To evaluate a minute-by-minute monitoring algorithm against a periodic early warning score (EWS) in detecting clinical deterioration and workload. Periodic EWSs suffer from large measurement intervals, causing late detection of deterioration. This might be prevented by continuous vital sign monitoring with a real-time algorithm such as the Visensia Safety Index (VSI). This prospective comparative data modeling cohort study (NCT04189653) compares continuous algorithmic alerts against periodic EWS in continuous monitored medical and surgical inpatients. We evaluated sensitivity, frequency, number of warnings needed to evaluate (NNE) and time of initial alert till escalation of care (EOC): Rapid Response Team activation, unplanned ICU admission, emergency surgery, or death. Also, the percentage of VSI alerting minutes was compared between patients with or without EOC. In 1529 admissions continuous VSI warned for 55% of EOC (95% CI: 45-64%) versus 51% (95% CI: 41-61%) by periodic EWS. NNE for VSI was 152 alerts per detected EOC (95% CI: 114-190) compared to 21 (95% CI: 17-28). It generated 0.99 warnings per day per patient compared to 0.13. Time from detection score till escalation was 8.3 hours (IQR: 2.6-24.8) with VSI versus 5.2 (IQR: 2.7-12.3) hours with EWS (P=0.074). The percentage of warning VSI minutes was higher in patients with EOC than in stable patients . Although sensitivity of detection was not significantly improved continuous vital sign monitoring shows potential for earlier alerts for deterioration compared to periodic EWS. A higher percentage of alerting minutes may indicate risk for deterioration.The online version contains supplementary material available at 10.1007/s10916-023-01954-z. Inpatients’ clinical deterioration is strongly related to morbidity and mortality, and frequently preceded by vital signs abnormalities –8. The lMost EWS protocols limit the assessments to once every eight hours, resulting in hours without observations and possibly failure to timely identify clinical deterioration , 12–14. Continuous vital sign monitoring is emerging on the wards with the introduction of wireless monitoring solutions –18. ElimMoreover, most EWSs are validated only for periodic vital sign measurements. Few scores are validated in combination with continuous vital sign monitoring which would require an automated real-time algorithm. The Visensia Safety Index (VSI)  is such an algorithm. The VSI works by comparing the combined patterns of continuously monitored vital signs to a database of normal vital signs . The VSIIn 2018, a continuous vital sign monitoring system with the ViSi Mobile  wearable device was introduced at our medical and surgical nurse wards . With thThe primary objective of this study is to determine the potential added value of every-minute assessment using an alerting score developed for use with continuous monitoring, in detecting clinical deterioration requiring escalation of care (EOC). We hypothesize that continuous monitoring plus VSI outperforms periodic EWS with continuous vital signs available when it comes to early warning for EOC. We also compare the total number of warnings arising from both scenarios, to explore the potential added workload. As a secondary objective, we explore the potential value of the number of alerting minutes of continuous VSI between patients that require EOC or not.Since June 2018, all patients admitted to two selected wards are routinely connected to the ViSi Mobile device, that continuously measures heart rate, respiration rate, blood oxygen saturation, skin temperature, and cuffless blood pressure , 24, 25.This study was performed following the STROBE guidelines for observational cohort studies. With this prospective comparative data modeling cohort study, we explored how often and when warnings were generated on either regular periodic EWS or continuous VSI calculation in well-defined clinical situations requiring EOC. We compared sensitivity, number needed to evaluate (NNE), number of warning scores per patient per day, and the time between initial warning and EOC. Also, the percentage of VSI alerting minutes was compared between patients with or without EOC.All patients, 18 years and older, admitted to the 34-bed medical ward or 26-bed gastrointestinal surgical ward of our academic hospital in the Netherlands from August 2018 to July 2019 were included. If patients were not connected within the first 12 hours or had an admission that was estimated to be shorter than 24 hours, they were excluded from the analysis. Relevant changes in clinical condition, interventions, occurrence of complications, new diagnoses and clinical endpoints such as RRT calls, ICU admission, discharge, or death were prospectively recorded in a pseudonymized research database  by two MD’s using a purpose-designed electronic form, analyzing all EMR orders and notes.In order to evaluate the continuous monitoring plus VSI, we used the minute-by-minute data to calculate a Visensia Safety Index. This is a commercially available FDA-approved risk score with a CE mark for minute-by-minute assessment of the continuous vital sign monitoring data. The VSI used four vital signs, namely, blood oxygen saturation, respiratory rate, heart rate and blood pressure, but only requires at least three of the four vitals for its calculation. It can also use core temperature as a fifth parameter; however, we did not use this function as this was not continuously measured. The algorithm combines available vitals and constantly scores these against a range of normal vital signs. It also has smooths out extreme measurements to filter for faulty measurements using surrounding reassuring data. A VSI ≥ 3 indicates predicted critical instability within the coming 6 hours . The curIn our modeling, an alerting value of one of these scores starts a ‘warning period’. This warning period can either result in an EOC endpoint, or return to a normal clinical situation without an EOC occurring. A warning period arbitrarily ends after 4 hours. This 4-hour period was chosen as it corresponded to the measurement interval advised by the current protocol for an EWS above 3. If an additional alert (increased EWS or VSI) occurred within that 4-hour period, we considered this alert related to the initial alert. In these cases, the period was lengthened with another 4 hours from the latest alert. To allow comparison, the intervals with continuous monitoring in which no alert occurred were limited to a maximum of 8 hours, which equals the duration of a regular periodic monitoring interval in stable patients.Possible clinical outcomes were either discharge to home, or a composite endpoint Escalation of Care, defined as either RRT activation, unplanned ICU admission, need for emergency surgery, or death. These events were extracted from the EMR using RRT orders, transfer orders to the CCU or ICU if these were not expected to occur at admission, or surgery orders that were not planned 12 hours ahead of the procedure. When a EOC has occurred, this patient would not be used for further analysis of new EOC’s, with exception of RRT-activations, which were assessed as new escalations if at least 24 hours apart. Detection of EOC was the primary outcome of the study.Descriptive statistics are presented as the mean with standard deviation (SD) or median with interquartile range (IQR). For confidence intervals of proportions, we used the standard error to calculate a 95% confidence interval (95% CI). For non-normally distributed data, Mann-Whitney U tests were used to detect differences in shape and spread as well differences in medians.For all warning periods, it was determined whether the elevated EWS or VSI was a true positive, a false positive or true negative warning with respect to a reached EOC. If an EOC occurred outside a warning period, it was counted as a false negative warning. The elapsed time between the initial alert and a successive EOC (true positives) was compared between both scenarios.As a measure of added workload as result of implemented continuous monitoring, the number needed to evaluate (NNE) were determined as ratio of false to true warnings. Crosstabs were created for warning periods versus EOC to calculate sensitivity or recall (TP/EOC), positive predictive value or precision (PPV = TP/(TP+FP)) and the number of warning periods needed to evaluate (NNE = 1/PPV) to indicate one true warning. To convert this to a scalable clinical number, we normalized the NNE with respect to the number of patient admission days, resulting in a number of warnings per patient per day.Secondary, using the continuous monitoring data, we divided number of warning minutes by the number of available monitored minutes (fraction of warning minutes) and compared this between patients who ended in EOC or with discharge. This was done for the first 120 admission hours (median admission time) to avoid outliers. In addition, we calculated the fraction of warning minutes during the last three days before an EOC had occurred e.g., 0-24 hours, 25-48 hours and 49-72 hours. This was visualized in Fig. All statistical analyses were performed using IBM SPSS 23 . Figures were made using IBM SPSS 23 and GraphPad Prism 9 .A total of 1529 of 2303 admissions were eligible for analyses because they were connected to continuous monitoring within the first 12 hours of the admission at the ward that lasted for longer than 24 hours. Of these patients, 106 (7%) encountered an EOC. Table A total of 38,547 periodic vital sign measurements and 10,074,490 minutes of continuous vital sign monitoring were analyzed across 8,890 patient days. Of the expected continuous vital sign monitoring data (one registration every minute) 79% was available. Common reasons for missing continuous data were unavoidable monitoring interruptions during diagnostics or therapies, the device not being connected to the network, or other technical errors. In 170 patients monitoring was discontinued due to various reasons such as delirium, contact allergies, at the initiation of palliative care, or late opting out of the monitoring. Hereby these patients were also stopped being followed-up. For these patients no further endpoint was registered.Table Time from initial warning to EOC is compared in Fig. For our secondary outcome, we observed using continuous vital sign monitoring plus VSI, that the percentage of the alerting time in patients whose admission ended with an EOC was higher than in the patients who were discharged without EOC, shown by a difference in distribution in Fig. In this study we explored the potential value and the influence on the workload of a warning score developed for the use with continuous monitoring over periodic EWS calculation in detection of clinical deterioration ending in escalation of care. It was shown that continuous vital signs monitoring in combination with an appropriate risk score algorithm  equaled periodic vital sign measurements in terms of sensitivity and has the potential to detect clinical deterioration earlier. However, the PPV is significantly lower than that of periodic monitoring. Continuous monitoring plus VSI resulted in a higher fraction alerting time in patients with an EOC.Clinical decision making during our observations was based on the EWS protocol, so it was expected that a retrospective modeled score would reach the same sensitivity for EOC as the periodic EWS. Furthermore, the periodic EWS was supported with clinically available continuous monitoring data. Therefore, the added value of the minute-by-minute VSI for indicating clinical deterioration is assumed underestimated. The earlier detection can be explained by the continuous measurements, alerting for deterioration hours before a planned assessment .The use of the VSI has other benefits. It used only four vitals, that can be derived from current automated monitoring systems. Even in case of temporarily unavailability of one of the vitals, the VSI can be calculated. Using fewer vitals than previous studies, our findings are in line with recent reviews, which shows that continuous monitoring detects deterioration earlier, even without advanced analysis , 22.Screening tests for clinical deterioration need to balance between workload and safety i.e., between an acceptable number of false positives and an adequate sensitivity –29. ContCurrent literature compares continuous monitoring to periodic EWS and treats both as a surveillance system for acute deterioration needing immediate escalation , 22. TheThe fraction of alerting minutes could be such a risk assessment. The higher fraction of alerting minutes in the EOC patient group combined with the ascending trend towards the moment of EOC, suggests that the increasing number of alarms may be a precursor to a dysregulation. These apparent false positives do seem to lead the healthcare provider to the patients in need. Other studies report frequent and significant periods of hypoxemia, tachycardia and hypotension in ward patients, not found with periodic measurements. It is suggested that these could be early signs of deterioration , 26, 33.This study is relatively large compared to current literature, being based on the clinical course during 8889 admission days , 21, 22.Early detection on its own is not enough to prevent deterioration. Suitable follow-up protocols need to be formed, actuating a proper response , 21, 22.Continuous vital sign monitoring with an appropriate warning score (VSI) showed an equal sensitivity to continuous vital sign monitoring with periodically calculated EWS for escalation of care while alarming more frequent. Continuous VSI has the potential to identify clinical deterioration earlier, while using fewer vital sign parameters. In addition, the fraction of alerting minutes may indicate patients at risk for clinical deterioration.Supplementary file1 (PDF 311 KB)Supplementary file2 (DOCX 16 KB)Below is the link to the electronic supplementary material.


