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To study the enhancement effect of carbon nanotubes (CNTs) on the splitting tensile properties of foamed concrete backfill in which cement and fly ash were used as the cementitious materials and natural sand was used as the aggregate, specimens of CNT-modified foamed concrete backfill were prepared. Brazilian splitting tests were used to investigate the splitting tensile strength of the CNT-modified foamed concrete backfill, and the digital speckle correlation method was used to analyze the stress field characteristics and crack expansion law of the specimens during splitting tensile testing. The stress–strain characteristics and energy dissipation laws of the backfill were studied at various static loading rates, and a relationship between the splitting tensile strength, ultimate strain, and loading rate was established. The results showed that at the optimum CNT content of 0.05%, the peak strength and ultimate strain of the modified foamed concrete backfill increased by an average of 67.2% and 21.7%, respectively. Moreover, after modification with CNTs, the foamed concrete backfill was less likely to develop strain concentration areas before reaching peak strength. The triangular stable loadbearing structure formed by the modified foamed concrete backfill after splitting caused the end of the stress–strain curve to exhibit varying degrees of "backlash". For the CNT-modified foamed concrete backfill, the peak strength correlated logarithmically with the loading rate, while the ultimate strain correlated as a power function of the loading rate. At a low loading rate, the CNT-modified foamed concrete backfill dissipated less energy, and the reverse was true for higher rates. [ABSTRACT FROM AUTHOR]

In recent years, mortar bricks or autoclaved aerated concrete (AAC), also known as foamed concrete, have been widely used as masonry wall materials. Foamed concrete, like bricks, can be produced by adding a foaming agent to achieve the desired weight and density, while meeting requirements for strength and durability. However, the search for sustainable construction materials has become imperative, including the use of waste materials to partially replace cement. The incorporation of SCM in the production of cement-based materials, such as foamed concrete, has a significant impact on reducing CO2 emissions and promoting a sustainable environment. POFA, a secondary product derived from the palm oil industry that is typically left on the ground, poses environmental problems. Due to its good performance and pozzolanic reactions, POFA-based construction materials have great potential as alternatives to ordinary Portland cement. Unlike previous studies, this research evaluates the strength and durability of foamed concrete with variations in foam agent dosages, including finer particles of POFA (100µm) as a partial cement replacement. The study produced a total of 6 batches of foamed concrete, measuring compressive strength, porosity, water absorption, and electrical resistivity. Additionally, the research examined the correlation between compressive strength and porosity, as well as compressive strength and electrical resistivity. This study concludes that an ideal content of 10% POFA with a foaming agent-to-water ratio (fa/w) of 1/60 can achieve the best strength of foamed concrete. Furthermore, a partial cement replacement with 20% POFA could potentially increase the compressive strength to levels similar to those of normal foamed concrete (without POFA). [ABSTRACT FROM AUTHOR]

This study investigates the mechanical properties of polypropylene fiber-reinforced foamed concrete (PPFRFC) under high strain rates and large compressive deformation, focusing on the effects of varying fiber contents and lengths. Results show both peak and plateau stress increase with fiber content, reaching a maximum at 1.5 wt.% before decreasing. Similarly, increased fiber length enhances both stresses, but beyond 9 and 14 mm, they decline. The dynamic increase factor is sensitive to fiber content and length, with the lowest values observed at 1.5 wt.% content and 9 mm or 14 mm length. Failure mode analysis shows that as fiber content increases, damage extent decreases, with fewer fragments. At 1.5 and 2.0 wt.%, specimens largely retain their overall contour after impact, while fiber length has a smaller effect on failure mode. [ABSTRACT FROM AUTHOR]

