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Abstract Improper waste management is causing global environmental problems. Waste glass may have adverse impacts on the ecosystem. While a substantial amount of soda-lime glass bottle (SGB) undergoes recycling to create new glass items, a significant volume still ends up in landfills. Therefore, the aim of this study was to explore the potential use of SGB in foamed concrete (FC) production as an aggregate replacement. SGB was substituted for sand in different weight fractions, ranging from 5 to 50%. The fresh state, mechanical, thermal, pore structure, and transport properties were examined. The findings showed a significant enhancement in the FC’s mechanical properties when SGB replaced 20% of sand. The compressive, flexural, and splitting tensile strengths exhibited a rise of up to 17.7, 39.4, and 43.8%, respectively. The findings also demonstrated that the addition of SGB improved the thermal conductivity, sorptivity, water absorption, and porosity. The scanning electron microscopy analysis indicated that the inclusion of 20% SGB caused a substantial decrease in void diameter and enhanced its uniformity. A comparison was made between the experimental data and predictions of the mechanical properties using various models of international standards, such as IS 456, ACI 318, NZS-3101, EC-02, AS 3600, and CEB-FIB, along with several references in the literature. The findings implied a strong correlation between the strength properties. The outcomes of this research offer valuable insights into both the possible advantages and constraints of using SGB in FC. Furthermore, this extensive laboratory investigation may serve as a guideline for future study and aid in the advancement of greener and more environmentally friendly FC alternatives.

Over the last few decades, researchers have devoted significant consideration to the use of nanoscale elements in concrete. Silicon dioxide nanoparticles (SDNs) have been a popular subject of study among the several types of nanoparticles. This article describes the findings of a laboratory investigation that examined the properties of ultra-lightweight foamed concrete (ULFC) including different proportions of SDNs. Wide range of the properties was evaluated specifically the slump flow, density, consistency, flexural strength, modulus of elasticity, compressive strength, split tensile strength, thermal properties, porosity, water absorption, sorptivity, intrinsic air permeability, and chloride diffusion. Additionally, the scanning electron microscopy (SEM) and pore distributions analyses of different mixes were done. Results confirmed a noticeable increase in the mechanical properties of ULFC, with respective improvements in the 28-day compressive, split tensile, and flexural strengths of up to 70.49%, 76.19%, and 51.51%, respectively, at 1.5% of the SDNs inclusion. However, further increases in the SDNs percentage did not result in remarkable enhancements. As the SDN percentage increased from 1.5% to 2.5%, the ULFC's sorptivity, porosity, water absorption, intrinsic air permeability, and chloride diffusion showed substantial improvements. When compared to the control sample, ULFC with SDNs demonstrated higher thermal conductivity values. The reason for this occurrence was determined to be the smaller pore size observed in the ULFC specimens containing SDNs. A great adjustment in the distribution of pore diameters was witnessed in the ULFC mixes when the percentages of SDNs were adjusted. The ULFC specimens, which included SDNs at the percentages of 0.5%, 1.0%, and 1.5%, indicated a reduction in the total number of large voids measuring 500 nm or more, compared to the control ULFC specimen. The findings of this study highlight the potential benefits of incorporating SDNs into ULFC, which may improve its overall properties.

Three different densities (500 kg/m3, 1000 kg/m3, and 1500 kg/m3) of foamed concrete (FC) were tested alongside mortar with a density of 1980 kg/m3 to investigate how high temperatures affect the qualities of FC. A flow table test was used to examine the fresh qualities of the mixtures. The modulus of elasticity, ultrasonic pulse velocity (UPV), bending strength, split tensile strength, compressive strength, thermal conductivity, porosity, and appearance and colour changes at ambient temperature and after exposure to various high temperatures (100 °C, 150 °C, 200 °C, 400 °C, 600 °C, and 800 °C) were evaluated. To study the effects of varying densities, microstructure analysis was performed utilizing scanning electron microscopy and mercury intrusion porosimetry. According to the findings, the four varied densities appeared dissimilar. FC with lower densities (500 kg/m3 and 1000 kg/m3) showed signs of cracking, while FC with a higher density (1500 kg/m3) enabled for precise detection of the pore connectivity and surface spalling occurrences. High temperatures had less effect on the mortar than FC mixtures. As the temperature increased, the modulus of elasticity, split tensile strength, bending strength, compressive strength, thermal conductivity, and mass loss decreased for all the mortar and FC samples. The UPV values increased marginally up to 100 °C before decreasing. This investigation highlighted the need for additional research and code provisions that consider different innovative construction materials and FC constituent classes.