Ordinary Portland cement is the highest produced cement type in the world, however its production is high energy consumption means expensive, huge natural resource consumptive, and creating high environmental pollution. Hence many researchers studied to reduce the effect of ordinary Portland cement by substituting artificial and natural supplementary cementitious materials (SCMs) commonly in a concrete/mortar mixture. However, the comprehensive effect of different SCMs on various properties of cement composite materials are not well known. So the present study sought to review the effect of different natural and artificial SCMs on the durability and mechanical properties of cement composites, especially due to their doses, types, chemical composition, and physical properties. Hence the review shows that many SCMs used by literatures from different places satisfy ASTM replacement standard based on their chemical compositions. Also, the review indicated as adding 5–20% of different SCMs positively affect mechanical properties, durability, and microstructures of the cement composite materials, specifically as most researchers found isolately adding of 15% SCMs such as bentonite, kaolin, and biomass, 20% addition of volcanic ash and 10% employment of fly ash, silica fume, and zeolite to the cement composites achieves the most optimum compressive and split tensile strength. These observations reveal that most natural pozzolana can more replace cement to give optimum strength, hence can more reduce energy consumption, production cost, and environmental pollution comes due to cement production. Furthermore, most researchers found employing different SCMs generally improves durability, however there is a limited study on the effect of silica fume on water absorption and acidic attack resistance of cementitious materials. Therefore, it is recommended that future research should also focus more to know the effect of silica fume on the durability of cement composites. Hence tironment .2 into the environment [2 emission comes due to cement production [Especially the production of ordinary Portland cement is high energy consumption means very expensive, huge natural resource consumption, and creates environmental problems. But, due to the rapid growth of the population in the world, the demand for ordinary Portland cement increasing globally ,11. Howeironment . Therefooduction . This isoduction . However1.12 emission [Pozzolan is SCM commonly used as cement replacement in the concrete composite for a lot of significance in improving concrete performance, reducing cement consumption with significantly reducing COemission . This isC–S–H. These improve the finer pore structure of the cement matrix compared to reference Ordinary Portland cement. Thus the concrete matrix becomes less permeable which can improve concrete durability [Besides to these employing pozzolanic SCMs beneficial in the consumption of calcium hydrate in cement and producing secondary rability . Durabilrability ,52.2 emissions [In addition to improving durability, employing of SCMs beneficial for lowering cement production costs and environmental impact . The sammissions . Also, smissions ,49, imprmissions .Additionally, SCMs from by-product or waste reflects promising performance as a partial replacement of cement composite materials which can reduce the consumption of natural resources  and reduAlso, Ivashchyshyn et al.  studied Besides these, concrete is alkaline and chemical attack resistant, though can be affected by the acid attack in liquids having pH value below 6.5 and severe at below 5.5 and very severe below 4.5 pH value, that is because of easy dissolution and leaching of calcium hydroxide in hardened concrete, so SCMs is beneficial by its micro filling ability that can protect the entrance of acids from the reduction of concrete durability ,80,81.Furthermore, the incorporation of industrial by-products such as slag, fly ash, and silica fume positively affects concrete mixture ,81. Ceme1.21.2.1C618 [2), Aluminum oxide (Al2O3), and Iron oxide (Fe2O3) greater than 70% for natural pozzolanic materials added to concrete manufacturing. This is due to the reason SCMs are used to reduce the production cost of cement and environmental pollution, but as well those three oxides have the potential to actively react with free lime from clinker to produce calcium silicate hydrate (C–S–H) and calcium aluminate silicate hydrates (C-A-S-H) which is the crucial compound that improve strength, durability and make dense microstructure of cement composite materials. In addition to that increasing the sum of SiO2, Al2O3 and Fe2O3 oxides increases the strength, mainly increasing of strength caused by SiO2. That is because SiO2 is the most important oxide which can improve the pozzolanic reaction in pozzolana [The pozzolanic reaction of natural SCMs mainly depends on their chemical composition, chemical reactivity index, and mineralogical composition . Also, SC618  requiremozzolana .Table 1C1.2.2C618 [2), Aluminum oxide (Al2O3), and Iron oxide (Fe2O3) greater than 70% for pozzolanic materials added to concrete manufacturing and also can see as the summation of three oxides SiO2, Al2O3, and Fe2O3 of most of the artificial supplementary cementitious materials are more greater than the natural SMCs, that is also known as the summation of those three oxides can significantly play important role in the pozzolanic reaction. Hence increasing the sum of those three oxides significantly increases the strength and durability of cementitious materials [As presented in C618  requirematerials .Table 2C2Natural SCMs are natural pozzolana from the natural sedimentation of volcanic ash or lava that involves active silica, used as cementitious materials when combined with free lime ,170. Hen2.1Bentonite is alumina-siliceous material , mainly C–S–H gel that improves the microstructure and strength of the final hydrated cement matrix, which is mostly dependent on the hydration reaction of pozzolana and cement phase [Employing bentonite improves the strength and durability of concrete in construction works ,210,215.nt phase .Fig. 1SuC–S–H gel in concrete containing bentonite [In addition to these, the mixture of concrete that incorporates bentonite reflects a much denser microstructure compared to the reference mixture . As showentonite .Fig. 3Mi2.2Kaolin is natural pozzolana require calcination to form reactive pozzolana at a temperature between 700 and 1200 °C. So calcined kaolin improves the strength, and durability of Portland cement concrete and other cement composite materials . As presC–S–H) which can improve strength and durability [As shown in rability , and alsrability . Similarrability  as the irability .Fig. 5SuAs presented in 2.3C–S–H gel, it is crucial for the improvement of concrete durability, enhances strength, and lessen the rate of heat liberation important for mass concrete [Volcanic ash is natural pozzolanic material, that occurred during volcanic eruptions when magma or molten rock and solid rock shatter separated form fine particles of clay to the size of sand . As presconcrete . Also adconcrete , and sigconcrete ,243. GenC–S–H gel which significantly improves strength [The employment of volcanic ash actively reacts in cement hydration reactions to form secondary strength . This isstrength ,249.Fig.2.4Zeolite can be used in lime mortar and concrete which is formed from a change of volcanic ash, tuff, and others. It is used in many cement industries over the world as a clinker partial substituent. Most of the effectiveness of zeolite in cementitious material significantly can reduce chloride ion penetration to concrete matrix ,127. ThiC-A-S-H and C–S–H which are crucial compounds to improve the mechanical properties of concrete [Also, the inclusion of zeolite in cementitious materials improves concrete mechanical properties, especially compressive strength, and durability . As presconcrete ,126. Alsconcrete  studied The replacement of cement with natural zeolite reduced the water absorption and chloride diffusion coefficient of concrete . BesidesC–S–H gel that is responsible for making denser microstructure and improve the durability of cementitious materials [Replacement of zeolite to cement ratio is beneficial in enhancing crack width control ability and reduces shrinkage of cementitious materials . As presaterials .Fig. 11M33.1Fly ash is a coal-fired by-product from thermal power plants ,263, maiRaghav et al.  reportedAlso, the replacement of fly ash in ordinary Portland cement with partial replacement has a positive effect on the mechanical and durability properties of cement composites ,269,270,Also, the inclusion of fly ash improves the workability, durability, splitting tensile strength, and compressive strength of cementitious materials . Specifi3.22 in a cement matrix, which is owing to the pozzolanic reaction. Rice husk ash is another biomass ash that is highly reactive pozzolanic material from agro-waste by the combustion of rice husk [Sugarcane Bagasse Ash is biomass ash and a by-product of making juice from sugar cane by crushing the stalks of the plants , that caice husk ,286.C–S–H gel and due to the amorphous state of reactive silica which can significantly enhance the strength and durability of concrete [As presented in concrete .Table 8EEmploying biomass ash mostly improves the compressive and splitting tensile strength of concrete compared to concrete without biomass ash . Mostly As presented in Furthermore, Raghav et al.  reportedBesides improving strength and durability, using biomass ash radically improve the microstructure of cement composites. As presented in Generally, employing biomass ash from agricultural waste ash is beneficial for both technical and economical construction works. Hence it is mostly used for economic construction and for the reduction of environmental pollution .3.3. Employing silica fume in cementitious materials reduces permeability which means increase durability, decreases workability, and improves compressive strength [Silica fume is an artificial pozzolanic admixture  as shownstrength . That is2 by pozzolanic