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This study has been adopted to examine the effect of carbon fibre‐reinforced polymer (CFRP) sheet strengthening methods on the flexural behaviour of modified foamed concrete beams reinforced with different steel reinforcement ratios, and it deals with the enhancement in flexural behaviour of conventional nonstrengthened FC beams. Twelve modified foamed concrete beams were produced in three groups depending on the reinforcement ratio (under, balanced and over) and strengthened with externally bonded CFRP sheets applied in different methods (bottom layer, U jacket and hybrid). The examined flexural variables in four‐point bending were ultimate load, fracture mode, crack width, ductility, stiffness and deflection. The results showed an increase in the carrying capacity of foamed concrete beams strengthened with CFRP sheets by (2.5%–109%) compared to the reference nonstrengthened foamed concrete beams. The stiffness of the concrete samples reinforced with CFRP sheets were improved by 13%–306% compared to nonstrengthened foamed reference beams. For a given reinforcement ratio, it was found that the best CFRP sheets strengthening method was by applying the CFRP sheets in hybrid (wrap 0° + 90°). [ABSTRACT FROM AUTHOR]

AbstractThis study investigates the bleeding and water permeability characteristics in Foamed Concrete (FC) containing natural zeolite as cement substitute and Cuttle-Bone Powder (CBP) as nano-bio-filler. The aim of this study is to conduct a comparative analysis on pore structure modifications and engineering properties between conventional FC and admixture modified FC. First; four distinct FC mixes were obtained by adding CBP as an additive at 0%, 10%, 20% and 30%. Second; three mixes were produced; by replacing cement with calcinated natural zeolite at 5%, 10% and 15% of the mix containing 5%, 10% and 15% CBP; respectively. The foam volume was varied at 10%, 20%, 30% and 40% by volume of concrete in each mix. The test results indicate that substituting cement with natural zeolite in FC containing CBP affects the microstructural properties. In addition, isolated air void formation and reduced foam breakage was observed which restricts the bleeding, drying shrinkage and permeability. [ABSTRACT FROM AUTHOR]

The structural behavior of Nine Fibrous Ferro-Foam cement (FFFC) panels with (400×600×40) mm has been investigated in this study. Ferro-Foam cement is an alternative light weight composite material combine two technologies: ferrocement and foam concrete, to exploit the beneficial advantages of both technologies in line with sustainability. The mechanical properties of foamed concrete were optimized by increasing density and steel fiber addition. The first group includes four panels with different densities made of plain foamed concrete with silica fume and superplastizer without fibers to evaluate density effect. Mixes with 1800 Kg/m3 were selected to analyze steel fiber role on panels structural behavior (fiber content 0.5% and 0.6%) in the second group. Three FFFC panels in third group with density 1800 Kg/m3 and 0.6% steel fiber (optimum) reinforced with (2, 4 and 6) layers of steel wire mesh to study the effect of reinforcement. The results indicated that increasing the density of foamed concrete improves compressive and flexural strength. The addition of steel fibers significantly increases load capacity and ductility, while increasing number of steel wire mesh layers further improves structural performance and crack control. These findings suggest that FFFC panels are a promising sustainable alternative for a variety of construction applications. [ABSTRACT FROM AUTHOR]

Cement manufacturing accounts for approximately 7% of anthropogenic CO2 emissions. To mitigate environmental impact and achieve "net zero" by 2050, developing cementitious materials that minimize cement consumption is crucial. This research aims to reduce cement usage in Foamed Concrete (FC). The study investigates the mechanical, durability, and thermal properties of FC using two distinct Supplementary Cementitious Admixtures (SCA): Glass Powder (GP) and natural zeolite. Cement was replaced with SCA at varying percentages (0%, 5%, 10%, 15%, 20%, and 25% by weight) in FC. The FC density was adjusted by incorporating foam at 15% and 30% of the total volume of concrete. The study evaluated the flowability of each mix in its fresh state. The mechanical properties were assessed by measuring compressive strength and ultrasonic pulse velocity. The performance of FC was further analyzed in terms of thermal conductivity, sorptivity, and water absorption. The test results revealed that FC with GP combinations exhibited high flowability and an improved strength-to-density ratio. Additionally, water absorption, sorptivity, and thermal conductivity were significantly reduced compared to conventional FC. An extensive cost-benefit analysis highlighted the feasibility of utilizing common waste materials to produce high-grade FC and assessed the impacts of cementitious admixtures as viable alternatives to cement. [ABSTRACT FROM AUTHOR]