Nowadays, special concrete-like self-compacting concrete (SCC) requires sustainability by introducing recycled aggregates as a partial replacement for natural aggregate. Technological development initiatives in the construction sector estimate the 28 days' concrete compressive strength before casting due to faster requirement; one method selected is an artificial neural network. From works of literature, 515 mixed design are collected and utilized for training, validation, and testing data to prepare models. Different applications of SCC require different strengths of concrete. Based on control mix compressive strength, the mix designs are grouped into three families as low, medium, and high strength, apart from a common family. The correlation between input and output variables for three different families is analyzed. ANOVA analyses are done for input parameters. Coefficient of relation (R2) is used for sensitive assessment and results for family I (R2 = 0.9299), family II (R2 = 0.824), family III (R2 = 0.8775), and family IV (R2 = 0.7991). Two further sensitivity analyses indicate that input parameters' influence varies for different families.

Nowadays, the application of nanotechnology has gained increased attention in the concrete technology field. Several applications of concrete require light weight; one such concrete used is foamed concrete (FC), which has more voids in the microstructure. In this study, nano-silica (NS) was utilized, which exhibits a pozzolanic nature, and it reacts with other pozzolanic compositions (like lime, alumina, etc.) to form hydrated compounds in concrete. Apart from these hydrated compounds, NS acts as a filler material and enhances properties of concrete such as the fresh and hardened properties. This research examines the fresh, hardened, and microstructural properties of FC blended with NS. The ratio of binder and filler used in this research is 1:1.5, with a water-to-binder ratio of 0.45 and a density of 880 kg/m3. A total of six different weight fractions of NS were added to FC mixes, namely 0%, 1%, 2%, 3%, 4%, and 5%. Properties assessed for FC blended with NS were the slump, bulk density, strength parameters (flexural, splitting tensile, and compressive strengths), morphological analysis, water absorption, and porosity. It was concluded from this study that the optimum NS utilized to improve the properties was 3%. Apart from this, the relationship between the mechanical properties and NS dosages was developed. The correlations between the compressive strength and other properties were analyzed, and relationships were developed based on the best statistical approach. This study helps academicians, researchers, and industrialists enhance the properties of FC blended with NS and their relationships to predict concrete properties from other properties.

Researchers have shown significant interest in the incorporation of nanoscale components into concrete, primarily driven by the unique properties exhibited by these nanoelements. A nanoparticle comprises numerous atoms arranged in a cluster ranging from 10 nm to 100 nm in size. The brittleness of foamed concrete (FC) can be effectively mitigated by incorporating nanoparticles, thereby improving its overall properties. The objective of this investigation is to analyze the effects of incorporating calcium carbonate nanoparticles (CCNPs) into FC on its mechanical and durability properties. FC had a 750 kg/m3 density, which was achieved using a binder-filler ratio of 1:1.5 and a water-to-binder ratio of 0.45. The CCNPs material exhibited a purity level of 99.5% and possessed a fixed grain size of 40 nm. A total of seven mixes were prepared, incorporating CCNPs in FC mixes at the specific weight fractions of 0% (control), 1%, 2%, 3%, 4%, 5%, and 6%. The properties that were assessed included the slump, bulk density, flexural strength, splitting tensile strength, compressive strength, permeable porosity, water absorption, drying shrinkage, softening coefficient, and microstructural characterization. The results suggested that incorporating CCNPs into FC enhanced its mechanical and durability properties, with the most optimal improvement observed at the CCNPs addition of 4%. In comparison to the control specimen, it was witnessed that specimens containing 4% CCNPs demonstrated remarkably higher capacities in the compressive, splitting tensile, and flexural tests, with the increases of 66%, 52%, and 59%, respectively. The addition of CCNPs resulted in an improvement in the FC porosity and water absorption. However, it also led to a decrease in the workability of the mixtures. Furthermore, the study provided the correlations between the compressive strength and splitting tensile strength, as well as the correlations between the compressive strength and flexural strength. In addition, an artificial neural network approach was employed, utilizing k-fold cross-validation, to predict the compressive strength. The confirmation of the property enhancement was made through the utilization of a scanning electron microscope.