reaction and high pore refinement [As presented in finement . Also infinement ,324 and finement . This isfinement . Besidesfinement . Moreovefinement .Table 9EAs shown in C–S–H) which can improve different properties of cement composite materials. However using of 100% OPC may lack all those important roles of SCMs, since the specific surface area cement is smaller than SCMs and free lime in OPC can not get more chances for the pozzolanic reaction to form additional C–S–H gel. In addition to this, using 100% OPC is costy and have an environmental problem, since its production requires much energy and releases more CO2 to the environment compared to composite cement. But standing on all these benefits of SCMs in cement composite materials, in the practical aspect of construction works can see adding of SCMs materials beyond the researchers result, which may loss all the importance of SCMs in cement composite materials.Generally, from the review of different literature partial substitution of artificial and natural SCMs are beneficial for the improvement of physical, mechanical, durability, and microstructural properties of cement composite materials due to their micro-filling ability, having large surface area and by pozzolanic reaction between the free lime and SCMs to produce secondary calcium silicate hydrate  or calcium aluminate silicate hydrates (C-A-S-H) which can play a great role in the improvement of physical, mechanical, durability, and microstructural properties of cement composite materials.Generally, from most literatures have seen positive effects on the addition of artificial and natural SCMs in cement composite due to active pozzolanic reactions between reactive silica/alumina from SCMs and calcium hydroxide from cement that forms secondary calcium silicate hydrate (5C618 [2), Aluminum oxide (Al2O3), and Iron oxide (Fe2O3) greater than 70%. So it is beneficial to isolately investigate the effect of sulfur dioxide in silica fume can possess on the mechanical, physical, and microstructural properties of cementitious materials. Also, deep investigation is necessary on the durability of silica fume composite cement materials since its observed very limited studies on water absorption and acidic attacks due to silica fume.The most crucial consideration has been seen is that many of the reviewed literatures for the chemical composition of silica fume indicated extremely high silica content which is more than 90%, though ASTM C618  recommenGenerally, it is observed, as there are limited studies on volcanic ash employment on cement composite especially on researching its effect on flexural strength, split tensile strength acidic attack, and microstructure of construction materials, it is crucial to more analyze the effects of volcanic ash on mechanical properties, durability and microstructural change on cement composite.61.As presented in 2.As shown in Although, all the reviewed literatures are important and solved the gap of knowledge concerning artificial and natural SCMs, but the following needs more considerations:All authors listed have significantly contributed to the development and the writing of this article.Data included in article/supp. Material/referenced in article.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


This article describes a dataset with 464 push test results for studs welded within the ribs of profiled steel decking transverse to the supporting beams. The experimental data were collected from 30 publications dated from 1980 to 2017. The dataset presents the measured shear resistance per stud, with over 20 nominal or measured parameters, including: the properties of studs, deck, and concrete; the number of studs within a concrete rib; and the dimensions determining stud position within the concrete rib. This article presents and discusses the statistical parameters of the dataset variables, their distributions, and correlations. The dataset supports the identification of the key design variables that affect the stud shear resistance. It also provides information for evaluating the accuracy and reliability of existing design models, and may be used to form the basis for developing new predictive models. Specifications Table1•The resistance of composite beams in steel-framed buildings depends on the longitudinal shear transfer between the steel beam and the concrete slab through the provision of shear connectors. The most widely used type of shear connector is the headed stud because: the drawn-arc stud welding process is rapid; they provide little obstruction to reinforcement within the concrete slab; and they are equally strong and stiff in shear in all directions normal to the axis of the stud. When studs are welded in steel decking with the ribs transverse to the supporting beams, the shear resistance is reduced.•To account for the presence of the deck slab rib, the resistance has traditionally been determined in many international design standards by multiplying the resistance of a stud embedded within a solid concrete slab by a reduction factor, which has been determined from push tests and accounts for the geometry of the deck in relation to the stud. The existing empirical design models for the stud resistance in deck slabs were developed considering smaller datasets than that presented in the present articule, and do not always produce accurate and safe results.•https://studs-in-deck-slabs.herokuapp.com.The presented data is useful for identifying design variables affecting the stud shear resistance, evaluating the performance of existing design models, and developing new predictive models, as described in ,2 and im•Researchers and practitioners working in the field of composite steel and concrete structures can benefit from the data; in particular, those working on improving design models for stud resistance, and developing national and international design standards.•The data will assist in the identification of underrepresented design parameters, which will be beneficial in extending knowledge in future experimental investigations, and improving design models in terms of their accuracy and reliability.2The dataset The dataset is presented within a Microsoft Excel file in XLSX format with four worksheets. The first worksheet, entitled “Database,” contains the dataset. The second worksheet, “Notes,” provides bibliographic references to the publications used for the dataset collection. The third worksheet, “Diagrams,” presents figures identifying the geometric variables used to describe the deck cross-section, welded stud connectors and the positions of the studs used in the dataset. Finally, the fourth worksheet contains a quality record.Pem, and the following 28 measured parameters:•Nnorm;the normal force on the face of the test slab as a percentage of longitudinal force, •Nribs;the number of ribs per test slab, •nr;the number of studs per rib, •stud position: favorable (F), central (C), unfavorable (U), or staggered (S);•stud welding: through-deck, or holes;•zs;location of reinforcement measured downwards from the top of the stud, •hcs;overall slab thickness including decking, •bslab;width of test slab, •deck name;•t;the thickness of the deck, •deck type: trapezoidal, or re-entrant;•btop;width of the top of the concrete rib, •bbot;width of the bottom of the concrete rib, •b0;concrete rib width, measured at mid-height for a trapezoidal deck or at the top for a re-entrant deck, •hpn;net depth of decking excluding longitudinal stiffener on the crest, •hpg;gross depth of decking including longitudinal stiffener on the crest, •sy;transverse spacing between studs within rib, •sx;longitudinal spacing between studs within rib, •e;longitudinal distance from the stud centre to the deck web at the trapezoidal deck mid-height or the re-entrant deck top, •et;longitudinal distance from the rib top corner to the nearest stud centre, •fcm;concrete compressive strength, •Ecm;concrete secant modulus of elasticity, •fum;ultimate tensile strength of studs, •fypm;yield strength of decking, •dm;diameter of stud shank, •ddom;weld collar diameter, •hwm;weld collar height, •hscm; andstud height after welding, •hscm/dm.the stud height-to-diameter ratio, The dataset includes the mean measured shear resistance per stud, •fck, in accordance with EN 1992-1-1 the characteristic compressive cylinder strength, •Ecm, calculated from fck in accordance with EN 1992-1-1 concrete secant modulus of elasticity, •fu, in accordance with EN ISO 13918 ultimate tensile strength of studs, •fyp;yield strength of decking, •d;stud shank diameter, •ddo;weld collar diameter, •hw;weld collar height, •hsc/d; andthe stud height-to-diameter ratio, •hsc.specified as-welded stud height, The following nominal properties required for reliability analyses in accordance with the Eurocodes are also presented in the dataset:fcm, was reported in the publications for different cube and cylinder specimens cured at different conditions. It was converted into the cylinder strength as described in Ecm, was not reported, it was computed based on fcm in accordance with the fib Model Code 2010 ddom, and height, hwm, were taken from EN ISO 13918 fck according to the strength classes given in EN 206 The measured concrete compressive strength, 3The dataset was collected from 30 publications, dating from 1980 to 2017, which describe push tests on studs welded within the ribs of profiled steel decking transverse to the supporting beams. The publications included in the database were identified through an extensive literature survey, and included tests that were considered in the original calibration of Eurocode 4 ,11. The 4None.The authors declare that they have followed the general ethics rules of scientific research performance and publishing. This work did not involve human subjects, animal experiments, or data collected from social media platforms.Stephen J. Hicks: Conceptualization, Methodology, Validation, Investigation, Data curation, Writing – review & editing, Supervision. Vitaliy V. Degtyarev: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Writing – original draft, Writing – review & editing, Visualization.