Hot weather is one of the main problems the residential building construction field faces, especially in the southern hemisphere. Therefore, there is an increasing need to produce materials capable of reducing the high temperature impact. These materials should be characterized by thermal insulation properties without, though, their mechanical properties and load resistance being affected. In this research, cuboid and hexagonal hollow concrete blocks were produced from lightweight foam concrete with different hole shapes and a hole ratio of 30%. An analytical study was conducted for 8 models using the ANSYS v16 program, while the compression behavior and thermal performance of the selected models were studied. Ordinary Portland Cement (OPC), water, sand, and foaming agents were deployed in the production of foamed concrete. In addition to the use of admixtures, materials, such as Superplasticizer (SP), Class F Fly Ash (FA), and Silica Fume (SF), were also utilized. Moreover, the effect of the hole’s shape and the method of bonding were studied. The compressive strength of the concrete blocks, bond shear strength, thermal conductivity, and thermal resistance were tested. It was found that the cuboid shape of the hole block H7 was the most acceptable compared to the other shapes, with a compressive strength of 3.75 MPa, thermal conductivity of 0.149 W/m.k, and a bond shear strength of 0.157 MPa. At the same time, it was found that using bonding adhesive material gave the best results, with the cuboid blocks being compared to using mortar and mechanical bonding. [ABSTRACT FROM AUTHOR]

The bond-slip behavior between cold-formed thin-walled steel (CTS) and foamed concrete (FC) is a critical issue in the mechanical performance of FC-filled CTS composite wall structures. Thus, this study provides experimental and theoretical research on the bond-slip behavior between CTS and FC. A total of eleven specimens were tested using push-out configurations, considering the number of web holes, foamed concrete (FC) strength, anchorage length, and CTS section splice form. A constitutive model for bond-slip was proposed, and the regression formulas for accurately predicting the characteristic bond strength between CTS and foamed concrete were established. A finite element model was developed to investigate the bond-slip mechanism at the interface between CTS and FC. The bond-slip constitutive model accurately fits the experimental and finite element results. The results indicate that the ultimate bond strength of the specimens increases with the number of web holes; when the number of web holes reaches two, the ultimate bond strength is 155.4% of that of the non-perforated specimens. As the concrete strength increases from 3.43 MPa to 11.26 MPa, the ultimate bond strength of specimens with two web holes improves by 23.1%, while non-perforated specimens have a 54.7% enhancement. When the anchorage length is extended from 200 mm to 400 mm, the ultimate bond strength decreases by 29.3%. Additionally, when steel sections are joined in a double-span I form, the bond strength increases by 91.6% and 95.8% compared to the single-span form and the double-span box form, respectively. [ABSTRACT FROM AUTHOR]

This research aims to identify the optimal noise concrete barrier mix through two critical stages. The initial step involves calibrating a traffic noise model via a field survey at 18 locations, encompassing volume counts and noise levels at varying distances. The subsequent step entails laboratory tests on different concrete barrier materials. The researchers developed two regression models. In the laboratory, they investigated five barrier types: reinforced, three variations of foamed concrete, and foamed concrete without aggregate. Employing a 92 dB noise source, they measured noise levels at distinct distances from the barrier. Ultimately, foamed concrete without aggregate emerged as the most effective barrier, potentially reducing noise levels by up to 46.4% at a distance of 3 meters with the use of this barrier. [ABSTRACT FROM AUTHOR]

Reducing the weight of buildings—particularly dead loads—is one effective way to lower construction costs. Foam concrete offers a viable alternative to conventional concrete for non-structural elements. This paper reviews the impact of incorporating polypropylene, natural fibers, steel fibers from waste tyres, and carbon fibers on the tensile strength of foamed concrete. According to the literature, the polypropylene content varied between 0.2% and 0.8%, with different target densities. Steel fibers extracted from scrap tyres ranged from 0.2% to 0.6%, while carbon fiber and Henequen fiber (natural fiber) were used separately or in combination with polymers in volumetric fractions ranging from 0.5% to 1.5%. The results presented in this paper indicate that tensile strength gradually increased as the volume of fibers increased up to a certain point, suggesting an optimal dosage for enhancing performance.

