanations.At 15% replacement, FS was 36% greater than the reference sample when WGP was utilized as a fine aggregate substitute in CCs. The pozzolanic nature of the glass and the fact that WGP was finer than finer aggregate both have the potential to explain the improved FS.2 of 0.88, while the BR technique was more precise with an R2 of 0.93 in predicting the FS of CCs incorporating WGP.Based on the results of the ML models, it was discovered that the SVM model was accurate with an R2 and lower error rates were indicators of how well ML models performed. SVM and BR models were found to have MAPEs of 2.5% and 2.0%, respectively. The MAPE values demonstrated that the BR model provided the most accurate forecasts of FS.Statistical and k-fold evaluations verified the effectiveness of the used model. Improved R2 emissions.Sustainable development is aided by the use of recycled glass in building materials because it prevents the waste glass from being dumped, conserves natural raw materials, generates cost-effective materials, and reduces COThe construction industry may benefit from the adoption of cutting-edge techniques, such as ML because it will speed up the development of more cost-effective and time-efficient ways for determining material properties.This study was limited to investigating the effect of using WSP on the flexural strength of the CCs. However, for the potential engineering applications of the material, future research is directed to fully explore the other aspects as well, such as compressive and split tensile strength and durability. Additionally, the strength of CCs can also be affected by other factors, such as the water-to-binder ratio, curing conditions, the quality of raw materials, and environmental effects (temperature and humidity), so it will be necessary to develop a dataset containing these input variables in the future for ML modeling.