Umbrella Sampling Molecular Dynamics has been used to determine transition energies for different guest molecules through hydroquinone  A clathrate is a solid structure whose constituent molecules, known as hosts, are arranged in an ordered and periodic lattice such that small guest particles can fit between the voids or cells of the network, thus becoming encapsulated within the matrix. The types of occupancy that can occur within the same cell are divided into single or multiple, depending on whether there are only one or more guests per cavity within the crystalline structure, and these can cross from one cell to another in a slow diffusion process in which a specific energy difference comes into play at each transition. This energy is dependent on the characteristics of the guest molecule. For the same host structure and at similar pressure and temperature conditions, the diffusion potential energy barrier is guest dependent. Understanding the specific diffusion process of each guest within a clathrate can help to extend the increasing applicability of these compounds, as well as being directly related to climate change processes, which are currently very relevant on our planet.The first record of these compounds dates back to the 19th century, described in laboratory conditions by prominent scientists such as, for instance, Faraday ,3. TheseScientific and industrial interest in such compounds was later stimulated by the discovery of large quantities of methane hydrate in continental permafrost and on the ocean floor, which might appear to be an energy resource to be considered in the first instance ,6. Howevnditions ,6, a dre00 years ,9,10,11.The consequences of increased atmospheric concentrations of these gases are known to result in a redistribution of the planet’s desert and wetland areas. These changes have been directly linked to an imbalance in the number of pests and diseases affecting flora and fauna alike, including human health ,13,14. TIn parallel to the water-based host structure, organic clathrates offer a wide variety of solid matrices with unique characteristics and distinctive properties. A clear example of a competitive structure from an applied point of view is hydroquinone clathrate (HQ clathrate) ,17,18, tThe HQ-based solid and crystalline matrix can act selectively towards moderately complex combinations of gaseous substances, being able to discriminate between them. HQ clathrate has a high affinity towards COse gases ,27.In addition, it is worth highlighting the high adaptability of the structure of HQ, which allows the safe storage of substances inside it, some of such importance for current human development as hydrogen ,18,22,23Regarding the different phases of HQ solid crystalline phase, three different polymorphs can be distinguished that can occur under normal conditions: β, and γ ,28,29. Te phases ,28,29. Wing them ,31,32. Tthem [3¯ ,33. In tP3 group ,32,33. Ithe same ,34. It ie δ form ,31,32. TThe typical diffusion process of any guest within the nanoporous structure of However, although all possible guests for a structure have both types of motion within the As a feasible solution to this problem, several alternatives have been proposed to correct the poor sampling in the simulated production phase. Among them is a method known as “Umbrella Sampling”, which was chosen for this study due to its compatible properties, thus providing an alternative approach to the study of the problem of interest ,37,38,39In contrast to the great advantages that the Umbrella Sampling technique offers, it requires working on a previously defined trajectory, which implies ignoring possible relevant configurations that may occur outside the previously imposed reaction coordinate, with possible repercussions on the macrostate. In the system formed by the HQ clathrate and several guest particles, there is the possibility of a transit of some of them to one of the so-called “secondary channels”, in which the guest is placed outside the primary channel that originally contained it and, therefore, away from the typical trajectory taken into account by the method. However, the probability associated with this event is very low for situations of multiple occupancy of the network, and is almost completely negligible in single occupancy conditions, as discussed in this paper. Consequently, the Umbrella Sampling technique is a convenient and useful option whose characteristics are remarkably suited to those required, providing the necessary tools to address the objective of this study.Simulations were performed using classical Molecular Dynamics, based on the OPLS-AA  forcefield ,40. Diffus study , the metBesides these models representing real gases, theoretical guests were also built for different values of Lennard–Jones parameters, x equivalent to y and different from z. Usual periodic boundary conditions and minimum image conventions were considered. Cut-off values for long-range interactions were set to 1.4 nm. The calculation of intermolecular interactions was accelerated using Particle Mesh Ewald (PME) algorithm [Velocity re-scaling thermostat  was empllgorithm ,46, and lgorithm  were useThe Umbrella Sampling (US) method was used as cited to overcome the limitations of the conventional MD simulations in the description of low-probability events. The method WHAM   was usedent work , where iGromacs ,51,52, vThe initial topology for the fraction . The newThis procedure has been replicated for each of the calculations for a total of 11 different Lennard–Jones fluids, in a temperature range varying from 220 K to 400 K at 20 K intervals. For the sake of simplicity, these two new types of theoretical guest have been divided into two distinct groups, those named “E” followed by their corresponding number being those where the same value of Given the impossibility of repeating in triplicate each of the calculations due to the large number of simulations involved, an indicative overall sampling standard deviation is obtained for the dataset for a single guest under identical conditions. The temperature trend of the transition energies for the group “E” guests is shown in From a physical perspective, the observed effect can be explained through the definition of The specific results obtained with the Umbrella Sampling technique for the The results obtained can be considered consistent, and follow logical and predictable progressions, with fitting uncertainties reasonable and acceptable together with high correlation coefficients. However, the values obtained for the guest “S2” deserve comment, presenting low rFrom the combination of the general set of equations obtained from the fits, it is possible to construct a general and predictive expression capable of yielding an interpolated To test the fit from the two different sets of proposed Lennard–Jones theoretical fluids, a similar procedure has been carried out for different guests whose characteristic Lennard–Jones values, collected and related to their respective guest in the aforementioned The results obtained show that the larger errors are associated with the configurations at low temperatures. At these conditions the energy levels of the key configurations of the system at the transition between cells are farther apart and, therefore, the sampling must overcome a higher potential barrier, making it more difficult to obtain representative energy sampling. This effect can be easily observed for hosts such as Ne, F, or HAn underestimation is also observed of the correlated He values, compared to those obtained directly from the Umbrella Sampling technique. This may be due to poor sampling occasionally observed in particles whose transit energy is consistently low, causing their hopping between neighboring cells to become spontaneous and observable with conventional Molecular Simulation times. Consequently, the particle traverses those areas crucial for the proper description of the energy landscape along the reaction coordinate Considering the specific case of HFor the particular o et al. . ExperimThe variation in the transition energy between HQ clathrate cells at different temperatures of a group of guest substances made up of Lennard–Jones fluids has been computed using the Umbrella Sampling technique. To analyze the influence of the guest characteristic Lennard–Jones parameters, two sets of theoretical guest molecules were explored: “E”, those whose progression keeps the value of A similar process has been repeated at different temperatures within the proposed range for different realistic guest particles able to emulate the real behavior of their respective fluid from Molecular Simulation methods, these being: He, Ne, F, HThus, the method applied in this work can be used in a broader context to estimate different gas diffusion properties inside solid materials. As shown by the results presented here, the Umbrella Sampling theoretical approach can describe with accuracy even low-probability transition phenomena for this type of system, revealing itself as a valuable tool to explore processes, such as solubility or permeability, just to cite a couple of representative and interesting examples.