Researchers are increasingly becoming fascinated by the possibilities of utilizing natural fibre, which is a byproduct of production processes, as an addition in concrete. This fibre exhibits a low density and is amenable to chemical changes. The primary aim of this research study is to examine the influence of agave cantula roxb. fibre (ACRF) in low-density foamed concrete (FC) after being subjected to different doses of alkali treatment using sodium hydroxide (NaOH). Various weight fractions of treated ACRF were employed in the FC mix, namely 0% (as the control), 1%, 2%, 3%, 4%, and 5%. FC with a density of 1060 kg/m3 was produced and subsequently tested. The three types of strength properties that have been evaluated and analysed included flexural, tensile, and compressive strengths. The findings from this study have revealed that the inclusion of 3% of treated ACRF in FC yields highly favourable results in relation to strength properties. The use of treated ACRF improves the FC’s strength characteristics, particularly its bending and tensile strength, by bridging microscopic cracks and filling up gaps. It is noteworthy to emphasize that accumulation and unequal dispersion of ACRF are possible if the weight fraction of ACRF applied above the optimal value of 3% which led to decrease in FC’s strength properties. This exploratory work will lead to a better understanding of the potential applications of treated ACRF in FC. It is critical to encourage the long-term development and implementation of FC products and technology.

The consumption of foamed concrete (FC) in conjunction with the incorporation of natural fibre is recognized as an outstanding effort in promoting sustainable practices. This effort is aimed at reducing greenhouse gas emissions and the impact it leaves behind on the environment. The goal of this experiment is to discover the viability of incorporating raw bamboo fibre (BF) into the fabrication of 1000 kg/m3density FC. The shrinkage, flexural, compressive, and tensile strengths of the material were the four characteristics that were considered throughout the analysis. The weight fractions of BF that were utilized were 0.0%, 0.1%, 0.2%, 0.3%, and 0.4% respectively. According to the results, the FC-BF composites’ drying shrinkage, compressive, flexural, and tensile strengths were best achieved when 0.3% BF was present. This was caused by the BF’s adhesion to the cementitious matrix of the FC. Additionally, BF functioned as an anti-micro crack that prevented FC from developing internally induced microcracks and cracks.

To investigate the damage characteristics of basalt fiber foamed concrete in freeze-thaw environment, four kinds of foam concrete with fiber volume fractions of 0, 0. 15%, 0. 30% and 0. 45% were subjected to freeze-thaw cycle tests for 0, 20, 40, 60 and 80 times, respectively. The damage evolution law, fracture types and crack development characteristics of foamed concrete were studied by the uniaxial compression-acoustic emission combined device. The results show that there are obvious stages in the compression process of foam concrete. Freeze-thaw cycles deteriorate the mechanical properties of foamed concrete. After 80 freeze-thaw cycles, the peak compressive strengths of four specimens with the fiber volume fractions of 0, 0. 15%,0. 30% and 0. 45% decrease by 65. 0%, 54. 4%, 24. 4% and 36. 1 %, respectively. Freeze-thaw cycle can reduce the activity of acoustic emission, promote the transformation of tensile cracks to shear cracks in foam concrete, and accelerate the expansion of internal pores and cracks in concrete. The addition of basalt fiber can reduce the internal damage of foamed concrete, promote the generation of tensile cracks, effectively inhibit the development of large-scale cracks, and improve mechanical properties. [ABSTRACT FROM AUTHOR]

