Recently, Riedel’s thyroiditis (RT) was assimilated into the larger spectrum of immunoglobulin IgG4-related disease (IgG4-RD) in addition to a particular frame of IgG4-related thyroid disease (IgG4-RTD), underlying IgG4-RT, IgG4-associated Hashimoto’s thyroiditis (and its fibrotic variant), and IgG4-related Graves’s disease. Our objective was to overview recent data on RT, particularly IgG4-RD and IgG4-RTD. The case and study– sample analysis (2019–2023) included 293 articles and selected 18 original studies: nine single case reports  and four case series . IgG4-RD and thyroid findings were analyzed in three cohorts (N = 25). Another two studies (N = 11) specifically addressed IgG4-RTD components. On presentation, the patients may have hypothyroidism, transitory thyrotoxicosis, goiter, long-term history of positive anti-thyroid antibodies, and hypoechoic ultrasound thyroid pattern. The 5-year analysis (N = 66) showed the rate of serum IgG4 evaluation remained low; normal values do not exclude RT. Mandatory histological and immunohistochemistry reports point out a high content of IgG4-carrying plasma cells and IgG4/IgG ratio. Unless clinically evident, histological confirmation provides a prompt indication of starting corticoid therapy since this is the first-line option. Surgery, if feasible, is selective . Current open issues are identifying the role of serum IgG4 assays in patients with IgG4-RD, finding out if all cases of RT are IgG4-mediated, applying IgG4-RTD criteria of differentiation among four entities, and providing an RT/IgG4-RTD guideline from diagnosis to therapy. It remains that the central aim of approaching RT in daily practice is the early index of suspicion in order to select patients referred for further procedures that provide enough histological/immunohistochemistry material to confirm RT and its high IgG4 burden. Riedel’s thyroiditis (RT), being strongly connected with positive antibodies against the thyroid, has been traditionally regarded as a particular type of autoimmune thyroiditis. However, during the last decade, RT was assimilated into the larger spectrum of immunoglobulin IgG4-related disease (IgG4-RD) and, recently in 2021), a proposal was released to designate a particular framework, namely, IgG4-related thyroid disease (IgG4-RTD) with four underlying entities: IgG4-mediated RT, IgG4-associated Hashimoto’s thyroiditis (and its fibrotic variant), and IgG4-related Graves’s disease , a propo Figure .The classical concept of RT involves a chronic inflammatory condition with a predominantly fibrotic pattern of infiltration located at the thyroid and surrounding areas . The level of statistical evidence is low (mostly of case reports and series); an estimated incidence of 1 to 1.06 cases per 100,000 people has been estimated, with women being more often affected , particularly those aged between 30 and 50 years ,4,5.Riedel’s thyroiditis results in a thyroid gland that is mostly firm  and enlarged causing local pain, compressive symptoms , and hypothyroidism (up to 80% of cases) in association with extra-thyroid fibrosis; unusual complications such as exophthalmos, Horner’s syndrome, or venous sinus thrombosis have been found as well ,4,6.Positive serum antibodies such as anti-thyroid peroxidase and anti-thyroglobulin are identified in 9 out of 10 patients. Blood inflammatory markers such as elevated C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) may be present in typical presentations associated with full-blown clinical manifestations ,4,7.Ultrasound and computed tomography might help the imaging diagnosis, particularly to prove the hypoechoic ultrasound pattern in association with avascular gland enlargement at Doppler examination and to show thyroid and extra-thyroid fibrosis extension at computed tomography or magnetic resonance imaging. Furthermore, ultrasound and computed tomography are also used to differentiate RT from malignancy  and to reveal non-thyroid spreading of IgG4-RD. Ultrasound elastography might highlight an elevated stiffness. 18-Fluoro-deoxyglucose positronic emission tomography/computed tomography may point out an increased tracer uptake at first presentation, while technetium (Tc) thyroid uptake is reduced at 99mTc thyroid scintigraphy ,8,9.RT confirmation comes from histological reports  based on lymphocyte infiltration, fibrosis, and destruction of thyroid follicles (which explains the long-standing primary hypothyroidism). No malignant or giant cell should be identified. A high amount of IgG4-carrying plasma cells represents the novel clue of RT. Of course, in order to provide the histological and immunohistochemistry features, an open/core needle biopsy is necessary ; thus, an index of suspicion should be kept in mind even in the early stages of the disease when classical clinical signs are not yet very suggestive ,6,10.Misdiagnosis as Hashimoto’s thyroiditis (mostly due to positive serum antibodies against the thyroid) or as a thyroid malignancy, particularly of anaplastic carcinoma, sarcoma, or primary thyroid lymphoma, is often described considering the anatomical aspects and progressive (severe) clinical evolution ,11. Delaβ), a cytokine released by fibroblasts and epithelial cells acting as a growth inhibitor of various cells (including fibroblasts) [Prompt intervention might improve the outcome. There is no consensus therapy in RT, which is rather a matter of individual decision, but glucocorticoid treatment  represents the first choice of medication. Currently, rituximab, a monoclonal antibody against CD20 protein, may be regarded as a second-line therapy. Tamoxifen (10–20 mg twice per day) has a longer history of use than rituximab as an additional drug to corticoids; it may be added to them or even offered as a single medication. This selective estrogen receptor modulator is beneficial not through its anti-estrogen capacity but via anti-fibrotic effects by stimulating transforming growth factor (TGF-oblasts) ,13. The oblasts) ,14.Low-dose radiation therapy at the thyroid level represents a rarely applied alternative . SurgeryThe natural history of RT is progression but spontaneous regression or episodes of relapse are reported in addition to medically-induced remission, which is mostly due to glucocorticoids. Disease-related mortality is rather low, but a severe impairment of quality of life is reported due to multiple complications and long-term medication ,6.Novel practical approaches to RT connect the disease with the larger area of IgG4-RD in terms of serum IgG4 assays but, mostly, the intra-thyroid IgG4 findings reflect their essential role in RT. The importance of serum IgG4 assays has been suggested for daily practice purposes and further guidelines are required. Controversies related to their low predictive value and correlations with active or inactive stages of the condition are still ongoing. Immunohistochemistry-based IgG4 stain is mandatory for RT confirmation by pointing out a high amount of IgG4-carrying plasma cells, and an increased IgG4/IgG ratio .IgG4-RD, a rare immunologic condition, presents as single or multi-organ/tissue spreading at pulmonary, orbital areas, salivary glands , biliary ducts and in the gallbladder (sclerosing cholangitis and cholecystitis), renal system , pancreatic system , and lymph nodes in association with various cardiovascular manifestations  ,24,25,26An IgG4-associated entity was first reported more than two decades ago (in 2001) in terms of pancreatitis  ,31; howeAt the onset, the lesions might mimic a malignancy (or a paraneoplastic syndrome) or an infectious disease or they may be mistaken as another autoimmune condition, while severe cardiac and vessel involvement should be differentiated from an acute myocardial infarction or rupture of an aortic aneurysm ,29,35. FCFHR1 and CFHR4 gene deletions has been suggested [The pathogenic traits of RT are yet poorly understood and are mostly related to polyclonal activation of plasma cells . The seruggested ,38. The uggested ,24. Needuggested .In terms of treatment, firstly, patients are candidates for glucocorticoid therapy, which might rapidly improve the clinical evolution in the majority of cases; thus, prompt and adequate disease recognition and intervention is important (if feasible) . Non-resOur objective is to review recent data on RT, particularly concerning IgG4-RD and IgG4-RTD.This is a narrative review. The case and study sample analysis included articles according to the following inclusion and exclusion criteria as displayed in We identified 293 articles  and selected 18 original papers for the final analysis  .Since 2019, nine case reports of a single patient per paper have been published according to our methods ,49,50,51On admission, a patient  may have a long history of multinodular goiter, Hashimoto’s thyroiditis , or hypoechoic pattern at ultrasound with or without associated hypothyroidism and not being categorized as RT during this time period unless a sudden/progressive thyroid enlargement with compression effects emerges ,44. GökçHypoparathyroidism due to RT-associated extensive fibrosis is found at first presentation, as well as a surgically-induced form in cases that require a large dissection or display adherent lesions at cervical areas . For insThe modern approach to RT, if suspected, takes into consideration the IgG4 profile. Serum IgG4 might not be increased in local (thyroid) forms of RT (with no other spreading of IgG4-RD) while immunohistochemistry provides a meticulous insight into IgG4-positive staining, which provides a clue regarding the specific case (regardless of the concentration of the serum IgG4 profile) . Five ouGlucocorticoid therapy improves the clinical presentation; if the onset is severe due to local compressive symptoms, prompt intravenous intervention is required  . In lessGökçay Canpolat et al.  added taMammen et al.  revealedA thyroidectomy, even if unsuccessful when performing a complete gland resection, serves two essential purposes: one is placing a transitory lifesaving tracheostomy if needed due to tracheal fibrosis and inflammation and the other is providing histological material to point out the IgG4-associated tissue burden . DespiteGenerally, in endocrine practice, fine needle aspiration is the first choice in different lesions at the thyroid after initial clinical and ultrasound detection regardless of the underlying pathological report ,59. Yet,Histological analysis after biopsy and/or thyroidectomy in association with IgG4 immunostaining was applied in three out of the four case series we could identify (case series of more than one patient with RT per paper) ,57,60 T.Generally, IgG4-RD criteria established by the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) in 2019 took into consideration RT as part of “head and neck gland involvement”. Hashimoto’s thyroiditis may be incidental (distinct from IgG4-RD), but it is part of the RT-associated picture if RT represents the single organ manifestation. As seen in other sites, the positive diagnostic of IgG4-RD is established by scoring clinical and radiological organ-specific findings or highly suggestive parameters provided by the pathological report. Moreover, serum IgG4 assays might prove normal in RT; however, a level of more than 2–5 times above the normal limit  represents one criterion associated with different scores depending on serum levels. Exclusion criteria are required, too, for providing a positive diagnosis of IgG4-RD ,33. In 2According to our sample-based analysis, we identified one study published in 2021 by Yu et al.  that wasSome studies enrolled patients with non-thyroid manifestations of IgG4-RD, but further on, the authors identified that subgroups of these subjects were associated with IgG4-mediated thyroid features consistent with IgG4-RTD. We identified three such studies ,62,63 T.One series of five subjects (mean age of 40.2 years) with IgG4-related vessel involvement at the aortic level and other arteries revealed a subject with RT (a diagnosis confirmed through thyroid biopsy). This was a 49-year-old female who presented complications at the carotid, subclavian, and pulmonary arteries, and a small increase in serum IgG4 without hypothyroidism. The general IgG4-related condition responded well to glucocorticoid therapy . We alsoCurrently, despite being an unusually rare entity, RT has been added to the larger register of IgG4-RD, thus many practitioners other than endocrinologists and surgeons might have to take into consideration thyroid involvement due to IgG4 connections ,61,62,63Another point is represented by the importance of the immediate use of glucocorticoids which remain the first-line approach. Other drugs such as tamoxifen and rituximab might prove useful in selected cases. Surgery, although not a first-line option unless an emergency, still represents a strong player in overall management from open biopsy to tracheal intervention ,61,62,63p = 0.001). Among endocrine conditions within the first subgroup, we mention Hashimoto’s thyroiditis in seven subjects (7.5%) and Graves’s disease in eight individuals (representing 8.6%) [A third chapter  is the potential role of other contributors to RT (other than IgG4). For instance, smoking might negatively influence an autoimmune disease as reported by Pandev et al. , but we ng 8.6%) .RT was first identified by the surgeon Bernhard Moritz Carl Ludwig Riedel in 1883 who later reported it in 1894 at a surgery conference and published it in 1896 . FurtherIn 2021, Takeshima et al. [In 2021, Yu et al.  reviewedTo the best of our knowledge, the highest number of RT-published cases so far is 212 (an article from 2020) [IgG4-carrying cells (in addition to an increased IgG4/IgG ratio) are mandatory to be highlighted based on immunohistochemistry analyses. It is imperative to obtain enough tissue following thyroidectomy or open/core/surgical biopsy in order to analyze the IgG4 status. In addition to this assessment, meticulous histological description, clinical presentation (thyroid enlargement and woody consistency), and other fibrotic or sclerotic potential involvement at non-thyroid organs help the distinction among the four types of IgG4-RTD ,73. SomeDue to the rarity of IgG4-RTD, a limited number of clinical studies are reported so far, addressing distinct entities among the condition ,77 Tabl.One study from Korea (between 2017 and 2021) included five patients with IgG4-RTD (two cases with IgG4-RT and three subjects with IgG4-mediated Hashimoto’s thyroiditis). The individuals with RT had an immunohistochemistry-based confirmation in terms of high content of IgG4-positive plasma cells and elevated IgG4/IgG ratio  . NotablyA subgroup of the patients confirmed with Graves’s disease (even complicated with eye involvement) might present an IgG4-related ophthalmic disease or they may associate other (non-thyroid) multi-organ manifestations of IgG4-RD ,79. A diAs mentioned, a small number of patients confirmed with Hashimoto’s thyroiditis develop its fibrotic variant, with this entity belonging to IgG4-RTD . Most aup = 0.0001), with the value of >180 mg/dL being associated with a 75% sensitivity and a 100% specificity. Serum antibodies against thyroid correlated with the levels of blood IgG4 (p = 0.001). This interesting approach requires further study. Currently, we do not place the serum assessment of IgG4 in daily endocrine practice as a prediction marker in suspected nodules for malignancy [Collaterally, we mention a different approach to serum IgG4 assays and thyroid lesions in a study conducted by Elshaer et al. . The autlignancy .IgG4, a subclass of IgG, plays an important role in human immune response, particularly immune tolerance. The conditions involving this particular type of IgG4 are IgG4-autoimmune diseases or IgG4-RD characterized by fibrosis, sclerosis, and phlebitis . We specWe cited Pacella et al.  reportinRemarkably, a previously published study by Watanabe et al.  highlighIgG4-mediated endocrine diseases are IgG4-related thyroiditis of four types, as mentioned above, and IgG4-associated hypophysitis  ,103,104.Overall, we identified nine single case reports , four case series of patients with RT , three studies in patients with IgG4-RD identified 25 patients with RT , and two original studies specifically addressed IgG4-RTD components .A total of 66 subjects with RT are included in our analysis based on published cases. The rate of serum IgG4 evaluation remained low; normal values do not exclude RT ,61,62,63It is possible that the frequent co-presence of autoimmune anti-thyroid antibodies in RT led us to focus our attention in the wrong direction (toward a particular type of autoimmune thyroiditis). RT should be assimilated to the larger picture of IgG4-RDs (or IgG4-associated sclerosing disease), which currently seems to display a chapter of its own in many medical and surgical domains other than thyroid. IgG4 immunostaining should become the new norm in RT. Applying the proposed criteria of IgG4-RTD might differentiate RT from other non-RT entities and raise the issue of potential non-thyroid IgG4-involvement in RT. This novel direction of classification and approach with respect to RT should emerge into an “omic” perspective of the condition, not just of a thyroid disorder, as part of IgG4-RD, with RT representing either a type of IgG4-RD with isolated organ involvement or being associated with synchronous/asynchronous multiple site spreading of IgG4-RD ,32,33.The new concept of IgG4-related RT is yet to be explored while gathering multi-level, multi-disciplinary data is mandatory. Routinely checking the thyroid status  in subjects confirmed with any type of IgG4-RD should be conducted, but the timing of serial check-ups is still an open issue. Suspecting RT should be associated with serum IgG4 testing  and a histological report and IgG4 stain since prompt glucocorticoid therapy might release local symptoms and avoid unnecessary complications in many cases. Further data on the IgG4-RT relationship are needed, as are interventional studies and longitudinal RT data.The spectrum of IgG4-RTD varies from mild thyroid dysfunction (mostly hypothyroidism) in patients with high serum IgG4 and other non-thyroid manifestations  or with classical features of woody thyroiditis (RT) displaying a very aggressive profile and a poor outcome due to local evolution. The most recent 5-year RT analysis showed reports with a traditional RT (severe) presentation or cases with a fine index of suspicion concerning IgG4 contribution rather than through the clinical picture. The level of statistical evidence remains low in either scenario. Finally, from new pathogenic traits involving IgG4 to challenging endocrine and surgical aspects, RT remains one of the most interesting and fascinating topics in the thyroid domain.