Biochar has shown great promise in producing low-cost low-carbon concrete for civil infrastructure applications. However, there is limited research comparing the use of pristine and contaminated biochar in concrete. This paper presents comprehensive laboratory experiments and three-dimensional nonlinear finite element analysis on the mechanical, economical, and environmental performance of reinforced concrete beams made using concrete blended with biochar generated from vetiver grass roots after the roots were used in an oil extraction process. Both pristine biochar and biochar that were used to treat wastewater through adsorbing heavy metals  were investigated. The biochar was used to replace up to 6% Portland cement in concrete. Laboratory experiments were conducted to characterize the workability, mechanical properties, shrinkage, and leaching potential of the concrete blended with biochar. The results showed that using biochar could increase the compressive strengths and reduce the shrinkage of concrete without causing a leaching problem. The results from finite element analysis of the reinforced concrete beams showed that the use of biochar was able to increase the flexural performance of the beams as well as their economic and environmental performance. This research will promote the development and structural applications of low-cost low-carbon concrete. The manufacturing of cement accounts for about 8% of global emissions caused by humans [Concrete is the most widely used construction material worldwide because of its low cost, ease of use, and local availability . ConcretPrevious research showed that it is promising to valorize various types of waste to produce such materials to amend with concrete for structural applications. The widely used types of solid waste include industrial by-products  to evaluate the efficiency of the vetiver root biochar in removing heavy metals in an aqueous media; (2) to evaluate the workability, compressive strengths, shrinkage, and leaching potential of concrete blended with biochar; (3) to understand the underlying mechanisms of the effect of biochar on concrete properties; and (4) to evaluate the mechanical, economic, and environmental performance of reinforced concrete made using the developed concrete with biochar.These research objectives reflect the intellectual merits of this research, which generates new knowledge about the employment of biochar on the constructional, mechanical, economic, and environmental performance of reinforced concrete. Regarding the broader impacts, the knowledge generated from this research will promote the valorization of various types of waste in producing low-carbon cost-effective concrete for structural applications, which will, on one hand, reduce the carbon footprint and cost of the construction industry, and on the other hand, minimize the landfill of waste and the environmental impact such as leaching of heavy metals from waste.To achieve the above research objectives, this research conducted comprehensive laboratory experiments on biochar and biochar-modified concrete to investigate the effects of both pristine and heavy metal-contaminated biochar on the fresh and hardened properties as well as the leaching potential of concrete and performed finite element analysis to understand the effects of biochar on the mechanical, and environmental performance of reinforced concrete.The remainder of the paper is organized as follows: This section provides an overview of the methods, as shown in 2 gas at a flow rate of 0.1 mL/min.The biochar used in this research was generated from the roots of vetiver, which is a type of lignocellulosic, perennial, warm-season (or C4) grass with high efficiency at carbon sequestration for its dense root system with its roots having a high commercial value in the aromatherapy and perfumery industry . After t2 silicon drift detector .This research characterized the bulk density, yield, surface area, pH, electric conductivity, and cation exchange capacity as well as the physical and chemical properties of the biochar. The total elemental analysis for inorganics was performed following a standard method recommended by the Environmental Protection Agency (EPA) of the USA with a few minor modifications . An elem−1 and 4000 cm−1. Sample pellets were made for all samples using fused-KBr at a 100:1 KBr:Biochar ratio for transmission studies. An average of 100 scans at a resolution of 4 cm−1 were performed for each sample. The spectra were examined using commercial software, called OMNIC .The surface chemical properties were determined via Fourier transform infrared spectroscopy using an FTIR spectrometer  with spectra collected between 400 cm2+, Cd2+, Pb2+, and Zn2+ were prepared using Cu(NO3)2·3H2O , Cd(NO3)2·4H2O , Pb(NO3)2 , and Zn(NO3)2·6H2O  salts, which were dissolved in deionized water. A solution of 0.1 M sodium nitrate (NaNO3) was added to the solutions to provide ionic strength. The temperature was controlled at 24 ± 2 °C, and 100 mg/L of each metal concentration was adsorbed onto 10 g biochar (1% w/v) in a 1 L solution for 24 h. Several batches were prepared to obtain the desired quantity of contaminated biochar. The initial and final concentrations of the solution were recorded. The removal percentage of heavy metals was calculated by Equation (1) [0 and Ce are the initial and the final concentrations of the solution, respectively.The biochar was used to conduct batch adsorption tests for four heavy metals, which are Cadmium (Cd), Copper (Cu), Lead (Pb), and Zinc (Zn). These heavy metals are representative of stormwater runoff from different sources and wastewater. The solutions of Cution (1) :Removal The mixture design of concrete blended with biochar is listed in The particle size gradation of the cement and the sand used in the cement mixture is shown in A Hobart HL200 mixer was used to prepare concrete in three steps: (1) the dry ingredients  were introduced to the mixer and mixed at 107 revolutions per minute (RPM) for 2 min. (2) The HRWR was dissolved in 90% mixing water and gradually added to the mixer within 1 min. (3) The mixture was mixed at 107 RPM for 3 min.The concrete was poured into standard molds in triplicates, including cubic molds that measure 50 mm × 50 mm × 50 mm and prism molds that measure 280 mm × 25 mm × 25 mm in dimensions. The cube specimens were used to test the compressive strengths, and the prism specimens were used to test the shrinkage. During the casting of concrete, the molds were placed on a vibrating table to ensure consolidation of concrete. Immediately after the casting, the specimens were wrapped with polythene sheets and then stored in a controlled environment at 25 °C and 70% relative humidity for 24 h. After that, the specimens were cured in lime-saturated water at 25 ± 2 °C until the date of testing. All the results characterizing the concrete performance were the mean values of triplicates. In addition, after the mixing process, all concrete mixtures were examined by hand, and no agglomeration or segregation was found.The workability of the concrete was evaluated according to ASTM C143 . SpecifiThe compressive strengths of concrete at 7 days and 28 days were evaluated using the cube specimens according to ASTM C109 . The loaThe evolution of the heat of cement hydration was evaluated using an isothermal calorimeter , which was programmed to maintain the samples at 25 °C. About 60 g of fresh concrete was sealed in a plastic vial and placed into the calorimeter. The measurement of the heat of hydration started 2 min after the end of mixing and continued for 36 h. The results were normalized by the mass of the cement.The autogenous shrinkage of concrete was evaluated in accordance with ASTM C1698 . The finThe Synthetic Precipitation Leaching Procedure (SPLP) method recommended by US EPA as a batch leaching test was used to evaluate the risk of heavy metals . The pH The leachability of the trace elements from concrete to determine if it is hazardous was assessed according to the Toxicity Characteristic Leaching Procedure (TCLP) recommended by EPA . A pieceProgressive TCLP tests were performed to investigate the behaviors of metal pollutants that leached from the concrete . There w2 > 0.995 were attained before each study. Three replicated measurements were prepared for each sample. ICP Expert Software (v7.1.0.6821) was used to operate and process the ICP-OES data . All the containers were cleaned with laboratory-grade detergent, steeped in 10% nitric acid solution for 12 h, soaked in deionized water for 6 h, and rinsed with deionized water. The Tukey–Kramer honestly significant difference (HSD) test was performed to assess significant differences (p < 0.05) using the Origin software (v2022b) [Certified reference solutions were checked beside the samples. Both internal and external standards were examined in every ICP-OES analysis. To calibrate the system, standard solutions with R(v2022b) .The flexural behaviors of reinforced concrete beams made using the concrete with biochar were investigated via 3D finite element analysis using software called ABAQUS 2017. The methods used to establish the finite element model were developed in previous research ,41. The The boundary conditions of the beams were defined as follows: (1) in the symmetrical plane at the mid-span section, the displacement along the length direction is zero. (2) In the symmetrical plane at the mid-width section, the displacement along the width direction is zero. (3) Along the lines over the rollers, the displacement along the vertical direction is zero. The vertical loads were applied to the beam under the displacement control mode. The study utilized the embedded region constraint in the software ABAQUS 2017 to model the interaction between concrete and steel reinforcement by using the keyword “embed”, meaning that debonding was not considered. This method has been widely employed in finite element analysis on the behavior of reinforced concrete structures ,45,46,473 and 0.2, respectively. The density and Poisson’s ratio of steel bars were 7800 kg/m3 and 0.3, respectively. The yielding strengths of the steel bars were related to their diameters. The yielding strengths of the steel bars with diameters 6 mm, 16 mm, and 22 mm were 420 MPa, 445 MPa, and 430 MPa, respectively. The elastic modulus of steel bars was 205 GPa. These material properties are consistent with previous research on experiments and finite element analysis of the flexural behaviors of reinforced concrete [The density and Poisson’s ratio of concrete were 2600 kg/mconcrete .The concrete damage plasticity model was applied to consider the damage in concrete during the loading process. More detailed information about the concrete damage plasticity model is available in references ,50 and i2/g. The pH was about 11. This biochar had a high carbon concentration. According to the acid digestion method [The physicochemical characteristics of the biochar are listed in n method , the bion method .The efficiency of using biochar in removing heavy metals through multi-metal batch adsorption experiments is shown in The effect of biochar contents on the workability of fresh concrete mixtures is shown in In this research, the biochar was not pre-soaked because pre-soaking biochar with additional water would increase the total water content and, thus, the water-to-cement ratio of the concrete mixtures. It is known that the increase in the water-to-cement ratio tends to reduce the mechanical strength and durability of concrete. In practice, if the workability is sufficient for construction, it is often effective to increase the HRWR content . The tesThe compressive strengths