In this study, waste marble powder (WMP) was used to replace cement of concrete in specific amounts. To accomplish this aim, WMP was replaced at 10%, 20%, 30%, and 40% of the cement weight, and a reference concrete sample without WMP (REF) was created to compare the compressive strength, splitting tensile strength, and flexural strength. The replacement of WMP at 10%, 20%, 30%, and 40% of the cement weight resulted in 5.7%, 21.7%, 38.1%, and 43.6% decreases in the compressive strength compared with REF. Furthermore, the splitting tensile strength results commonly followed the same trend as the compressive strength. However, WMP at 10%, 20%, 30%, and 40% led to 5.3%, 8.6%, 19.4%, and 26.7% decreases in the flexural strength compared with REF. In addition, three different calculations, ranging from simple to complex, were proposed to compute mechanical resistances of concrete with WMP. These proposed calculations for practical applications were validated using values from the literature and the implications obtained from the current research. While the simple calculations were based on the strength of REF and the WMP percentages, the complex calculations were dependent on the design of the concrete mixture, age of the samples, and the WMP percentages. For the complex calculations, the ANN approach was used with the help of the coefficient of determination (R2) for the K-fold cross validation method. All the proposed methods provided high accurate estimation to predict the properties of concrete with WMP. Based on the studies, utilizing 10% WMP as the replacement of cement is recommended to obtain the optimum benefits considering both mechanical and environmental aspects. Moreover, scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analyses were then conducted to observe the interaction of WMP in concrete. According to the SEM analyses, some pores were detected and the interfacial transition zone was observed in the reaction zone. On the other hand, based on the EDX analyses, the presence of WMP in concrete was manifested by the presence of high levels of calcium.

The requirement of the construction sector pushes researchers and academicians to determine the 28-day concrete compressive strength due to less consumption of natural products and reduced cost. One recommended method to reduce the cost and simultaneously adopt sustainability is introducing recycled aggregates in concrete. Most typical structures require concrete, which is self-flowable and compactable; specific structures require concrete, which is self-flowable and compactable; one such concrete is self-compacting concrete (SCC). 515 mix design samples for SCC with recycled aggregates are collected from the literature and used for training, validation, and testing to create the model using machine learning techniques (Extra Gradient (XG) Boosting, Ada Boosting, Gradient Boosting, Light Gradient Boosting, Category Boosting, K Nearest Neighbors, Extra Trees, Decision Trees, Random Forest, and Support Vector Machine). The correlation between input and output variables is analyzed using ANOVA and is indicated that data can be used to develop machine learning models successfully. Sensitive analysis and error assessment are performed to choose the best machine learning methods, and it found that CB, KNN, and ERT have the highest R2 value and lowest MSE.

There is much agriculture and non-agricultural waste that contains pozzolanic material, which can be recommended to use as a partial replacement for Ordinary Portland Cement (OPC). One of the waste products from sugar industries, which possess pozzolanic properties, is Sugar Cane Bagasse Ash (SCBA). Because of the negative impact associated with cement production, OPC is being replaced by several supplementary cementitious materials / pozzolanic materials. In the current study, an effort has been made to use the SCBA by partially replacing the OPC for mortar studies. SCBA has been processed to enhance the chemical and physical properties. OPC is partially replaced by Processed Sugar Cane Bagasse Ash (PSCBA) up to 30% by a 5% increment. PSCBA blended cement mortar contains different proportions of PSCBA blended cement: river sand as 1:3, 1:4, and 1:5 with different water-to-binder (W/B) ratios based on the flow studies. Experimental research was done to determine the effects of the W/B ratio, river sand, and PSCBA on the formation of the cube compressive strength of PSCBA blended cement mortar for curing times of 7, 14, 28, 56, and 112 days. An increase in compressive strength about 6.4%, 9.3%, and 8.2% for 1:3, 1:4 and 1:5 with different W/B ratios for 28 days is reported. Based on the investigational results, the coefficients of strength for various relationships proposed by different researchers have been calculated for the binder: sand ratio as 1:3 and 28 days curing period. Various relationships, including Abraham, Feret, Singh, and Bolomey law are used to validate the mixes of the PSCBA blended cement for different water-to-binder ratios and different curing periods. A novel relation has been developed through the extension of studies to forecast the compressive strength of PSCBA blended mortar mixes with various W/B ratios for various curing times.