The entry of aggressive substances into the pore structure of concrete causes the development of corrosion processes and leads to the destruction of the cement stone structure. Hydrophobic additives provide high density and low permeability and are an effective barrier to the penetration of aggressive substances into the structure of cement stone. To assess the contribution of hydrophobization to the durability of the structure, it is necessary to know how much the processes of corrosive mass transfer slow down. To study the properties, structure and composition of the materials studied in the work (solid and liquid phases) before and after exposure to liquid-aggressive media, experimental studies were carried out using chemical and physicochemical analysis methods: determination of density, water absorption, porosity, water absorption and strength of cement stone; differential thermal analysis; quantitative analysis of calcium cations in liquid medium by complexometric titration. The article presents the results of studies of the effect on the operational characteristics of the introduction of a hydrophobic additive of calcium stearate into the cement mixture at the stage of concrete production. The effectiveness of volumetric hydrophobization was evaluated to prevent the penetration of an aggressive chloride-containing medium into the pore structure of concrete destruction and the leaching of calcium-containing components of cement stone. It was found that the introduction of calcium stearate in an amount of 0.8–1.3% by weight of cement increases the service life of a concrete product during corrosion in liquid chloride-containing media with a high degree of aggressiveness by four times. During the operation of concrete, various aggressive substances affect it, which leads to a decrease in its durability. The durability assessment is related to the expected performance characteristics of the product and consists in determining the factors that are crucial for the destruction of the material depending on its composition and properties, determining changes caused by the interaction of the material with external-aggressive media, and measuring damage over time.The main physicochemical processes of destruction in reinforced concrete products occur due to the penetration of water into the concrete structure ,2,3,4,5.In order to prevent and reduce the penetration of water and dissolved aggressive substances into the pore structure of concrete, its hydrophobization is ensured. The purpose of volumetric hydrophobization is to compact concrete to prevent water ingress and/or to make the capillary surface non-wettable, which will eventually reduce water penetration.Special additives are used to create waterproof concrete. They reduce the probability of water ingress, reducing the permeability and shrinkage of concrete during drying . Additiv2 is used for recrystallization and formation of new, more stable C-S-H and C-A-S-H phases in the presence of water , CP is equivalent capillary pressure resulting from water saturation of materials [MPa], and n is the indicator of the degree of the kinetics of water saturation of the material, determined by the formula:1 and Δ5 are arithmetic mean values of the mass difference of water-saturated and dried samples for 1 and 5 min, respectively; λ is the criterion determined by the formula:CiV is the volume of capillary pores of the material in the test sample, [cm3]; ΔCV1 is the volume of water absorbed by the capillaries of the material in 1 min, [cm3]; τ′ is relative reduced time, depending on the size and shape of the tested samples (from MI 2625-2000).The grade of concrete for water resistance was determined according to the method described in the patent  and MI 2VC1 is calculated by the formula:W is the volume of the mixing water in 1 L of the compacted mixture of the material, [cm3]; S, L are the content by weight of fillers in 1 L of a compacted mixture of material, respectively small and large, [g]; β1, β2 are water absorption of aggregates in fractions of their mass during mixing and compaction of the mixture, respectively, small and large, [cm3/g]; K3, K6 are coefficients from MI 2625-2000; ΔV′ is the specific current contraction of the cement used at the time of testing the material (ΔV′ = 2486 cm3/g); C is the content by weight of cement in 1 L of compacted mixture, [g].The value of ΔCP is calculated by the formula:A1 is constant from in MI 2625-2000; f is the coefficient reflecting the ratio of the volume of concrete to the volume of its mortar part; M1 is the parameter that integrally reflects the features of the capillary structure and the «overflow» effect is calculated by the formulas:–M = 6 + 300for concrete with a large aggregate: –M = 12 + 540for fine-grained concrete: The equivalent capillary pressure V is the volume of the test sample, [cm3].The volume of capillary pores in the material of the tested concrete sample is determined by the formula:f is determined by the formula:The coefficient Lγ is the true density of coarse aggregate, [g/cm3]; K5 is the stoichiometric constant from MI 2625-2000.The capillary porosity of the solution part is determined by the formula:iP value W given in GOST 12730.5-2018 «Concretes. Methods for determination of water tightness»  and V is sample volume, [cm3].The density of concrete The true density of concrete is determined by measuring the mass of the unit volume of the crushed and dried sample. The initial sample is crushed in a laboratory crusher to a size of less than 5 mm, mixed, and reduced to 150 g. The resulting sample is again crushed to a size of less than 1.25 mm, mixed, and reduced to 30 g. Then it is crushed in a mortar to a powdery state (less than 0.125 mm), dried to a constant mass, cooled to room temperature, and two samples of 10 g each are weighed.Each sample is poured into a clean, dry pycnometer, where distilled water at room temperature is poured in such an amount that the pycnometer is filled with no more than half of its volume. The pycnometer is placed in a slightly inclined position on a sand or water bath; its contents are boiled for 20 min to remove air bubbles. After removing the air, the pycnometer is wiped, cooled to room temperature, filled to the mark with distilled water, and weighed. Then the pycnometer is released from the contents, washed, filled to the mark with distilled water at room temperature, and weighed. ρ is calculated by the formula:m is the mass of the crushed sample, [kg], wρ is water density, [kg/m3], m1 is the weight of a pycnometer with distilled water, [kg], and m2 is the mass of the pycnometer with a sample and distilled water, [kg].The true density of concrete Water absorption is determined by testing a series of samples with dimensions 10 × 10 × 10 cm. The samples are placed in a container filled with water at a temperature of 20 ± 2 °C above the upper level of the stacked samples by about 50 mm. Samples are weighed every 24 h on a scale with an error of no more than 0.1%. When weighing, the samples are pre-wiped with a wrung-out damp cloth. The mass of water flowing out of the pores of the sample on the scale cup is included in the mass of the saturated sample. The test is carried out until the results of two consecutive weight measurements differ by no more than 0.1%.mW by weight as a percentage with an error of up to 0.1% is calculated by the formula:cm is the mass of the dried sample, [g], and wm is the mass of the water-saturated sample, [g].The water absorption of concrete of a separate sample W0 by volume as a percentage with an error of up to 0.1% is calculated by the formula:ρ0 is the average density of dry concrete, [g/cm3] and wρ is the density of water assumed to be equal to 1, [g/cm3].The water absorption of concrete of a separate sample pV concrete is calculated as a percentage with an error of up to 0.1% according to the formula:ρ is the true density of concrete, [kg/m3] and dρ is the density of dried concrete, [kg/m3].The total pore volume of oV is assumed to be equal to the water absorption of concrete by volume W0.The volume of open capillary pores of concrete (sample) cV is calculated by the formula:The volume of conditionally closed capillary pores of concrete The strength was determined using a hydraulic press P-50 on samples of cement stone with a face length of 10 cm. The working area of the press consists of two horizontal plates mounted on a column with a lead screw. During the compression test, the samples were installed on the lower base plate of the press centrally relative to its longitudinal axis.After installing the test sample on the base plates of the press , the upper plate was combined with the upper support face of the sample  so that their planes were completely adjacent to each other. Then the loading began.The loading of the samples was carried out continuously with a constant rate of increase of the load until their destruction. At the same time, the loading time of the test sample before its destruction was at least 30 s. The maximum force achieved during the test was taken as a destructive load.cR for each sample is calculated by the formula:α is the scale factor for reducing the strength of concrete to the strength of concrete in samples of basic size and shape, assumed to be 0.95 according to GOST 10180-2012 «Concretes. Methods for strength determination using reference specimens» ; A is the area of the working section of the sample, [mm2].The compressive strength of concrete ecimens» ; F is deDifferential thermal analysis (DTA) is a method of studying physical and chemical transformations accompanied by the release or absorption of heat. The method is used to register phase transformations in a sample and study their parameters. The analysis was carried out according to the standard method on the Q-1500D derivatograph.In preparation for the study, the cement stone is crushed to pieces of 1-3 mm in size. The weight of crushed cement stone weighing 1–2 g is transferred to the box, filled with 100% ethyl alcohol, and left for 10 h. To separate the material from alcohol, filtration is carried out through a paper filter. The dehydrated material is crushed in a mortar to powder. Then, 0.5–1 g is taken from the powdered material, which is placed in the crucible of the derivatograph.At a heating rate of 10 °C/min and a temperature range of 20–1000 °C, the temperature curve and the mass loss curve of the substance are fixed. The analysis of the derivatograms was carried out according to the standard methodology.The complexometric determination of calcium cations is based on direct titration of the test solution with a standard solution of complexon III with the addition of indicators of murexide or dark blue chromogen. The indicators form a complex compound of red color with calcium ions. When titrating the test solution with complexon III at the equivalence point, the red color changes to the color characteristic of the free indicator.A total of 25 mL of the analyzed solution is pipetted into a conical flask, and 50 mL of distilled water, 25 mL of a 20% sodium hydroxide solution, and 2–3 drops of the indicator are added to it. Then the test solution is titrated with a 0.1 N solution of complexon III with continuous stirring until the red color changes to purple or blue. In the end, titration is carried out very slowly.Ag is the total content of calcium cations in solution, [g]; AE is the equivalent of calcium cations; BN is the concentration of standard EDTA solution, [eq/L]; BV is the volume of standard EDTA solution spent on titration, [mL].The calculation of the content of calcium cations in the solution is carried out according to the formula:C is the concentration of «free calcium hydroxide» in concrete at time τ [s] at an arbitrary point with the x coordinate [m], in terms of CaO, [kg CaO/kg concrete]; k is the mass conductivity coefficient, [m2/s]; vq(x) is the source of the mass of the substance as a result of a chemical reaction, [kg/(m3·s)]; conρ is concrete density, [kg/m3]; δ is the wall thickness of the structure, [m]; C0(x) is the concentration of «free calcium hydroxide» in concrete at the initial moment of time at an arbitrary point with the x coordinate, [kg CaO/kg concrete]; nq is the density of the mass flow of a substance from concrete into a liquid medium, [kg/(m2·s)].When studying the II type of corrosion of cement concretes by our scientific school for the system under consideration, «cement stone–aggressive component», the mass transfer equations for calcium hydroxide are presented in the form of the following boundary value task :(17)∂Cx,The initial condition (Equation (18)) shows that at the time taken as the starting point, the concentration of the transferred component  has a distribution over the thickness of the concrete structure.The boundary condition (Equation (19)) is a condition of non-penetration at the outer boundary of the structure.The boundary condition (Equation (20)) is a condition of the second kind and shows that there is a mass transfer between the solid and liquid phases at the boundary of the structure with a liquid medium.n is the number of row members; ξ is the coordinate of integration in the range In the final form, the boundary value problem of mass conductivity in dimensionless variables is written:Images of the cement stone surface  were obtDuring the setting period of the cement dough (from 0 to 2 h), moisture evaporation occurs faster in cement samples without additives than in hydrophobized ones . The begThe results of the studies show that in samples with a concentration of calcium stearate of 1.1%, the mass change at the initial stage of hardening occurs uniformly. During the first 12 h, in samples with a hydrophobic additive content of 0.8% and 1.3%, the mass change occurs most intensively, while the concentration of the additive in the amount of 1.1% does not significantly affect the change in the mass of the samples compared to the sample without additives.A greater change in the mass of samples with the addition of 0.8% and 1.3% calcium stearate may be due to the fact that the particles of the hydrophobizer slow down the interaction of the cement mixture with water, as a result of which the water remains on the surface and does not settle but evaporates. The difference in the intensity of the change in the mass of cement stone samples with hydrophobic additives during hardening may be due to the different distribution of calcium stearate particles in the cement volume during mixing.However, after a day, the trend of changing the mass of samples does not persist, as can be seen in It is known that hydrophobic additives introduced into concrete at the manufacturing stage contribute to improving its operational characteristics ,54,55,60An increase in density due to a decrease in porosity should help slow down the penetration of an aggressive medium deep into the cement stone of concrete and inhibit the development of corrosion processes.2 solution. The content of calcium cations in the liquid medium was determined by the method described in Determination of the kinetics of dissolution and leaching of calcium ions from cement stone by an aggressive chloride-containing medium was carried out when samples were immersed in a 2% MgClIt is obvious that for cement concrete containing 1.1 and 1.3% by weight of the hydrophobizer, the kinetics of calcium leaching in an aggressive environment is almost the same ) ) .2 solution were calculated ]; ρ0 is the density of the solid phase, [kg/m3].liqC is the mass of the substance transferred from the cement stone to the liquid medium, [kg]; S is the area of the corroded concrete surface, [m2]; τ is the process time, [s].According to formulas (Equations (22) and (23)), the characteristics of the mass transfer process of “free calcium hydroxide” during the corrosion of hydrophobic concrete in 2% MgCllculated .(22)k=qβ. It is defined as the ratio of the diffusion flux q to the concentration difference ∆C, [kg/m3]:To calculate the processes of substance transfer, it is convenient to enter the mass transfer coefficient 2 solution varies exponentially. The curves have a flatter appearance compared to the curve of a non-hydrophobized sample, which indicates a significantly lower rate of corrosion processes in this case. The mass transfer coefficients behave in a similar way , which can be used to establish the terms of safe operation of concrete structures.The paper defines the main parameters of corrosion mass transfer (coefficients of mass conductivity and mass transfer) for Portland cement of the CEM I 42.5 N brand with the addition of a calcium stearate hydrophobizer in a highly aggressive medium, which can be used to calculate the service life of concrete and reinforced concrete products using mathematical models of corrosion.The obtained ideas about the corrosion destruction of hydrophobized concrete, taking into account the regularities of mass transfer processes, allow us to predict the effects of liquid media of varying degrees of aggressiveness on concrete and develop recommendations for improving the corrosion resistance of concrete and reinforced concrete products.