of the concrete mixtures at 7 days and 28 days are shown in Such results are caused by two competing effects. On one hand, biochar provides filler effects to increase the compressive strength of concrete. On the other hand, biochar introduces defects such as pores and interfacial transition zones to decrease the compressive strength of concrete. When the biochar content was lower than 2%, the filler effect was dominant. When the biochar content was higher than 2%, the weakening effects became dominant. These results are consistent with previous research ,58. The The results of the heat of hydration are shown in According to reference , the hydIn this study, the roots were pyrolyzed at 500 °C for 60 min to produce biochar. The cellulose and hemicellulose were decomposed during the production process to retard the cement hydration. Moreover, the dry biochar powder without pre-soak treatment was directly used in this study. Since the mechanical strengths of concrete are gained through the hydration reactions, the results of the heat of hydration explain why the excessive addition of biochar reduced the compressive strengths of concrete. The results also show that the presence of heavy metals further retarded the hydration reactions of cement, thus further reducing the compressive strengths of concrete.The results of the autogenous shrinkage of the investigated concrete mixtures are shown in There are two main underlying mechanisms: (1) porous biochar particles absorbed water and released the internal curing water during the hardening process to delay the drop of the internal relative humidity inside the concrete, thus reducing the autogenous shrinkage. (2) The biochar retarded the hydration of cement, thus alleviating the autogenous shrinkage.The concentrations of the heavy metals in the leachates from the SPLP test are listed in The concentrations of the heavy metals in the leachates from the standard TCLP test are listed in The concentrations of the heavy metals of the progressive TCLP test are listed in The pH values of the leachate in the progressive TCLP test are plotted in The differences in peak load between Beams 1, 4, and 5 were small. For instance, the difference in peak load between Beams 4 and 5 was 4 MPa. Given the vertical axis in Previous studies revealed that the biochar addition does not significantly alter the modulus of elasticity of mortar ,61. For The cracks in the concrete are quantitatively represented by a tension damage index, which is denoted by DAMAGET. DAMAGET is in the range of 0 to 1: 0 means there is no tension damage , and 1 means the concrete is completely cracked. The workability of concrete is relevant to the construction quality as poor workability often causes problems with the placement and consolidation of concrete in the construction of structures such as bridges and buildings . The reaThe results of finite element analysis show that utilizing biochar can improve the mechanical performance of the investigated beams. The results of energy dissipation of the investigated beams are shown in M is the unit cost of a concrete mixture per cubic meter (unit: $/m3); im is the unit cost (unit: $/kg) of the ith ingredient of the mixture , as listed in ir is the mass of the ith ingredient of the mixture (unit: kg/m3), as listed in C is the carbon footprint of a concrete mixture; ic is the unit carbon emission of the ith ingredient of the mixture , as listed in ir is the mass of the ith ingredient of the mixture, as listed in The economic and environmental performance of the beams were evaluated using the data in The calculation results are plotted in The use of biochar was able to increase the compressive strength of concrete. When biochar was used to replace 2% of Portland cement in the concrete, the compressive strengths of the concrete were increased. When the replacement percentage was higher than 2%, the use of biochar reduced the compressive strengths of concrete. Compared with pristine biochar, the contamination of biochar by heavy metals reduced the compressive strengths due to the delay of hydration of cement.The use of biochar decreased the shrinkage of concrete. When the biochar was used to replace 6% of Portland cement in the concrete, the autogenous shrinkage of concrete was reduced from 264 µε to 112 µε. The main mechanism was the internal curing effect of porous biochar. Compared with pristine biochar, the contamination of biochar by heavy metals reduced the autogenous shrinkage due to the delay of hydration of cement.The use of biochar decreased the workability of concrete. When biochar was used to replace 6% of Portland cement in the concrete, the slump of the concrete was reduced from 135 mm to 103 mm. The main mechanism was the water absorption effect of porous biochar. Compared with pristine biochar, the contamination of biochar by heavy metals did not affect the workability of concrete.The use of biochar in concrete did not cause a leaching problem. The concentrations of the heavy metals were well below the EPA limits, indicating that the biochar that was used to absorb heavy metals was not a hazardous waste. In other words, it is promising to use biochar to immobilize the heavy metals and then produce cost-effective eco-friendly concrete.The use of concrete blended with biochar was able to improve the mechanical properties, economic, and environmental performance of reinforced concrete beams. Using concrete with different biochar contents in layers was able to further improve the economic and environmental performance of reinforced concrete beams while retaining the flexural properties of the beams.This study investigates the effects of using biochar in low-cost low-carbon concrete on the mechanical, economic, and environmental performance of reinforced concrete beams through comprehensive laboratory experiments of the concrete and finite element analysis of the reinforced concrete beams. The following conclusions can be drawn from the above investigations:Future research is needed to understand the influence of contaminated biochar on the durability of concrete and reinforced concrete beams. It is also important to evaluate the effect of biochar on the demand for water reducers to ensure adequate flowability and constructional performance.


Traditional ecological restoration technology has many challenges in dealing with the greening of steep rock slopes, especially in the case of serious soil erosion. In order to overcome these problems, this study aims to organically combine the traditional protection and reinforcement technology with the new vegetation restoration technology, and put forward a new ecological protection technology of composite vegetation concrete to realize the comprehensive protection and ecological restoration of rocky slopes. In this paper, by analyzing the mechanism and existing problems of ecological protection of rocky slopes, the design requirements of composite vegetation concrete are studied in detail, and the related construction technology is expounded. In the experiment, the vegetation coverage and incidence were systematically analyzed, and the results showed that some samples showed high vegetation coverage and low incidence. Comprehensive consideration shows that the average vegetation coverage rate is 93.7%, and the average incidence rate is only 5.21%, which all meet the corresponding standards. The composite vegetation concrete technology has a wide application prospect in stone slope protection, which significantly improves the slope vegetation coverage and compressive strength, and effectively promotes the slope greening and ecological sustainable development. Through this study, we aim to convey to readers that the comprehensive method of combining traditional and innovative technologies can achieve encouraging results in solving the problem of ecological restoration of steep rock slopes, and provide useful reference for engineering practice in similar environments. Engineering machinery can truly achieve the perfect combination of side slope support and greening functions by utilizing existing equipment. Therefore, this article explores the construction methods of composite vegetation concrete in side slope protection.The composite vegetation concrete ecological protection technology is a new technology that utilizes special concrete formulas and seeds to protect and green mountain slopes. The composite vegetation concrete material has a wide range of raw materials, which not only reduces the construction difficulty, but also ensures the operability principle of side slope protection engineering and the overall effect of greening side slope management. Meanwhile, it solves the shortcomings of traditional side slope protection methods, such as anchor brackets, original paint brackets, support walls, etc., which cannot be used for green side slope support. Composite vegetation concrete materials have excellent corrosion resistance and simple production process2. Othman explored the possible success and failure factors of slope protection methods through side slope stability analysis, to determine potential side slope protection schemes for the Sengarang coastal embankment3. Nishiwaki further classified the types of side slope protection methods based on rock types or geological time scales from the perspective of representative side slope farmland selected from a hundred selected slope farmland in Japan4. Lee discussed the use of alkaline cation crosslinking method of calcium hydroxide and sodium hydroxide to induce non thermal gelation and implemented the site soil with the best performance in the indoor assessment on the site side slope of the abutment5. Chun analyzed the main factors of side slope deformation based on the engineering geological conditions and surrounding environment of ancient mining relics and used a deep sliding force monitoring system to continuously monitor the side slope stability of the relics6. Liao conducted a case study on airport runway side slopes to provide an optimized design scheme for reinforced soil side slopes with high fill side slopes7. Xu systematically explored the impact of local rainy season heavy rainfall on the vast soil side slopes protected by retroviruses in Nanning through in situ comprehensive monitoring and comparative analysis8. Fu reviewed the latest research progress in ecological protection technology, identified the main construction processes and types, revealed the protection mechanism of ecological protection technology and analyzed the comprehensive benefits of ecological side slope protection technology9. Slope stability protection is to reduce the damage caused by soil erosion, landslide and collapse, and protect land, infrastructure and environment. Vegetation cover, plant root system reinforcement and slope protection net are all common slope stability protection methods. In summary, side slope ecological protection can improve the soil environment of the side slope and increase the vegetation coverage of the side slope soil. However, further research is needed on the application of composite vegetation concrete.The protection of side slopes is often difficult to construct, with low operability and slow effectiveness. Research on side slope protection helps to find new methods to solve these problems and improve its governance effectiveness. Chi introduced an innovative spiral anchor for horizontal drainage ditches, which was an underground drainage system used for side slope protection10. Wang explored the similarities and differences in water transport between vegetation concrete and natural soil and found that vegetation concrete could improve the growth effect of plants in side