When a seismic load is applied horizontally or laterally on unreinforced masonry walls (URM), the walls behave in two different ways, viz., in-plane (IP) and out-of-plane (OoP). This review beneficially provides a literature overview of the most cited research papers on Scopus, and the database is evaluated with VOSviewer software for scientometric analysis. This review paper delves into the practical applications of various types of reinforcement for masonry walls, specifically focusing on four commonly used systems: externally bonded strengthening techniques using fiber-reinforced polymers (FRP), steel-reinforced grout (SRG), fabric-reinforced cementitious mortar (FRCM), and textile-reinforced mortars (TRM). The main objective of the paper is to explore the efficacy of these reinforcement techniques in strengthening masonry walls, and to provide a comprehensive overview of their respective advantages and limitations. A further detailed study of the extent of the literature is performed about the effect of the different strengthening systems on the mechanical properties of different categories of masonry walls like a cement block, stone, and clay brick are described and categorized. The efficiency of OoP strengthening can depend on various factors, such as the types of masonry units, the rendering mortar, the type of strengthening system, the bond between the different materials interfaces, the geometry of the wall, and the loading conditions. By utilizing the practical method of Dematel (Decision-making trial and evaluation laboratory) analysis, this review can delve deeply into the impact of various factors and precisely identify the crucial components of the cause-and-effect connection. The results indicate that the bond between material interfaces is the critical factor. This meticulous and structured review offers valuable perspectives for researchers and engineers, showcasing current research trends and presenting potential avenues for future exploration.

Competitive advantage significantly matters for modern construction organizations as it promotes the sustainable development and safety management of projects. UK construction organizations have greatly suffered from a lack of safety and sustainability of project management in infrastructure development projects because of the COVID-19 pandemic. Post-COVID-19 UK infrastructure development projects are uncertain in the context of organizational competitive advantage as they cannot maintain sustainable project management. This study was conducted to identify, rank, and present a framework of factors influencing the competitive advantage of UK organizations. The study design involved identifying factors from the current literature, after which the most relevant factors were filtered with the help of semi-structured interviews with 15 experts. A pilot survey was conducted then, involving 192 respondents, after which a reliability test and exploratory factor analysis (EFA) were conducted on the results. A primary questionnaire survey involving 250 respondents was conducted, after which RII and confirmatory factor analysis (CFA) were conducted on the final data. A total of five subgroups were found to be significant in the CFA, such as Resources and Policies, Quality and Delays, Motivation and Expectation, Management and Environment, and Government and Business. It is recommended based on findings that the construction organizations of the UK have to consider working on identified factors to maintain a competitive advantage in establishing sustainable project management solutions for post-COVID-19 UK infrastructure development projects.

In the present era of architecture, different cross-sectional shapes of structural concrete elements have been utilized. However, this change in shape has a significant effect on load-carrying capacity. To restore this, the use of column confinements with elliptical sections has gained attention. This paper aim to investigate the effect of elliptical shape sections of confined concrete reinforced with Carbon Fiber Reinforced Polymer (CFRP) and steel tube on axial load-carrying capacity. This study is achieved using following tools Finite Element (FE) in Abaqus and Artificial Neural Networks (ANN) modeling. The study involved a 500-mm-high column with three sets of aspect ratios: 1.0, 1.5, and 2.0. In each aspect ratio, three different layers of CFRP were used, i.e., .167, .334, and .501-mm. Analytical results showed that with the increase in aspect ratio from 1 to 2, there is a decrease in ultimate axial load of about 23.2% on average. In addition, the combined confining pressure of steel tube and CFRP increases with a decrease in dilation angle as the number of CFRP layers increases. The failure mode for the column with a large aspect ratio is local buckling at its mid-height along the minor axis. The result showed a good correlation between FE and experimental results of ultimate stress and strains, with a mean squared error of 2.27 and .001, respectively. Moreover, ANN and analytical models showed a delightful correlation of R2 of .97 for stress models and .88 for strain models, respectively. The elliptical concrete section of the column confined with steel tubes can be adopted for a new architectural type of construction; however, with more than three aspect ratios, the wrapping of the section with CFRP jackets is highly recommended.