Surveillance of hospital antibiotic consumption provides data to inform corrective action and for monitoring antimicrobial stewardship activities. This study described antibiotic consumption patterns from 2016 through 2021 at a secondary healthcare facility in Ghana.Using the WHO methodology for surveillance of antimicrobial consumption in hospitals, we analysed a 6-year pharmacy issue data at the Eastern Regional Hospital. We report on the defined daily dose (DDD) per 100 patients, types of antibiotics consumed according to Anatomic Therapeutic Classification (ATC), WHO AWaRe classification; trends in antibiotic consumption and expenditure per DDD of antibiotics consumed.P = 0.247). The top three consumed antibiotics in DDD/100 patients at ATC level 5 were amoxicillin-clavulanate (n = 372.6), cefuroxime (n = 287.4) and sulfamethoxazole-trimethoprim (n = 145.8). The yearly Access-to-Watch ratio decreased from 2.4 in 2016 to 1.2 in 2021. The mean yearly cost of antibiotics was $394 206 ± 57 618 US dollars. The top three antibiotics consumed in terms of cost were clindamycin $718 366.3, amoxicillin-clavulanate $650 928.3 and ceftriaxone $283 648.5.Over the period, the mean (±standard deviation) antibiotic consumption rate was 256.7 ± 33 DDD/100 patients per year. A linear regression model showed an insignificant decreasing trend in antibiotic consumption (coefficient for time –0.561; This study showed a sturdy rate of antibiotic consumption over the 6-year period with a year-on-year decrease in the Access-to-Watch antibiotic ratio. Data from pharmacy drug issues offer an opportunity to conduct antibiotic consumption surveillance at the hospital and national level in Ghana. AMR is considered a global public health problem.3Globally, there has been a 65% increase in antimicrobial consumption (AMC) in humans between the years 2000 and 2015, with this increase driven mainly by low- and middle-income countries.4–7 The Ghana national policy and action plan on AMR that is aligned with the global action plan on AMR highlight the need to strengthen surveillance and research as well as optimize the use of antimicrobials.8 Optimizing antimicrobial use and consumption through antimicrobial stewardship hinges on the availability of antimicrobial use and consumption data. Antimicrobial use and consumption data can provide warning signs concerning antimicrobial exposure and use, allowing for the institution of corrective measures. It may also serve as a monitoring tool for interventions aimed at reducing antimicrobial exposure.9 In Ghana, surveillance of antimicrobial consumption at the hospital and national level is lacking, however, several point prevalence surveys on antimicrobial use have shown 47% to 66% prevalence of antimicrobial use among hospitalized patients.10–13 Currently, Ghana is undergoing a national digitalization agenda that includes the provision and use of electronic health records in healthcare facilities. Electronic health records of hospital pharmacies and doctors’ prescribing notes represent low-hanging fruit for conducting surveillance of antimicrobial use and consumption at the hospital level in Ghana.Several reports from Ghana show increasing AMR, with a high prevalence of resistance phenotypes such as extended-spectrum beta-lactamases and increasing reports of carbapenemase-producing bacteria.14 is a secondary referral facility that provides a range of specialist services for the >2 million people living in rural and urban settings in the Eastern region of Ghana.15 The hospital has a history of electronic health records use for the past 6 years and has accumulated records useful for conducting antimicrobial consumption studies. These data could provide an understanding of one of the potential drivers of AMR in the hospital and inform antimicrobial stewardship strategies. In this study, we evaluated the antibiotic consumption trends at the ERH from 2016 through 2021 using WHO’s defined daily dose (DDD) methodology.The Eastern Regional Hospital (ERH),17 we analysed a 6-year pharmacy central pharmacy issues data. The central pharmacy stores of the hospital dispense drugs to pharmacy units associated with various departments of the hospital. The Pharmacy Department distributes drugs using the stock system, where dispensed drugs through the supply chain are recorded. Patients pay for any drugs consumed with cash or through the National Health Insurance System. A recent point prevalence survey conducted at the hospital showed an antimicrobial use prevalence of 50%.13 The hospital uses the national standard treatment guidelines as the main document supporting antimicrobial prescriptions although other documents such as the British National Formulary are used.18 The ERH has a microbiology laboratory that routinely performs bacterial cultures and antimicrobial susceptibility testing. The hospital’s Information Technology Department manages electronic health records where medical records of patients and pharmacy data are stored.Using the WHO methodology for the global programme on surveillance of antimicrobial consumption in hospitals,™-based data collection instrument. Data extracted included the antibiotic name, the dosage, route of administration, quantity, date dispensed and the cost of the issued antibiotics. No patient-level information on prescriptions—e.g. indication or age of the patient—was available. Total patient attendance to the hospital for the years under consideration was retrieved. In this study, we included only data on antibiotics for systemic use, classified in the J01 category, by the WHO Anatomic Therapeutic (ATC) classification system.17 The WHO also recommends categorizing antibiotics as Access, Watch or Reserve (AWaRe),20 and we used the 2021 database20 to classify them accordingly. Topical antibiotics were excluded from the study. Antimicrobials used for managing tuberculosis, parasites and fungi were not also included.Data summaries on antibiotics dispensed over 71 consecutive months from January 2016 through November 2021 were copied from pharmacy electronic records and transferred to an Excel16 Each antibiotic was assigned to a WHO ATC level 4 and 5 classifications. We then expressed the number of drugs dispensed for each antibiotic class as our consumption data in DDD according to WHO methodology.16 The DDD is the assumed average maintenance dose per day for a medicine used for its main indication in an adult. It is a globally accepted unit for measuring drug consumption of different strengths or combinations and can be used to compare rates between different antibiotic categories and years.20 The DDD was calculated by converting the total amount of antibiotic dispensed in into grams and divided by the standard WHO ATC DDD value given in grams. When measuring antibiotic consumption in a hospital, where attendance data is available but no patient-level information can be accessed, DDD per 100 patients is the recommended method for standardization.16 In this study, we used total patients’ attendance at ERH to represent the population served by the hospital. This was the closest and best representation of the population served by the hospital, as most in- and outpatients are accounted for in the patient attendance data. The DDD/100 patients were obtained by dividing the calculated total DDD for each year by the patient attendance for the respective year and multiplying the ratio by 100. The expenditure on antibiotic consumption was calculated as expenditure per DDD by multiplying the number of antibiotics issued in a period  and the cost and dividing by the calculated DDD of the antibiotic for that period. For subgroup analysis, we compared yearly variations in antibiotic consumption for drug categories (e.g. AWaRe) by calculating the per cent contribution of that antibiotic category to the overall antibiotic consumption that year.Antibiotic consumption was estimated on the basis of the amount dispensed from the central pharmacy store in standard units of milligrams or millilitres. Each standard unit was defined based on a single tablet, capsule, ampoule, vial or liquid preparation for oral consumption.® 2021 and exported to the STATA® software for descriptive and analytical studies. Continuous variables were presented as means ± standard deviations (SD) and sums. Categorical variables were presented as frequencies and percentages. Difference in antibiotic consumption across the years was determined using Chi-square test, with the Marascuilo’s post hoc procedure applied for subsequent pairwise comparisons. The Chi-square trend analysis was used to compare the trend in consumption of WHO AWaRe antibiotic groups over the years. Measures of relative consumption, expressed as a percentage of the total consumption of groups of antibiotics, were derived for each antibiotic. A linear regression model was used to assess the trend of antibiotic consumption rate over time. The coefficient for time and P value for the trend of antibiotic consumption was calculated using yearly measures. All statistical tests were considered significant at a P value <0.05. The cumulative change in consumption for each antibiotic over the study period was calculated by adding the absolute differences in DDD/100 patients between 2017 and 2016, 2018 and 2017, 2019 and 2018, 2020 and 2019, and 2021 and 2020. With regards to the cost of consumed antimicrobial agent in US dollars ($), the amount of antimicrobial agent in Ghana cedi was converted to dollars using the average yearly dollar rate.Data were entered and cleaned using Microsoft ExcelEthical clearance for the study was obtained from the Ghana Health Service Ethics Review Committee with protocol number GHS-ERC 004/05/22. All data extracted from the EHR were summaries and aggregated data from antimicrobials issued from the pharmacy stores between 2016 and 2021. No individual patient records were collected, thus findings from the study cannot be linked to any patient.n = 1455.46/84.5) of the total volume in DDD of antibiotics issued over the 6 years.Over the 6-year survey period, we extracted data summaries on 15 different antibiotics at ATC level 4  