slopes, providing theoretical reference for the irrigation layout and irrigation schedule of soil drip irrigation systems under the ecological restoration of high and steep side slopes11. To quantitatively evaluate the erosion resistance of vegetation concrete, which was a typical artificial composite soil, Zhou compared it with natural soil under the same site conditions in the laboratory and determined and calculated the distribution characteristics of aggregate particle size and the protective effect of vegetation concrete on side slopes12. In summary, vegetation concrete can significantly improve the growth effect of plants in side slopes, which is of great significance for ecological protection of side slopes.Vegetation concrete has excellent protective effects in side slope engineering and many scholars have analyzed the application of vegetation concrete in side slopes. Ye applied the wet spraying vegetation concrete ecological side slope protection technology to the side slope protection project of Huama Lake water system connecting channel in Ezhou City, Hubei Province and observed the side slope protection and water and soil conservation effects, plant coverage, plant density, average plant height and species diversity indicators on siteComposite vegetation concrete is mainly used for greening and protection of stone side slopes. To study the specific application effect of composite vegetation concrete in side slope protection, this article studies the spraying thickness of vegetation concrete in side slope protection and analyzes the spraying thickness under different side slope gradients. In the relevant experimental section, the porosity and pH of the spray layer in side slope protection are studied and it is found that the porosity and pH of the composite vegetation concrete are qualified. Besides, the plant growth rate of side slope protection engineering under composite vegetation concrete has significantly improved and the overall coverage rate of plants has also reached the qualified standard.13. Perhaps if there is a certain gap at the bottom of the side slope, then under the action of small external forces , the side slope experiences instability. In terms of physical properties of composite vegetation concrete, it needs to have good moisture resistance and light resistance and a unit weight of 14–15 kN/m3. The porosity is between 30 and 45%. In terms of the mechanical properties of composite vegetation concrete, the strength tested in situ is: 1 month, 0.29 MPa; within three months, 0.38 MPa; 1 year later, 0.42 MPa; two years later, 0.40 MPa; three years later, 0.39 MPa. During the construction of composite vegetation concrete, mesh reinforcement is adopted. Meanwhile, plants planted on the side slope can also effectively resist rainstorm scouring, sun exposure, temperature changes and so on14. Besides, its anti-seepage performance is designed based on an average annual precipitation of 2000 ml. In the use of composite vegetation concrete, it is found that the seed germination rate is 90% and the vegetation coverage is 95%. The soil fertility is good and the seed growth status is good.The carbon sources required by rhizosphere soil microorganisms in side slopes are mostly composed of sugar water compounds, amino acids and polymers15. The same type of composite vegetation concrete, when used in different projects, plays a different role. Therefore, the appropriate mix proportion should be selected based on the actual situation for composite vegetation concrete. The composite concrete side slope protection composed of concrete beams and rock fillers can reduce the overall thickness of the required protective cover16. The composite vegetation concrete side slope protection structure is a new type of side slope protection structure. The raw material ratio of composite plant concrete should follow targeted formulas and production principles, so that the formula of composite plant concrete can maximize its function and achieve the maximum effect of side slope protection and greening. The formula and required functions of composite vegetation concrete used in side slope ecological protection are shown in Table The height of high and steep side slopes usually exceeds 30 m and some side slopes do not have raceways. Regardless of the construction measures used, their construction management is very difficultUsually, sandy loam soil with medium particle size and good three-phase ratio is chosen. The water and fertilizer conditions are good and suitable for plant growth. In composite vegetation concrete, sandy loam is the most important component. At present, measures such as sand molding and adhesive molding have been adopted in side slope protection, but to ensure the healthy growth of plants, it is usually necessary to combine other types of measures for improvement.17. Cement, as the main bonding component of composite vegetation concrete, is usually selected as ordinary Portland cement with a requirement for the alkalinity of its clinker not exceeding 0.6%. In the reduction of pH value in composite vegetation concrete, additives such as Portland cement and limestone are used to reduce its pH. After hydration, a mixed vegetation concrete reinforced by a spray layer can be formed, which has a certain strength and can resist rain erosion. The amount of cement added is influenced by the soil pH value, usually ranging from 5 to 12%. If it is too low, it cannot achieve reinforcement effect. If it is too high, it may cause high alkali content, which is unfavorable for plant growth and uneconomical.Cement has many superior properties and is widely used for side slope protection in civil engineeringIn the selection of organic matter for composite vegetation concrete, using fresh rice husks and wood chips, as well as adding decayed rice husks and wood chips as organic matter, can improve its three-phase and water holding properties. Rotten rice husks and sawdust inject a large amount of microorganisms into the composite vegetation concrete. They work together with the plant roots to gradually transform the composite vegetation concrete into soil suitable for plant growth and provide it with certain nutrients such as nitrogen, phosphorus and potassium. Besides, crushed straw can also be used to replace wood chips and rice husks.In the selection of fertilizers, it is better to combine long term fertilizers with short term fertilizers. Short term fertilizers can promote short-term growth of plants, while long term fertilizers aim to prevent long term degradation of plants.A series of water retaining agents are used in ecological protection of side slopes: starch series, cellulose series, synthetic polymer series, protein series, other natural product and their derivatives series, mixed series, etc. However, from the perspective of cost-effectiveness, water absorbing resins are commonly used in engineering, which can significantly improve the drought resistance of composite vegetation concrete.In the selection of grass seed formula for composite vegetation concrete, it is suggested to try to choose imported industrialized grass and shrub seeds and use multiple grass seeds at the same time. In the spraying of composite vegetation concrete, it is necessary to have grass seeds in the upper layer and no grass seeds in the lower layer.Acid alkali buffering agents, dyes, disinfectants and particulate matter are essential additives in vegetation concrete, which can regulate certain characteristics of composite concrete to stimulate plant growth. For example, adding phosphate plates to flammable industrial waste may have different functions, such as recycling, pH control and improving productivity.The steps of ecological protection of rocky slopes include selecting and matching plant varieties according to slope types and average annual rainfall, thoroughly cleaning rock slopes, gravels and soil of rock slopes, fixing anchor rods, laying iron-zinc nets, preparing composite plant concrete, carrying out high-pressure spraying, and carrying out maintenance and management in the later period.In the ecological protection of stone side slopes, corresponding protective measures need to be taken according to the specific situation of the stone side slope, as shown in Table The type of side slope, annual rainfall (duration of drought days) and side slope have a significant impact on the thickness of composite plant concrete spraying. Because the composite vegetation concrete side slope protection and greening technology is mainly applied to stone side slopes and the side slope is usually large and the soil formation speed is lower than the erosion speed, the thickness of the spraying cannot be too small. However, from an economic perspective, it cannot exceed 10 cm. The specific spraying thickness is shown in Table According to Table The factor that affects the spraying thickness is also the side slope gradient, so it is necessary to analyze the spraying thickness of composite vegetation concrete under different gradients. Seven types of side slopes were investigated and their gradients from small to large were stone side slope 1, stone side slope 2, stone side slope 3, stone side slope 4, stone side slope 5, stone side slope 6 and stone side slope 7. The specific spraying thickness is shown in Fig. 18. Under steep slope conditions, water in the soil was easily lost and difficult to store in the soil, seriously affecting the growth of plants in the soil. Therefore, the size of the side slope gradient was closely related to the spraying thickness and the spraying thickness of composite vegetation concrete should be correspondingly increased to improve water conditions and ensure the vegetation growth conditions of the soil. For stable slopes, the compressive strength of the composite concrete plant frame was about 10 MPa.In Fig. Plant species have a direct impact on the effectiveness and lifespan of composite vegetation concrete technology. When adopting the ecological side slope protection technology of composite vegetation concrete, the first issue to be paid attention to is the selection and combination of plant species, which must be adapted to the local environment and able to provide sufficient nutrition and water for the vegetation. Trying to choose local plants in the area where the side slope road is located, they are scientifically configured to form the optimal plant community and build a scientific ecosystem. When selecting composite vegetation concrete, the following requirements should be met: adapting to local climate conditions, local types are used as much as possible, achieving diversity of types. The seed germination speed is fast, while the germination rate is high and it has strong drought resistance ability. Combining cold and warm grass seeds can achieve good greening effects. Moreover, after determining the plant variety, a germination test must be conducted with a germination rate of over 95% before subsequent construction can proceed. Based on the specific ecological situation of the side slope, plants with certain cold and drought resistance abilities such as Agropyron cristatum, Medicago sativa, Amorpha fruticosa, Lespedeza bicolor, Caragana korshinskii, Cosmos bipinnatus  and Siberian Elm are selected under low precipitation conditions. Woody plants often choose local tree species and some tree species that are resistant to drought and have strong nitrogen fixation. In cases where the side slope is broken and has many cracks, shrubs can be added to the side slope. For steep slopes with intact rocks, shrubs may not be planted.After selecting plants, it is necessary to start by completely cleaning the rock side slope, gravel and rock slope