This article examines the performance of Carbon Fibre Reinforced Polymer (CFRP) on Concrete Filled with Polymer Vinyl Chloride Tube (CFPT) columns under axial compression. Firstly, 44 CFPT specimens from the literature were analyzed using ABAQUS software to understand the compressive behavior of specimens under applied displacement. Secondly, 268 CFPT specimens are simulated to understand the influence of CFRP on these control specimens with a varying number of FRP layers and wrapping depth. Other variables such as the unconfined concrete strength, the thickness of the PVC tube, and the size and slenderness ratio of the columns were also studied. Studies are extended to confinement damage plasticity model analysis of CFRP-CFPT (CCFPT) columns. Relationships between the load-carrying capacity of CCFPT columns and the CFRP properties were developed. The effect of these parameters on the CFPT leads to the development of analytical models. It is an advantage to applying a such new type of composite columns in various applications.

Larger consumption of natural fine aggregates (NFA) leads to an increase in cost, energy, and negative environmental impact. On the contrary, the larger production of construction waste results in the generation of recycled fine aggregate (RFA), which requires safe disposal. The aim of study, is to the hunt for such alternatives, compares the mortar mechanical and durability properties with and without RFA. High strength mortar specimens were produced with mix proportion as 1:3 using RFA as partial replacement for NFA as 0%, 25%, 50% and 100%. The mechanical and durability performance of all specimens was assessed in the terms of compressive strength, flexural strength, water absorption and mercury intrusion porosimetry. Mechanical performance is confirmed by microscopic studies. The main results display that the mortar with 25% of RFA, performed better, which are related to pore structures and their distribution. It is noted that the, pores also increase with the increase in RFA content. The effect of pores on the strength and their relationships are assessed.

A main global challenge is finding an alternative material for cement, which is a major source of pollution to the environment because it emits greenhouse gases. Investigators play a significant role in global waste disposal by developing appropriate methods for its effective utilization. Geopolymers are one of the best options for reusing all industrial wastes containing aluminosilicate and the best alternative materials for concrete applications. Waste wood ash (WWA) is used with other waste materials in geopolymer production and is found in pulp and paper, wood-burning industrial facilities, and wood-fired plants. On the other hand, the WWA manufacturing industry necessitates the acquisition of large tracts of land in rural areas, while some industries use incinerators to burn wood waste, which contributes to air pollution, a significant environmental problem. This review paper offers a comprehensive review of the current utilization of WWA with the partial replacement with other mineral materials, such as fly ash, as a base for geopolymer concrete and mortar production. A review of the usage of waste wood ash in the construction sector is offered, and development tendencies are assessed about mechanical, durability, and microstructural characteristics. The impacts of waste wood ash as a pozzolanic base for eco-concreting usages are summarized. According to the findings, incorporating WWA into concrete is useful to sustainable progress and waste reduction as the WWA mostly behaves as a filler in filling action and moderate amounts of WWA offer a fairly higher compressive strength to concrete. A detail study on the source of WWA on concrete mineralogy and properties must be performed to fill the potential research gap.

A considerable amount of discarded building materials are produced each year worldwide, resulting in ecosystem degradation. Self-compacting concrete (SCC) has 60–70% coarse and fine particles in its composition, so replacing this material with another waste material, such as recycled aggregate (RA), reduces the cost of SCC. This study compares novel Artificial Neural Network algorithm techniques—Levenberg–Marquardt (LM), Bayesian regularization (BR), and Scaled Conjugate Gradient Backpropagation (SCGB)—to estimate the 28-day compressive strength (f’c) of SCC with RA. A total of 515 samples were collected from various published papers, randomly splitting into training, validation, and testing with percentages of 70, 10 and 20. Two statistical indicators, correlation coefficient (R) and mean squared error (MSE), were used to assess the models; the greater the R and lower the MSE, the more accurate the algorithm. The findings demonstrate the higher accuracy of the three models. The best result is achieved by BR (R = 0.91 and MSE = 43.755), while the accuracy of LM is nearly the same (R = 0.90 and MSE = 48.14). LM processes the network in a much shorter time than BR. As a result, LM and BR are the best models in forecasting the 28 days f’c of SCC having RA. The sensitivity analysis showed that cement (28.39%) and water (23.47%) are the most critical variables for predicting the 28-day compressive strength of SCC with RA, while coarse aggregate contributes the least (9.23%).