and 26 antibiotics at ATC level 5  from the electronic records at ERH for analysis (Table P = 0.247). Differences in annual antibiotic consumption levels were not significant for the 6 years under study . When follow-up pairwise comparisons were conducted with Marascuilo’s post hoc procedure, none of the annual variations in antibiotic consumption between any pair of years from 2016 to 2021 was significant . Of the total antibiotics consumed DDD/100 patients, 87.7% (n = 1354/1543.9) were oral agents. Figure n = 1526.4/1543.9) of the total consumed antibiotics were generic brands.Figure n = 564.79/975.11) of the antibiotics consumption in DDD/100 patients over the 6 years belonged to the Access group and there was no consumption of Reserve antibiotics over the period of study. Unclassified antibiotics represented 0.026 DDD/100 patients accounting for 0.002% of total consumed antibiotics. Figure χ2 trend, P = 0.0001) in the consumption rate of Watch antibiotics from 2016 to 2021 and a commensurate progressive decrease in consumption of Access class of antibiotics . For example, in 2016, 70.5% (n = 180.1/255.4) of the total DDD/100 patients belonged to Access group of antibiotics and this decreased to 54.9% (n = 135.0/246.1) in 2021. In contrast, the proportion of Watch antibiotics contributing to total DDD/100 patients was 29.5% (n = 73.4/255.4) in 2016 and increased significantly over the years to 45.1% (n = 111.1/246.1) in 2021. The Access-to-Watch ratio, based on antibiotic consumption rate in DDD/100 patients, versus the year graph is displayed in Figure n = 287.4), azithromycin (n = 88.4), ciprofloxacin (n = 82.9), ceftriaxone (n = 41.9) and clarithromycin (n = 39.9) (Table JAC Online). The top five Access antibiotics with the highest DDD/100 patients were amoxicillin-clavulanate (n = 372.6), sulfamethoxazole-trimethoprim (n = 145.8), metronidazole (n = 127.8), doxycycline (n = 95.8) and clindamycin (n = 91.9).Most , second-generation cephalosporins (n = 287.4), combinations of sulfonamides and trimethoprim including derivatives (n = 145.8), macrolides (n = 142.3) and imidazole derivatives (n = 127.9). The complete list of antibiotics at ATC level 4 and their yearly consumption rates at can be found in Table n = 372.6), cefuroxime (n = 287.4), sulfamethoxazole-trimethoprim (n = 145.8), metronidazole (n = 127.9), and doxycycline (n = 95.9) [Figure The DDD/100 patients according to ATC level 4 is presented in Figure ) Figure . SufficeFigure The total cost of antibiotics over the 6 years was $2 365 241 with a yearly mean cost of $394 206 ± 57 618. The least gross amount of $301 011.7 was spent on antibiotics in 2020 and the highest amount of $494 934 was spent in 2018. The yearly average cost of antibiotics per DDD was $0.89 (SD 0.06), ranging from $0.83 in 2020 to $0.95 in 2016. Patients attending the ERH spent a mean of $2.3 ± 0.3 on antibiotics per visit to the hospital. The top five antibiotics contributing to overall antibiotic cost over the 6-year period were clindamycin ($718 366.3), amoxicillin-clavulanate ($650 928.3), ceftriaxone ($283 648.5), cefuroxime ($262 708.9) and metronidazole ($80 258.5).1 Data on antibiotic consumption are critical in informing and evaluating antimicrobial stewardship programmes implemented at the hospital and national levels to combat AMR. This study found an insignificant drop in antibiotic consumption from 2019 to 2021 compared to 2016 to 2018, with the most consumed antimicrobial in the hospital being amoxicillin-clavulanate.Globally, antibiotic consumption has increased over the last two decades, fuelled mainly by consumption in LMICs.13 These antibiotics are recommended for the treatment of upper and lower respiratory tract and urinary tract infections by the Standard Treatment Guidelines of Ghana,18 and they are on the national health insurance of Ghana’s list of drugs,21 so are not prohibited by out-of-pocket cost. On the contrary, agents like ceftriaxone which feature prominently as part of the top five antibiotics used in most point prevalence surveys in Ghana was the tenth most consumed antibiotic in this study.13 Also, there was sharp rise in the consumption of azithromycin in 2021. This could be due to increased use as a result of speculations that suggested azithromycin as an agent for treating COVID-19. This highlights the important role of antibiotic consumption surveillance or studies in its ability to give a complete antibiotic utilization picture compared to point prevalence surveys. It is of interest to note, however, that other antibiotics such as clindamycin and ceftriaxone were responsible for the first and third antibiotics when expenditure was assessed.Antibiotic consumption in the hospital increased from 2016 to 2018 and decreased sharply between 2019 and 2020 before beginning to rise again in 2021. Whereas the drop in 2020 antibiotic consumption may be attributed to the COVID-19 pandemic and the consequent drop in hospital attendance, it is not easy to fathom the sharp drop in antibiotic consumption in 2019. One possible reason could be stockouts; however, this study did not have access to this data. Amoxicillin-clavulanate and cefuroxime were the two commonest antibiotics consumed in the hospital over the study period. Similarly, these agents have been documented as part of the top five antibiotics used in hospitalized patients from previous point prevalence surveys in Ghana.20 This rise in Watch antibiotic use relative to the Access group of antibiotics is similar to global findings especially those from lower- and middle-income countries (LMICs) and may be a reflection of increasing antibiotic resistance observed in the study setting as has been suggested elsewhere.22 Increasing the use of Watch antibiotics could also be attributed to improved economic status in many LMICs with an associated increased purchasing power for more expensive broad-spectrum antibiotics,1 and uncertainty concerning febrile illness diagnosis. 23 There was no consumption of reserve antibiotics in the hospital over the study period, this may be a result of their unavailability on the local market, absence in the Standard Treatment Guidelines of Ghana18 and the fact that they are not funded by the health insurance scheme 21. Similar absent use of reserve antibiotics has been documented in point prevalence surveys among hospitalized patients in Ghana.25Overall, most antibiotics prescribed belonged to the Access group of antibiotics, however, the proportion of Watch antibiotics consumed yearly increased from 2016 to 2021 and is exemplified by a decreasing Access-to-Watch index from 2.4 in 2016 to 1.2 in 2021. This means that as of 2021 antibiotic consumption in the hospital did not conform to the WHO target, which requires at least 60% of overall antibiotic consumption to be made of the Access group of antibiotics.This study has potential limitations. First, the study is limited to one secondary healthcare facility thus finding may not be generalizable to other healthcare settings. Second, the data could not be segregated into outpatient and inpatient status that would have been useful to show any differences in antibiotic consumption patterns. However, our data showed that 90% of antibiotics were oral formulations, which suggests that a large proportion of consumed antibiotics was prescribed to outpatients. Antibiotic consumption data for 2021 was short by 1 month due to a change in EHR at the hospital, and this may have affected the overall antibiotic consumption observed especially for that year. The level of antibiotic resistance in the population under study is unknown and this could have given better meaning to the observed antibiotic consumption. Also, the findings in this study are not commensurate with the appropriateness of use. This study used hospital antibiotics issue data that are dependent on the medications stocked by the hospital and did not account for medications that were prescribed and purchased in pharmacies outside the hospital for use in the hospital by individual patients. This could explain the lack of data on reserve antibiotics that were not stocked by the hospital. Also, the data collected did not account for stockouts that could have affected consumption levels. However, findings from this study are useful because it is one of the first to describe hospital-wide antibiotic consumption in Ghana and describes the potential use of drug issuance data as a measure of hospital-level antibiotic consumption. These data could serve as baseline data for future studies and antibiotic stewardship initiatives.20 Third, there is also the need to strengthen AMR surveillance activities at the hospital to monitor the impact of the increase in the use of Watch antibiotics.This study has the following policy implications. First, data from pharmacy drug issues may be a useful resource for conducting antibiotic consumption surveillance at the hospital and national level and may represent low-hanging fruit for consumption surveillance in Ghana considering the EHR rollout across healthcare facilities. Second, there is a need to understand the reasons behind the decreasing Access-to-Watch ratio observed in this study through the conduct of further studies. This will be important in influencing deliberate policies aimed at reversing the trend towards >60% prescription of antibiotics in the hospital belonging to the Access group.This study showed a sturdy rate of antibiotic consumption over the 6-year study period with a year-on-year decrease in the Access-to-Watch ratio of antibiotics. Amoxicillin-clavulanate, cefuroxime and sulfamethoxazole-trimethoprim were the three most consumed antibiotics; however, clindamycin, amoxicillin-clavulanate and ceftriaxone were the top three antibiotics according to the total budget spent. Data from pharmacy drug issues offer an opportunity to conduct antibiotic surveillance at the hospital level in Ghana and when aggregated may give a national picture. This could be a useful resource for monitoring antibiotic stewardship activities at the hospital and national levels.dlad025_Supplementary_DataClick here for additional data file.