In this paper, we study the influence of density and the water–cement (W/C) ratio on the slurry fluidity, compressive strength, and water absorption of foamed concrete (FC) and its mechanism of action, with the aim of proposing an optimal mix ratio for FC to reduce cement usage and carbon emissions in the construction industry and ensure the good overall performance of FC. In this experiment, two groups of experiments were designed using the control variable method. Fluidity and uniaxial compression tests showed that when the density was 600 kg/m3 and the W/C ratio was 0.6, the FC slurry had maximum fluidity, but its mechanical properties were poor and it collapsed easily. Conversely, by analyzing the uniaxial compressive strength/cement (UCS/C) ratio, it was observed that the mix ratio had a maximum cement utilization rate (W/C ratio) of 0.5 and a density of 1000 kg/m3. Nondestructive testing methods were used to measure the ultrasonic pulse velocity (UPV) and rebound value of the FC test block, and the strength and durability of FC were analyzed. The water absorption rate of the FC test block was tested, and the final analysis showed that the optimal mix ratio of FC in this test was W/C = 0.5, with a density of 1000 kg/m3. [ABSTRACT FROM AUTHOR]

Foamed concrete is increasingly utilized in protection engineering because it offers a high energy absorption ratio and a relatively low construction cost. To investigate the dynamic properties of foamed concrete, a series of dynamic compression tests are carried out on high-density foamed concrete with densities of 800 kg/m3, 1000 kg/m3, and 1100 kg/m3 under a strain rate range of 59.05 s−1~302.17 s−1 by using a Φ-100 mm split Hopkinson pressure bar (SHPB) device. The effects of strain rate on the stress–strain relationship, dynamic compressive strength, and dynamic increase factor of foamed concrete are discussed in detail. The results show that the dynamic mechanical characteristics of foamed concrete with different densities exhibit a significant strain rate enhancement effect. Additionally, the energy absorption characteristics of foamed concrete are investigated, demonstrating that it can effectively prevent the transmission of incident energy and that its energy absorption efficiency declines as the strain rate increases. A high-speed camera was also employed to capture the failure process of foamed concrete. The results exhibit that fracture production and development induce the failure of foamed concrete, the failure process of foamed concrete advances as the strain rate increases, and the failure mode becomes increasingly severe. [ABSTRACT FROM AUTHOR]

The global demand for energy has experienced a significant rise. The thermal performance of conventional concrete has been extensively studied, but there is still a significant amount of research needed to understand the effects of synthetic fibres on the thermal properties of lightweight foamed concrete (LFC). LFC popularity in the construction industry has increased rapidly due to the many benefits it offers over conventional concrete. Therefore, the goal of this study is to investigate the feasibility of incorporating polypropylene fibrillated fibre (PFF) into LFC to improve its thermal properties. The PFF was integrated into the LFC in diverse weight fractions, between 1% to 4%. Density of 1080 kg/m³ was made and evaluated. Spreadability, permeable porosity, conductivity, diffusivity and specific heat capacity were determined. The findings demonstrate that spreadability of fresh mix decreased when the weight fractions of PFF were increased from 0% (250 mm) to 4% (239 mm). The incorporation of 3% PFF to LFC greatly improves its conductivity and diffusivity. Specifically, the thermal conductivity decreases from 0.3307 W/mK (in the control) to 0.2643 W/mK, and the diffusivity decreases from 0.4426 m²/s (in the control) to 0.3843 m²/s. Compared to the control specimen, LFC's porosity increased slightly from 43.6% to 44.9% when 3% PFF was added. The findings revealed that the PFF possesses significant underlying potential for utilisation in cementitious materials, potentially serving a pivotal function in either reducing the thermal-inducing property or improving the heat transfer of the concrete. The utilisation of LFC-PFF composites may also result in significant energy savings. [ABSTRACT FROM AUTHOR]