Several types of research currently use machine learning (ML) methods to estimate the mechanical characteristics of concrete. This study aimed to compare the capacities of four ML methods: eXtreme gradient boosting (XG Boost), gradient boosting (GB), Cat boosting (CB), and extra trees regressor (ETR), to predict the splitting tensile strength of 28-day-old self-compacting concrete (SCC) made from recycled aggregates (RA), using data obtained from the literature. A database of 381 samples from literature published in scientific journals was used to develop the models. The samples were randomly divided into three sets: training, validation, and test, with each having 267 (70%), 57 (15%), and 57 (15%) samples, respectively. The coefficient of determination (R2), root mean square error (RMSE), and mean absolute error (MAE) metrics were used to evaluate the models. For the training data set, the results showed that all four models could predict the splitting tensile strength of SCC made with RA because the R2 values for each model had significance higher than 0.75. XG Boost was the model with the best performance, showing the highest R2 value of R2 = 0.8423, as well as the lowest values of RMSE (=0.0581) and MAE (=0.0443), when compared with the GB, CB, and ETR models. Therefore, XG Boost was considered the best model for predicting the splitting tensile strength of 28-day-old SCC made with RA. Sensitivity analysis revealed that the variable contributing the most to the split tensile strength of this material after 28 days was cement.

One of the prime objectives of this review is to understand the role of design parameters on the mechanical properties (Compressive and split tensile strength) of Self-Compacting Concrete (SCC) with recycled aggregates (Recycled Coarse Aggregates (RCA) and Recycled Fine Aggregates (RFA)). The design parameters considered for review are Water to Cement (W/C) ratio, Water to Binder (W/B) ratio, Total Aggregates to Cement (TA/C) ratio, Fine Aggregate to Coarse Aggregate (FA/CA) ratio, Water to Solid (W/S) ratio in percentage, superplasticizer (SP) content (kg/cu.m), replacement percentage of RCA, and replacement percentage of RFA. It is observed that with respect to different grades of SCC, designed parameters affect the mechanical properties of SCC with recycled aggregates.

Most concrete studies are concentrated on mechanical properties especially strength properties either directly or indirectly (fresh and durability properties). Hence, the ratio of split tensile strength to compressive strength plays a vital role in defining the concrete properties. In this review, the impact of design parameters on the strength ratio of various grades of Self-Compacting Concrete (SCC) with recycled aggregate is assessed. The design parameters considered for the study are Water to Cement (W/C) ratio, Water to Binder (W/B) ratio, Total Aggregates to Cement (TA/C) ratio, Fine Aggregate to Coarse Aggregate (FA/CA) ratio, Water to Solid (W/S) ratio in percentage, superplasticizer (SP) content (kg/cu.m), replacement percentage of recycled coarse aggregates (RCA), replacement percentage of recycled fine aggregates (RFA), fresh density and loading area of the specimen. It is observed that the strength ratio of SCC with recycled aggregates is affected by design parameters.

This article presents an overview of the bibliographic picture of the design parameter’s influence on the mix proportion of self-compacting concrete with recycled aggregate. Design parameters like water-cement ratio, water to paste ratio, and percentage of superplasticizers are considered in this review. Standardization and recent research on the usage of recycled aggregates in self-compacting concrete (SCC) exploit its significance in the construction sector. The usage of recycled aggregate not only resolves the negative impacts on the environment but also prevents the usage of natural resources. Furthermore, it is necessary to understand the recycled aggregate property’s role in a mixed design and SCC properties. Design parameters are not only influenced by a mix design but also play a key role in SCC’s fresh properties. Hence, in this overview, properties of SCC ingredients, calculation of design parameters in mix design, the effect of design parameters on fresh concrete properties, and the evolution of fresh concrete properties are studied.