However, the performance of geopolymer concrete is less than that of Portland cement concrete. To improve the performance of geopolymer concrete nano silica was used in the present study. In this work, geopolymer concrete was made utilizing fly ash, ground granular blast furnace slag (GGBS), and sugarcane bagasse ash. In the first instance, binary combinations i.e. fly ash and GGBS were employed as cementitious materials for the production of geopolymer concrete. In the second instance, a ternary mixture of pozzolanic material was prepared by taking 25% GGBS, 65% Fly ash, and 10% bagasse ash. In the third instance, varying percentages of nanoparticles were used for the above ternary mixture. The mechanical and durability properties of the geopolymer composite that was made earlier were tested. The compressive strength and split tensile strength of geopolymer composites were assessed for mechanical properties and a rapid chloride permeability test, water absorption test, and acid attack test were done to know about the porosity of concrete. Results showed that, with a dose of 4% nanoparticles, the durability and strength properties of the concrete had improved the most. The GCBA-N4 mixture had the highest split tensile and compressive strength was measured to be 2.91 MPa and 41.33 MPa and the rapid chloride permeability test, water absorption rate, and percentage of mass loss due to sulfate attack were found as a minimum for GCBA-N4 specimen.Nowadays low calcium fly ash-based geopolymer concrete can be replaced with cement-based concrete to avoid the adverse effect of manufacturing cement on the environment. Utilization of geopolymer concrete instead of traditional concrete using low calcium fly ash and nano silica reduces a significant amount of CO A solution of sodium hydroxide, sodium silicate, and sodium hydroxide or water is used to activate sodium aluminosilicates such as fly ash, granulated blast furnace slag, metakaolin, and volcanic ash to form geo-polymer concrete (GPC). Using geopolymer concrete composites can reduce the amount of heat needed to form early concrete strength, as well as the amount of fly ash and slag cement that must be disposed of in landfills, as well as the amount of CO2 emissions generated by such landfills. Cement paste and aggregates are the primary ingredients in concrete, a cementitious composite. Conventional concrete manufacturing relies heavily on Portland Cement (PC)1. A ton of Portland Cement produces 600 kg to 800 kg of Carbon dioxide based on the amount of CO2 generated per ton of cement produced2. It has also been demonstrated that the price of geopolymer concrete is about the same as that of Ordinary Portland Cement concrete while lowering emissions of carbon dioxide by 22–72%. While using geopolymer concrete instead of Ordinary Portland Cement composites might increase sustainability, geopolymer concrete has proved to have good strength and durability qualities.Geopolymer concrete is considered the next generation of concrete since it eliminates the need for standard Portland cement in its production, hence reducing CO2 emissions into the atmosphere, according to the Environmental Protection Agency (EPA)5. In recent years, geopolymer materials have been the focus of the majority of the study. Geopolymer is an environmentally friendly and highly efficient construction binding material that offers significant environmental benefits over other binding compounds. It is made by reacting with an alumino-silicate source in a high pH environment, which has significant environmental benefits over typical binding chemicals9. For the first time, a new adhesive compound that may be made at low or moderate temperatures has been referred to as “Geopolymer” by Davidovits. It is now the primary focus of geopolymer research and development to create alternative cement manufacturing techniques and cost-effective construction materials. Because geopolymer materials have a lower calcination temperature than conventional procedures, they emit significantly less CO2 than conventional processes.As a result of the high expenses and health risks connected with the disposal of agricultural and industrial wastes such as fly ash, rice husk ash and GGBS in recent years, recycling and reusing of these wastes has become an immensely complicated issue to be addressed. Although their use in cement manufacturing has helped to improve the system performance over the past several decades, the growing demand for the production of cement on a huge scale has piqued the interest of researchers who are concerned about the influence of carbon dioxide emissions on global warming. This represents around 5–8% of overall CO3O4, Fe2O3, and so on), coke, and CaCO3, are heated to a particular temperature of approximately 1500 °C. Since these materials soften in the blast furnace, molten irons are separated from the impurities in the melting process. Those impurities are known as slag. Molten slags are lighter than molten iron, and so molten slags float above the molten iron and are quickly cooled with a high-pressure water jet to form granular particles before being cooled further. After cooling they are fed to a ball mill and ground into a fine powder to produce GGBS15.GGBS is an industrial by-product, produced during the production of steel and iron in the blast furnace, where iron ore To investigate the performance of nano silica on the workability of ternary blended geopolymer concrete.(ii)To investigate the performance of nano silica on the strength of ternary blended geopolymer concrete.(iii)To investigate the performance of nano silica on the durability of ternary blended geopolymer concrete.Geopolymer concrete is an eco-friendly and innovative building material in which the cement is completely replaced by waste pozzolanic materials. Many promising results were shown by conducting a lot of research on high-performance geopolymer concrete, which will give benefit the field of construction engineering. But the utilization of high-performance geopolymer concrete is still in paperwork in most African Countries due to several factors. They may be (i) difficulties for the production of fined pozzolanic materials, (ii) non-availability of mix design process, (iii) non-establishment of practical methods in the field, (iv) not properly utilization of base material, (v) non-availability of equipment for the production of high-performance geopolymer concrete. The above difficulties can be solved by utilizing nano materials in the production of geopolymer to make it efficient. Limited research has been carried out in which nanoparticle are used in geopolymers to increase their performance. Also, many researchers have prepared geopolymer concrete by using a unary or binary combination of pozzolanic materials. But, in the present research, the geopolymer concrete has been prepared by a ternary combination of pozzolanic materials named sugar cane bagasse ash, fly ash and GGBS. Also, limited research had been carried out on the strength and durability of geopolymer concrete with the addition of nano silica. In this research, nano silicas were selected to mix with pozzolanic materials of geopolymer concrete to increase the performance. Various strength and durability properties were checked for new mixes of geopolymer concrete. It was expected that the specific ultra-dense volume, as well as packing density of geopolymer concrete, might be increased due to the addition of nano silica. It will helpful to increase the performance of geopolymer concrete, particularly its strength and durability. It can be noticed that they are very fine particles with granular shapes. Hence, the stiffness of geopolymer concrete might be increased resulting reduction in cracks in concrete structure due to the fineness property of the nano silica. The novelty of the present research is the influence of nano silica on the strength and durability of ternary blending pozzolanic material geopolymer concrete. The objectives of the present research are:–9 m and its SEM image has been shown in Fig. 3 were used as an activator to prepare the geopolymer. The NaOH is available in the market in tablet form. The sodium hydroxide solution was prepared 24 h before the production of concrete by mixing 42 g of NaOH with 1 L water. The ratio between NaOH and CaSiO3 was 1:2.5 the ratio between alkali activator solution to ternary blended pozzolanic material was 1:0.35. A homogenizing procedure was used to improve the dispersion of nanoparticles in the solution. Table Within the scope of this study, eight different concrete mixes were prepared to explore the influence of the nanomaterial and sugarcane bagasse ash (SCBA) on the mechanical properties of the blended geopolymer concrete . Natural fine and coarse aggregates, cementitious materials produced from an alumino-silicate source, a pozzolanic mixture of 65% fly ash (FA), 25% ground granular blast furnace slag (GGBS) and 10% bagasse ash, an alkaline activator, were the main ingredients for the preparation of geopolymer concrete. Mixes that had been combined with nano silica of varying proportions ranging from 0 to 6% as an additive to cement. The granular size of nano silica was 10In the present research, the effect of nano-silica and bagasse ash in fly ash-blast furnace slag-based geopolymer concrete on strength and durability had been studied at a deep level. Here two types of materials were introduced. The first one is bagasse ash, which replaced partially the pozzolanic material up to 10% and the second one was the addition of nano-silica externally to those pozzolanic mixtures up to 6%. Where the pozzolanic material used in geopolymer concrete was a binary blending of fly ash and blast furnace slag. Two types of observations were done in this research. The first one was the action of bagasse ash on the pozzolanic activity for the ternary combination of fly ash, GGBS, and bagasse ash and the second one was the playing role of nano-silica on packing density of geopolymer concrete. For gaining the above knowledge both fresh concrete test and harden concrete test were conducted on new mixed geopolymer concrete and the observed results are discussed below.Relative slump values are based on the flow test with 25 times tamping. This is important to note. Table Figure 40. The formation of C-A-S-H gel took place to a greater extent in the ternary and quaternary blended geopolymer concrete as compared to binary blended geopolymer concrete. The addition of nano-silica helped to form extra C-A-S-H gel by reacting with calcium content in fly ash, resulting in better packing in the matrix. Due to the formation of extra C-A-S-H gel, the microstructure of geopolymer concrete improved. Hence the absorption capacity of the cube had increased by 15%, 12%, and 6% for 7-, 28- and 90-day thermal curing respectively against the compressive strength. From the above results, it was found that the nano-silica had played a better role in gaining the early age strength of concrete.Observing the above figures, it can be seen that the compressive strengths of the GPC with BA and GPC conventional are 43.17 MPa and 44.27 MPa, respectively, after 28 days of thermal curing in the laboratory. The compressive strength had risen by 12% after the addition of one percent of nano-silica particles to the mix. The compressive strength had increased by 16.12% with the addition of 3% nano-silica. In a composite, the proportion of nano silica ready for reaction increased as the volume fraction of nanoparticles in the composite increased. The reaction might proceed much more quickly than in mixes that do not contain nano-alumina. According to the researchers, this could be due to the presence of responsive silica, which controlled the polymerization reaction and promoted the formation of an alumina silica gel, which was required for the nanocomposite’s material strength developmentIncreasing the nano-alumina content above the optimum level, on the other hand, results in a reduction in strength. Excess nano-alumina can aggregate and generate faults in the specimen, such as pores or unreacted particles, which are caused by unreacted components remaining in the specimen after the reaction. The responsible factor for starting decrement in compressive strength beyond the addition of nano-silica as 6% might be the replacement of stronger material (fly ash and GGBS) with the weaker material (bagasse ash) and the absence of pozzolanic activity in ternary mixed concrete. Also, it might be happened due to the un-hydrated cement was coated with extra calcium hydroxide, which was produced due to the addition of nano-silica beyond 4%. Hence, the hydration process might be slow and reduce the strength properties of geopolymer concrete.As shown in Fig. 41 also confirmed similar results that, the tensile strength increased due to the addition of a small amount of nano-silica, but the tensile strength was showing worsen value when higher nano-silica was content. The increase of split tensile strength due to the introduction of nano silica up to 4% and decreased beyond it, happened because of agglomeration. This might be in homogeneity in uncured resin zones, while extra energy was imposed into the mixing process and increased the porosity. By using the nano-silica in geopolymer concrete the water binder ratio was reduced and improved the mortar matrix and interfacial transition zone. This zone became the weakest zone through which cracks was passing through the coarse aggregate particles for the geopolymer concrete in which nano-silica was added more than 4%35.According to Fig. 42. The standard defines degrees of chloride penetration that are evaluated based on the charge transmitted through the