Foamed concrete is increasingly utilized in engineering due to its light weight, excellent thermal insulation, fire resistance, etc. However, its low strength has always been the most crucial factor limiting its large-scale application. This study introduced an innovative method to enhance the strength of foamed concrete by using nano-Al2O3 (NA) as a foam stabilizer. NA was introduced into a foaming agent containing sodium dodecyl sulfate (SDS) and hydroxypropyl methylcellulose (HPMC) to prepare a highly stable foam. This approach significantly improved the foam stability and the strength of foamed concrete. Its drainage volume, settlement distance, microstructure, and stabilizing action were investigated, along with the strength, microstructure, and hydration products of foamed concrete. The presence of NA effectively reduced the drainage volume and settlement distance of the foam. NA is distributed at the gas–liquid interface and within the liquid film to play a hindering role, increasing the thickness of the liquid film, delaying the liquid discharge rate from the liquid film, and hindering bubble aggregation, thereby enhancing foam stability. Additionally, due to the stabilizing effect of NA on the foam, the precast foam forms a fine and uniform pore structure in the hardened foamed concrete. At 28 d, the compressive strength of FC0 (0% NAs in foam) is 2.18 MPa, while that of FC3 (0.18% NAs in foam) is 3.90 MPa, increased by 79%. The reason for this is that NA promotes the formation of AFt, and its secondary hydration leads to the continuous consumption of Ca(OH)2, resulting in a more complete hydration reaction. This study presents a novel method for significantly improving the performance of foamed concrete by incorporating NA. [ABSTRACT FROM AUTHOR]

The development of concrete with excellent water and frost resistance providing high level of sound and thermal insulation has triggered the formulation of foamed concrete. However, multiple laboratory studies are required to produce reasonable data to design the relevant codes and mathematics with which design of mixes is made easier at low cost. In this research paper, the artificial intelligence (AI)-based symbolic regression technique estimation of the compressive strength of foamed concrete has been reported. Foamed concrete has been a subject of serious research in sustainable built-environment due to its lightweight and structural functionality. In this research work, data gathering method was applied to gather a globally representative data base comprising concrete density to water density (concrete density g/cm3) (y/yw), water-cement ratio (W/C), and sand-cement ratio (S/C) as input variable and the compressive strength (Fc) as the study output. The dimensionless factors have been derived to eliminate data handling complexities and improve model performances. The 230 data entries from foamed concrete mixes were partitioned into 75% and 25% for training and validation data, respectively. At the end of the model execution, it was found that the response surface methodology (RSM) produced a symbolic closed-form equation like the genetic programming (GP), evolutionary polynomial regression (EPR), and the group method of data-handling-neural network (GMDH-NN). Even though the RSM closed with a minimum error, the GP, EPR and GMDH-NN were faster in runtime. The overall outcomes show that the GP outclassed the EPR, RSM and the GMDH-NN, though with minor margin. Meanwhile the EPR produced the highest outliers from the ±25% test of accuracy envelope. Overall, the present models outperformed those reported in the literature due the parameter reduction through dimensionless factors derivation and provided a decisive model to predict the Fc of foamed concrete. [ABSTRACT FROM AUTHOR]

This study validates the attributes of the mineral carbonation process employing circulating fluidized bed combustion (CFBC) ash, which is generated from thermal power plants, as a medium for carbon storage. Furthermore, an examination was conducted on the properties of construction materials produced through the recycling of carbonated circulating fluidized bed combustion (CFBC) ash. The carbonation characteristics of circulating fluidized bed combustion (CFBC) ash were investigated by analyzing the impact of CO2 flow rate and solid content. Experiments were conducted to investigate the use of it as a concrete admixture by replacing cement at varying percentages ranging from 0% to 20% by weight. The stability and setting time were subsequently measured. To produce foam concrete, specimens were fabricated by substituting 0 to 30 wt% of the cement. Characteristics of the unhardened slurry, such as density, flow, and settlement depth, were measured, while characteristics after hardening, including density, compressive strength, and thermal conductivity, were also assessed. The findings of our research study validated that the carbonation rate of CFBC ash in the slurry exhibited distinct characteristics compared to the reaction in the solid–gas system. Manufactured carbonated circulating fluidized bed combustion (CFBC) ash, when used as a recycled concrete mixture, improved the initial strength of cement mortar by 5 to 12% based on the 7-day strength. In addition, it replaced 25 wt% of cement in the production of foam concrete, showing a density of 0.58 g/cm3, and the 28-day strength was 2.1 MPa, meeting the density standard of 0.6 grade foam concrete. [ABSTRACT FROM AUTHOR]