soil. It is necessary to clean up dangerous rocks. If the protrusion is strong, tools should be used to adjust the prediction to remove about 50 cm of silt and various joint side slopes, to facilitate the smooth operation of the anchor chain in the future.In this protection, 12 mm threaded steel bars are selected approximately, arranging a spacing of 1 m × 1 m and selecting a length of 45-65 cm. When anchoring, a hammer can be used to impact it to a depth of 40 cm. During the drilling process, it is necessary to ensure that the hole diameter is 12 mm and that the drilling direction is perpendicular to the slope direction.In this type of protection, the steel wire mesh used is a diamond mesh of size 4, with a mesh size of 5 cm × 5 cm. In actual paving operations, the distance from the top of the slope is approximately 50 cm. It completely covers the rock side slope from top to bottom. For adjacent mesh holes, parallel docking can also be used to tighten the joints of the mesh holes to form a complete mesh.According to the actual situation of the side slope, slight adjustments have been made to the cement and additives. Composite vegetation concrete can be divided into two types: the foundation layer and the surface layer. Usually, it is not necessary to add grass seeds to the cement foundation layer. Grass seeds are added on the surface layer, which is convenient to save costs and improve the survival rate of grass seeds. During specific construction, the foundation concrete and surface concrete should be prepared separately and a vertical mixer should be selected for mixing.Air compressor is selected to conduct high-pressure spray seeding for composite vegetation concrete. The traditional anchor spraying machine should be used from top to bottom, with a thickness of 10–12 cm. Spraying is carried out in two stages, first spraying a base layer of 8–10 cm and then spraying a surface layer of 1–2 cm thick. After high-pressure spraying, composite plant concrete must be cured immediately.In the proportion of composite vegetation concrete, more consideration should be given to local materials in terms of raw materials to cost reduction and targeted selection of various plants should be combined with the climate characteristics of the project site. The maintenance work of composite vegetation concrete mainly includes three aspects: moisture, fertilizer and prevention of diseases and pests. Firstly, in the germination stage of composite vegetation concrete seeds, it is necessary to control the amount of water sprayed and prevent the water column from directly entering the plant body. Otherwise, it can cause a significant impact on the plant and affect its growth. In high temperatures, plants should not be watered to avoid burning them. Secondly, regular fertilization and sowing should be carried out to ensure that plant seeds receive sufficient nutrition and fertilization should be carried out according to the specific conditions of the plant seeds. Thirdly, the control of pests and diseases is mainly aimed at some common pests, using physical and chemical methods to control them as little as possible to harm the plants and ensure their normal growth.Plants can only grow under specific conditions. In the design of porosity required for plant growth, when the porosity is greater than 20%, it can meet the porosity required for plant growth. Moreover, the larger the porosity, the better the growth of the plant. However, the porosity of composite vegetation concrete can also affect its own mechanical properties. Therefore, multiple factors need to be considered to determine the appropriate porosity. Plants usually live under moderate pH values, but due to the presence of cement, composite vegetation concrete exhibits strong alkalinity in the initial pores, which is not conducive to plant survival. Therefore, changing the alkaline environment in its pores is necessary. Measures such as controlling the amount of cement, adding mineral admixtures and adding a certain amount of acidifiers are usually taken to improve the alkaline environment in the concrete pores.The porosity and pH of the spray layer in the ecological protection of side slopes under composite vegetation concrete can affect the growth rate of vegetation. Therefore, this article analyzed the porosity and pH of the spray layer under composite vegetation concrete. In this paper, random sampling was adopted to sample the side slope protection under the composite vegetation concrete. The side slope area was 5000 square meters and one test point was selected for every 500 square meters. In this paper, random sampling method is used to conduct a sampling survey on the site of composite vegetation concrete slope protection. The slope area is 5000 square meters, and a test point is selected every 500 square meters. A total of 10 test samples were selected. The porosity and pH were divided into three grades. The porosity ≤ 25% was unqualified, while 25% < porosity < 45% was qualified and the porosity ≥ 45% was excellent. PH > 9 was considered unqualified, while 8 ≤ pH ≤ 9 was considered qualified and pH < 8 was considered excellent. The specific investigation results are shown in Fig. The x-axis in Fig. 19. Therefore, while ensuring a certain porosity, the number and area of connection points can be increased; the strength of the cement layer can be improved; the strength of the composite concrete can be improved. For stable slopes, the compressive strength of the composite concrete plant frame is about 10 MPa. The soil structure of stone side slopes mainly filled with soil has a high ecological protection effect.The bearing capacity of composite vegetation concrete is mainly transmitted by the bonding point between aggregates. Because the strength of aggregates is high and the bonding area between cement gel and coarse aggregate is small, its failure feature is the destruction of the bonding area of aggregate particles. The composite vegetation concrete side slope protection structure is a new type of side slope protection structure that can reduce the overall thickness of the required protective coverIn side slope protection, the effective water holding capacity of vegetation is a necessary condition to ensure the growth of plants, so the effective water holding capacity and compressive strength of the side slope under the composite vegetation concrete should be analyzed. Similarly, for the side slope of the composite vegetation concrete with an area of 5000 square meters, one test point should be selected every 500 square meters and a total of 10 test samples should be selected, of which the effective water holding capacity and compressive strength were divided into three grades. If the effective water holding capacity was less than 20%, it was unqualified. If the effective water holding capacity was less than or equal to 20%, it was qualified. If the effective water holding capacity was greater than or equal to 30%, it was excellent. Compressive strength < 0.25 MPa was considered unqualified; 0.25 ≤ compressive strength ≤ 0.35 was considered qualified; compressive strength > 0.35 was considered excellent. The specific investigation is shown in Fig. In Fig. In the ecological protection of stone side slopes, vegetation coverage and disease incidence are important criteria for judging their protection effectiveness. This article analyzed the vegetation coverage and disease incidence of a 5000 square meter rocky side slope by extracting one test sample every 500 square meters. The vegetation coverage rate and disease incidence rate were still divided into three levels. Vegetation coverage rate < 85% was considered unqualified; vegetation coverage rate < 95% was considered qualified; vegetation coverage rate > 95% was considered excellent. If the disease incidence rate was greater than 10%, it was considered unqualified; if the disease incidence rate was less than 5%, it was considered qualified; if the disease incidence rate was less than 5%, it was considered excellent. The specific investigation is shown in Fig. In Fig. 20. Based on the vegetation coverage rate, disease occurrence rate and effective water capacity investigated in the previous section, the ecological protection and side slope maintenance of side slopes were analyzed. The protective effects of ordinary concrete and composite vegetation concrete were compared and a total of ten side slopes were selected. The specific comparison results are shown in Fig. In the ecological protection of side slopes, vegetation coverage, disease occurrence rate and effective water capacity are the best indicators for evaluating ecological protectionIn Fig. Experimental research and field studies on plants (either cultivated or wild), including the collection of plant material, it comply with relevant institutional, national, and international guidelines and legislation. Where the grass seeds were obtained?-Purchased.Composite vegetation concrete technology organically combines engineering protection with vegetation protection, realizes the sustainable conservation of soil and water, and forms a modular function and an enhanced ecological landscape protection system. It can not only play the role of soil and water conservation, but also restore the ecological environment and strengthen the slope. When selecting composite vegetation concrete, it is necessary to reduce its pH value to achieve the environment needed for plant growth. Slope plants germinate quickly, with high germination rate and good greening effect. Under the protection of composite concrete, plants have good contact with soil and rock layers and can absorb nutrients from soil. In the future ecological protection, it is necessary to further study its raw materials, construction mixture ratio and construction technology. Standardize and standardize, and promote its popularization in ecological protection.


Understanding the relationship between inappropriate prescribing and patient insurance type could inform the targeting of antibiotic stewardship initiatives. However, few national data on this topic exist.BMJ 2019). We assessed the association between safety-net status and inappropriate antibiotic prescribing using linear regression, controlling for patient characteristics, calendar quarter, and specialty. Models accounted for the complex design of the survey and employed designed-based variance estimators.We analyzed the National Ambulatory Medical Care Survey, a nationally representative survey of office-based physician visits. We included all years from 2016 to 2019 except 2017, a year during which the survey was not fielded. We identified visits resulting in an oral antibiotic prescription among children and non-elderly adults who were privately insured, publicly insured, or uninsured. The exposure was safety-net status (publicly insured/uninsured versus privately insured). The outcome was inappropriate antibiotic prescribing, defined as an antibiotic prescription in a visit for which none of the diagnosis codes justified antibiotic use . Of 1,240,610,825 weighted visits for non-elderly adults, 11.0% resulted in an antibiotic prescription. Among these visits, the unadjusted prevalence of inappropriate antibiotic prescriptions was 50.1% overall, 60.7% for safety-net patients, and 47.9% for privately insured patients .Safety-net status was associated with a lower rate of inappropriate antibiotic prescribing among children but a higher rate among non-elderly adults. Antibiotic stewardship initiatives targeting clinicians who care for privately insured children and adults with safety-net insurance may be warranted.Jeffrey A. Linder, MD, MPH, FACP, Amgen, Biogen, Eli Lily: Stocks/Bonds