specimens being tested. The results revealed that, in general, replacing the binder with Nanosilica enhanced the resistance of the concrete mix to chloride penetration when compared to the conventional mixture. The charge (coulombs) that passed for the control mix (which did not contain any Nanosilica and bagasse ash) was 1071, indicating a very low chloride penetration level. However, as shown in Fig. 16. The influence of nucleation on nanomaterials is responsible for substantial mechanical improvement. Furthermore, a well-dispersed and homogenizednano dispersion may greatly increase particle packing in geopolymer concrete, resulting in a microstructure that appears extremely compacted and dense. Also, the spherical size of nano silica and bagasse ash might be improved the packing density of geopolymer concrete. The passing of coulomb charges through the surface of geopolymer concrete of 90 days cured was less than the 28 days cured geopolymer concrete for every mix containing nano-silica due to the dense microstructure of concrete. The addition of nano-silica reduced the chloride ion penetration in self-compaction as reported by the previous researcher43. This happened due to refined pore structure and densified microstructure. Also, it was reported that the RCPT values of fly ash-based geopolymer mortar with nano silica were reduced due to the presence of more crystalline compounds44. These mechanisms halt fracture formation and act as a bridge between them, inhibiting crack growth. This, in turn, increases the material’s resistance to chloride diffusion.One of the most important elements influencing concrete durability in corrosive conditions is its resistance to chloride penetrationWhen it comes to concrete’s long-term durability, it’s crucial to consider how much water it can absorb. The concrete and structure’s reinforcement both suffer when water gets inside. At present days, water absorption has been considered an important factor for concrete durability, since it measures the transportation of moisture into unsaturated specimens. The water absorption test measures the driving force for the water entry through the concrete surface by both the pressure head and the capillary suction. The water absorption coefficient plays an important role to predict the service life of the concrete structure. The results of a water absorption test are shown in Fig. Figure 2SO4 on the geopolymer concrete specimen, the mass of the concrete specimen reduced gradually as the duration of immersing was increased. The effects of the Na2SO4 attack on the mass loss of geopolymer concrete are shown in Fig. Due to the attack of Na(−10) s and the percentage that has chemically reacted to form CH or become “bound” in the C-A-S-H gel-like structure. From the present research, it was found that, as the percentage of nano silica was increased the percentage of C-S-H gel-like structure increased rapidly and a “bound” like structure formed. Hence the peak of INS spectra for CC was found a lower value and a higher value was found in the GCBA-N6 mix. A new calcium silicate hydrate species that exhibited strong peaking corresponding to the Ca–OH bond, and good coordination between nano silica, sugarcane bagasse ash and fly ash had been developed. The calcium silicate hydrated phase’s molecular and IR spectra both exhibited a peak in that area, which was connected to the translatory movement of calcium hydroxide particles caused by the development of mesopores in sugar cane bagasse ash based concrete i.e. CC to GCBA-N6.Again, the bound hydrogen ratio is the ratio of the initial number of C3S molecules to the number of atoms that have become bound. Because the measured quantity contains both structural water and hydroxyl groups, it can be referred to as “bound hydrogen” rather than “bound water”. The higher percentage of nano silica absorbed more amount of water on its surface, which was utilized in the formation of further C-S-H gel and the formation of more amount of hydroxyl groups. Hence the bound hydrogen was found to double in mix GCBA-N6 mix than the control geopolymer concrete (CC). Since the water-carrying capacity of GCBA-N6 was more than other geopolymer concrete a general tendency was noticed for a higher fraction of hydrogen to become bound. Since more amount of water was absorbed by nano silica and sugar cane bagasse ash, the heat evolved during hydration process was found as lower value. It was noticed that the hydrogen distribution expressed as a function of time as the proportional number of moles of hydrogen atoms associated with each phase. It is evident that as temperature had risen, there was an increase in the amount of unreacted free water. Similar to this, the water content of the C-A-S-H phase, which was formed at higher temperatures, was systematically decreasing for mix of CC and GCBA-N4. The quaternary mix of supplementary cementitious materials which were used for binding materials of geopolymer concrete proved as the best combination for preparing geopolymer concrete and improved the microstructure of concrete significantly. As the percentage of nano silica was increased in geopolymer concrete the peak value inelastic neutron scattering was increased gradually by showing the high thick interfacial transition zone.Inelastic neutron scattering (INS) is an effective approach to study the vibrational properties of substances and gives knowledge about the bonding properties of concrete. This method makes use of the different behavior between free atm and bound atom in the scattering method and uses the gap between the momentum and energy transfer to assemble the vibrational states of the system. A small piece of concrete was taken from each mix and ground into powdered form and produced a paste by adding water. It was spread by taking approximately 8 g of mixed ingredients in a thin 30 × 60 mm layer on an aluminum pan. After weighing it was immediately sealed by an indium gasket. Spectra were taken on an interval of 35 min and were obtained continuously for the first 48 h, then at regular intervals for samples cured at 20 °C. The device was tuned to a scattering angle of 90° with an energy resolution of 3 meV. Reference spectra were measured by placing 3.0 g of pure CH powder in the same cell and constraining it to the same transverse dimension as the sample material. The inelastic neutron spectra obtained from different geopolymer concrete mixes are shown in Fig. The phenomenon of interactions between the incident X-ray beam and the electrons of the atoms of a material component, also known as coherent scattering, is represented by X-ray diffraction (XRD). The technique entails applying radiation to a sample and detecting the photons that are diffracted and make up the diffracted beam. An atom acts as a scattering center when an X-ray beam of a particular frequency focuses on it. The atom vibrates at the same frequency as the incident beam and spreads out in all directions. This incident beam will experience constructive interference in some directions when the atoms are arranged in a lattice, and destructive interference in others. When the path difference between a scattering beam’s successive planes is equal to an integer number of wavelengths, constructive interference of the scattered radiation results.All the concrete samples were grinded to prepare powdered XRD samples. To reduce the sample loss during grinding and to reduce the structural damage to the phases in the sample, they were typically ground under a liquid medium like ethanol or methanol. The ground samples were crystalline powders that have been pressed into the sample holder, had a smooth surface, and were held in at a 45° angle. The film was arranged in a circle around the specimen, which was in the center of the camera. Diffraction occurred and distinctive X-rays were released in conical sections that intersected when a monochromatic X-ray beam was pointed at the specimen and utilized various arcs to expose the film. These arcs appeared as lines when the film was flattened. The distance on the X-ray film between the beam exit and entrance was kept at a 90° Bragg angle. The Bragg angle of each defining line in the film was calculated using the following subsequent ratio.When the refracted Bragg angle was located for each sample, the sample’s crystalline structure was ascertained by considering the crystal’s geometry.The test data of XRD were collected from CuKα radiation of a diffractometer operated at 45 kV and 40 mA. Measurements were taken by making an incident of an X-ray beam on a flat-plate of Bragg–Brentano θ–2θ geometry. Air scatter was reduced with a beam knife and a 1° receive anti-scatter slit was placed in the path of the diffracted beam. A linear position sensing X-ray detector X’Celerator with a length of 2.212° as a 2θ was used for data collection. An angular range of 8° to 60° as 2θ with a 0.017° as 2θ step size was measured from the scanning of all mixes. Fine powder samples of different mixes of concrete were prepared using the backload method and repacked between repeated measurements to minimize the effect of favored orientation. The XRD diffraction test was conducted for evaluation of the crystalline phase and its amount at harden stage after 90 days hydration period. The XRD configuration of traditional concrete and ternary mix of modified concrete are shown in Fig. 6Al6O24)∙8H2O), was found with a distinguishing characteristic between the control geopolymer concrete sample and ternary mixed geopolymer concrete sample with nano silica. This was to be expected as zeolites like hydroxy sodalite were known to be produced during the hydrothermal NaOH treatment of sugar cane bagasse ash with nano silica. It should be noted that the geothermal silica sample (Fly Ash + GGBS + SCBA) exhibited a lot of major peaks. A few numbers of minor peaks were found in mix samples GCC, and GCBA-N4 in areas where sodalite formation was only minor. If the silica disintegrated gradually and the silicate species in solution did not move far from the surface of the particle, this might happen. As a result, some areas were silica-rich i.e. in the GCBA-N6 sample while others were silica-deficient i.e. in the GCC sample. The low silica crystalline hydroxy sodalite phase might form in the silica-deficient gel while the phase-separated system was bound by the higher silicate content X-ray amorphous phase.The presence of C-A-S-H gel was detected in samples containing a mixture of fly ash slag and sugar cane bagasse ash as a precursor from the long peaks that represented the amorphous calcium silicate hydrate matrix. The Calcium Oxide peaks were visible in the XRD results for GCC, GCBA-N4, and GCBA-N6, which was equivalent to the case of SG 100 cured at 40 °C. This occurrence suggests that calcium aluminate silicate hydrate was forming as a result of the hydration of GGBS with nano-silica in the microstructure of the polymer product. The hydration of GGBS with nano silica was thought to resemble the hydration of Portland cement. With a different Ca/Si ratio than control geopolymer concrete (GCC), it led to the formation of a calcium silicate hydrate matrix. This hydration occurred concurrently with the polymerization processes connected to the alkali activation of fly ash and sugar cane bagasse ash. The formation of hydroxy sodalite, a low silica zeolite (Na6(Si(i)The performance of geopolymer concrete prepared from a ternary combination of pozzolanic materials  was better than the binary combination (i.e. fly ash and GGBS) based geopolymer concrete. The addition of bagasse ash prepared secondary C-A-S-H gel, which improved the strength and durability properties.(ii)The addition of nano-silica to the ternary combination-based geopolymer concrete up to 6%, improved the packing density and accelerated the performance at a faster rate.(iii)As the content of nano silica was increased up to 6%, the consistency of geopolymer concrete was increased. The ball bearing action of nano silica improved the mobility of geopolymer concrete showing the highest slump value.(iv)The strength and durability of the nanoparticles incorporated in geopolymer concrete specimens got the better result as the nanoparticle’s dosage varied from 1 to 4%. The geopolymer concrete composite that was made by a ternary combination of fly ash, GGBS, and sugar cane bagasse ash with 4% nanoparticles had shown the best test results for both compressive strength and split tensile strength after 7-days and 28-days curing.(v)RCPT values of ternary combination geopolymer concrete with 4% nano-silica were very low for both 28-days and 90-days curing. The penetration of coulomb charge in the nano-silica mixed geopolymer concretes was observed lesser value than the binary combination of geopolymer concrete. The reduction of chloride ion penetration might be due to the incorporation of spherical particles of nano-silica, which improved the packing density of concrete.(vi)Water absorption value of the ternary combination of geopolymer concrete reduced with increasing nano silica content. This happened due to the combined action of acceleration of the hydration process and pore fillings by extra C-A-S-H gel by which the geopolymer concrete became more compact and denser.(vii)The improvement of surface microstructure in a ternary combination of geopolymer concrete with 4% or above of nano silica was too appreciable. All the mixes containing above 4% of nano silica protected geopolymer concrete from sulphate attack and reduced the percentage of mass loss in a satisfactory manner.The effect on the strength and durability of geopolymer concrete composites with different amounts of nanoparticles was studied. Following are the findings of this study.