Alkali-activated slag cementitious (AASC) foamed concrete (FC) has presented challenges such as rapid setting time and poor working performance. The use of sodium citrate (Na3Cit) as a retarding agent can improve the workability and microstructure of AASC foamed concrete. The effects of the dosage, modulus of water glass (WG, the main component is Na2O·nSiO2), and retarding agent on the properties and structure of FC were studied in this paper. The results indicated that using a water binder ratio of 0.4, WG with a modulus of 1.2, and an additional amount of 15% and 0.5% of Na3Cit, the prepared FC had a flowability of 190 mm. Its initial and final setting times were 3.7 h and 35.3 h. Its 7 d and 28 d compressive strengths reached 1.1 MPa and 1.5 MPa, respectively. After hardening, the pore walls were dense and consistent in size, with few larger pores and nearly spherical shapes. The addition of Na3Cit resulted in the formation of calcium citrate, which adsorbed onto the slag surface. This hindered the initial dissolution of the slag, reduced the number of hydration products produced, and decreased the early strength. With increasing curing time, the slag in the FC mixture dissolved further. This led to the decomposition of a portion of calcium citrate and the release of Ca2+. The Ca2+ reacted with [Si(OH)4]4− and [Al(OH)4]−, creating more C-(A)-S-H gel. This gel filled the voids in the FC and repaired any defects on the pore walls. Ultimately, this process increased the compressive strength of the FC in the later stages. [ABSTRACT FROM AUTHOR]

ABSTRACT Foamed concrete, a lightweight, cement slurry‐based cellular material, presents a promising solution to economic and environmental challenges in the construction industry. Its versatility spans from structural applications to thermal insulation and soundproofing, offering benefits such as low density, energy efficiency, and affordability. The study explored the feasibility of using locally sourced materials, specifically by utilizing three different powder detergents (K, M, and S) as foaming agents. These detergents were evaluated for their composition, density, and stability and then combined with two cement grades 32.5R and 42.5R. A total of 12 sample foamed concrete groups were manufactured and checked for compressive strength, density, and water absorption. The results demonstrated that all detergents in specific formulations successfully produced foamed concrete that met or exceeded the ASTM requirements of 1.4 MPa. Samples from Detergent K achieved a dry density range of 1.32–1.539 g/cm3 with 28‐day compressive strength ranges of 0.64–14.25 MPa. Samples from Detergent M produced dry densities in the range of 1.255–1.559 g/cm3 with a compressive strength range of 0.41–12.26 MPa and those from Detergent S produced dry density range of 1.061–1.394 g/cm3 with compressive strength range of 1.03–7. 75 MPa. Notably, there were correlations between the detergent's pH, the relevant oxide quantities and the foam's density and stability which together influenced the overall performance of the foamed concrete.

In recent years, mortar bricks or autoclaved aerated concrete (AAC), also known as foamed concrete, have been widely used as masonry wall materials. Foamed concrete, like bricks, can be produced by adding a foaming agent to achieve the desired weight and density, while meeting requirements for strength and durability. However, the search for sustainable construction materials has become imperative , including the use of waste materials to partially replace cement. The incorporation of SCM in the production of cement-based materials, such as foamed concrete, has a significant impact on reducing CO 2 emissions and promoting a sustainable environment. POFA, a secondary product derived from the palm oil industry that is typically left on the ground , poses environmental problems. Due to its good performance and pozzolanic reactions, POFA-based construction materials have great potential as alternatives to ordinary Portland cement. Unlike previous studies, this research evaluates the strength and durability of foamed concrete with variations in foam agent dosages, including finer particles of POFA (100μm) as a partial cement replacement. The study produced a total of 6 batches of foamed concrete, measuring compressive strength, porosity, water absorption, and electrical resistivity. Additionally, the research examined the correlation between compressive strength and porosity, as well as compressive strength and electrical resistivity. This study concludes that an ideal content of 10% POFA with a foaming agent-to-water ratio (fa/w) of 1/60 can achieve the best strength of foamed concrete. Furthermore, a partial cement replacement with 20% POFA could potentially increase the compressive strength to levels similar to those of normal foamed concrete (without POFA).

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.