A high acoustic emission energy of 1300 nVs is observed at the centre of the beam. Based on the results, the behaviour of the steel in the concrete beam can be determined by the integrity assessment of a structure.The behaviour of the steel bar in concrete under cyclic loading has been evaluated using magnetic flux leakage associated with acoustic emission monitoring technique. Visual observation was used to observe the deformation of the beam under cyclic loading. The sensors of metal magnetic memory were scanned in the middle of the beam at a distance of 320 mm at the bottom part. Twenty-two cyclic ranges were performed for cyclic loading of 100 or 200 cycles for each range, with a frequency of 1 Hz and a sinusoidal wave mode. The magnetic flux leakage signal, acoustic emission characteristics and crack width were measured and analysed to evaluate the behaviour of the steel bar in the concrete beam. The magnetic flux leakage signal and acoustic emission energy results were well matched with the occurrence of cracks at the centre of the beam. It was found that the relationship between the magnetic leakage flux signal and crack opening showed a strong correlation with R The behaviour and integrity of the steel embedded in concrete plays a crucial role in ensuring that the two materials can work together. The combination of these two materials is the most widely used in construction worldwide, as it has excellent mechanical performance due to the high compressive strength of the concrete and the excellent tensile strength of the reinforcing steel ,2,3. As As RC structure is a popular material in construction, e.g., for building bridges and carriageways for high-speed railways and dams, they are subjected to cyclic loads during their service life. This type of loading affects the performance and integrity of the structures as the performance decreases . The effMost studies on the behaviour of steel in concrete are based on the bond between these two materials under pull-out ,12,13,14Magnetic flux leakage (MFL) is a passive NDT technique based on magneto-mechanical effects. MFL has been used extensively to detect corrosion on steel strands , to evalAlthough the MFL technique is extensively used for detection damage of ferromagnetic materials, the use of this technique on detection fatigue damage of reinforced concrete structures is now starting to be reported, for example, by Xie et al., who fixed the MMM in specific locations . They inThe aim of this study is to experimentally investigate the behaviour of steel bars embedded in concrete under cyclic loading, using the MMM and verified by acoustic emission technique. It was taken into consideration that the embedded steel bar was 20 mm from the bottom section or the tensile part of the beam. The MMM sensor was used to scan the soffit of the beam when the cyclic load stopped for specific load cycles. Meanwhile, the acoustic emission was used to monitor any displacement that occurred during testing. Then, equations between the magnetic flux leakage, acoustic emission characteristics and the crack opening were proposed. This study is significantly beneficial for predicting the behaviour of the steel bar in the concrete during service and for helping to maintain the integrity of the RC beam. Early detection of the condition of the concrete and the steel in the concrete can help to maintain the performance of the structure as a whole, especially for infrastructures such as bridges, which are subjected to cyclic loads as vehicles cross the bridge. Since the strength of the structures is highly dependent on the strength of the steel, the magnetic flux leakage associated with the acoustic emission technique is a useful tool to determine the flaw of the steel at an early stage, which eventually may lead to crack and final fracture.2 > 0.8) [The process flow of evaluation of the behaviour of the steel bar in a concrete beam using the MMM method is presented in 2 > 0.8)  between A total of six reinforced concrete beams were prepared. The high strength steel bar of 10 mm (T10) diameter was used in this study. Two types of tests were performed, i.e., a static test and a cyclic test. The static test with 3-point bending was performed to determine the ultimate load of the beam with a constant loading rate of 1 mm/min according to ASTM C78 . From thThe cyclic test was based on a constant amplitude loading pattern with 100 or 200 cycles for 2 min at the frequency of 1 Hz until the specimens failed. The acoustic emission was applied to monitor the occurrence of damage that appeared on the beam surface. It was performed in conjunction with cyclic loading for each load range. The machine was stopped every 100 or 200 cycles see  to measuThe cyclic loading arrangements as set in The MMM method was used to measure the performance of the steel bar in concrete when the beam is subjected to cyclic loading. This method, based on the measurement of magnetic signals on the surface of the specimen, is a non-destructive test and can be used to track and monitor the fatigue growth failure of the specimen . Using tThe MMM was based on the magnetometric stress concentration test set (TSCM) as shown in In this study, the magnetic signal is observed at no load, from the beginning of the test, during the ongoing test and until the samples fail. The scanning at no load was carried out to observe the influence of the environmental magnetic field on the results . The posFor the acoustic emission monitoring, four sensors, type VS75-V, which have a peak frequency of 75 kHz and pass-band of 30–120 kHz, were coupled on the beam at a specific location. The high vacuum grease was used as a coupling between the sensor surface and the beam surface. Two sensors were coupled on top of the beam, designated as CH1 and CH2 and located at 217.5 mm and 532.5 mm from the edge of the beam, as shown in The crack width on the beam surface was measured with the digital caliper when the machine stopped. The crack propagation was then recorded, and a torch was used to observe the appearance of the hairline crack on the beam surface. Meanwhile, the signal of magnetic flux leakage obtained by the MMM method was analysed to determine the area of stress concentration and the location of crack initiation and its growth. The characterisation of the magnetic signals is the gradient signal of the normal component, dh(y)/dx with a fatigue growth parameter in a stable crack growth region. The dh(y)/dx signal is used in crack growth analysis compared to the H(y) signal because the dh(y)/dx signal is more sensitive to the degree of damage to the sample . HoweverThe magnetic signal triggered by the ferromagnetic bar undergoing crack growth was recorded. The variation of the magnetic signal value is a function of the concentration area experienced by the beam under cyclic loading. The characterisation between the magnetic signal parameters is based on the crack growth areas at the scan line, as shown in The changes in the signals show the evolution of the crack in the sample . It can 2 of 0.9725. When the R2 is above 0.9, this indicates a strong correlation between the two variables. The correlation of the magnetic flux leakage and the cycles is presented in Equation (1).The continuous cyclic loading increases the crack opening by 0.18 mm at 100 to 200 cyclic loadings b. Crack 2 value of 0.99 between the crack width and the load cycles. The correlation is based on the linear best fit plot, and the equation of this correlation is presented in Equation (2).2 of 0.969. Hence, from this correlation, Equation (3), based on the magnetic flux signal and the crack opening, was proposed as follows:This correlation is useful for estimating the integrity of the beam, especially as it relates to the cracking and behaviour of the steel bar in the concrete. The prediction of the crack growth from the initiation of the crack in the concrete until failure can be made. The behaviour of the steel bar in the concrete can also be estimated using the equation pronounced by the relationship between magnetic flux leakage signal and crack opening.The same activities can also be observed by looking at the relationship between amplitude and locations, as can be seen in 2 of 0.9725, as the steel bar in the concrete continuously deforms as the cyclic load continuously acts on the beam.The magnetic leakage flux signal results from the Hp-2 signal values show high stress concentration zones in the range of 147 mm to 189 mm, which represent the low peak value of the magnetic leakage flux signal. As the load increases, the signal pattern in the critical region takes on a convex shape, which produces a strong correlation R2 of 0.99 for beam FT10 shows a strong correlation between crack width and load cycles. An equation between magnetic flux leakage and crack opening with an R2 of 0.969 was proposed.The relationship between crack opening and load cycles with an RA high acoustic emission energy and amplitude with a value of 1310 eu and 74 dB can be detected at a distance of 389 mm from the left side of the beam, as the crack occurred at this position and the MMM provided a low vortex signal.The study is of importance for understanding the behaviour of steel bars in concrete, as it is difficult to assess the behaviour of steel bars, especially under load, by visual observation. This study is useful for predicting the fatigue life of structures subjected to cyclic loading.