The rising environmental burden of Portland cement production has intensified the demand for eco-friendly binders that support sustainable construction. This study investigates the development and performance of eco-friendly self-compacting geopolymer concrete (SCGC) produced from industrial by-products, including fly ash (FA), ground granulated blast furnace slag (GGBFS), silica fume (SF), metakaolin (MK), and glass waste powder (GWP). Twenty-one binder formulations were evaluated for fresh-state workability, mechanical performance, durability, and microstructural characteristics under different curing regimes. Fresh properties were assessed using slump flow, V-funnel, L-box, and J-ring tests, while hardened-state evaluations included compressive and flexural strength, Young’s modulus, and water absorption. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed on selected mixes to examine microstructural features and crystalline phase development. Results highlight a strong dependency of SCGC performance on binder composition and curing conditions. Mixes rich in GGBFS and SF demonstrated superior mechanical and durability performance, achieving compressive strengths of up to 102.4 MPa under water curing and 107.6 MPa under heat curing, along with negligible water absorption, reflecting a dense and well-developed gel matrix. SEM micrographs confirmed homogeneous, compact microstructures in high-performing mixes, while XRD analysis revealed broad amorphous humps indicative of well-formed N-A-S-H and C-A-S-H gel phases with minimal crystalline residues. In contrast, FA-dominant mixes displayed delayed strength development, and MK-GWP-rich systems exhibited higher porosity and reduced strength. This study underscores the significance of precursor synergy, optimized curing strategies, and microstructural refinement in tailoring SCGC for high-performance, durable, and low-carbon applications in sustainable construction with values ranged from 38.64 GPa (Mix 21) to 25.04 GPa (Mix 19) at 28 days. Stiffer mixes corresponded to denser matrices containing GGBFS and silica fume, whereas lower values were linked to weaker bonding and higher porosity.

This study investigates the influence of palm oil fuel ash (POFA), in micro- and nanoparticle sizes, as a partial cement substitute in high-strength concrete (HSC). Thirteen mixtures incorporating varying proportions of micro-POFA (10%-30%) and nano-POFA (2%-8%) were assessed for workability, mechanical properties, durability, and microstructural characteristics. The optimal formulation-10% micro-POFA combined with 4% nano-POFA-yielded a peak compressive strength of 100.7 MPa at 91 days, alongside enhanced tensile, flexural, and elastic properties, with markedly reduced water permeability. Thermal resistance evaluations confirmed adequate strength retention up to 800 degrees C. Scanning electron microscopy identified a denser matrix and refined interfacial transition zone, attributed to heightened pozzolanic reactivity. Ensemble machine learning models accurately predicted compressive strength outcomes, complemented by a graphical user interface enabling real-time strength estimation for practical engineering applications. These findings affirm the viability of optimized micro-nano POFA blends in sustainable, high-performance concrete development.

This study presents a comprehensive experimental and numerical investigation into the flexural behavior of sustainable self-compacting geopolymer concrete (SCGC) beams incorporating granite waste and slag powder. While the environmental benefits of geopolymer concrete are widely studied, its structural performance, particularly when utilizing industrial wastes, remains underexplored. To address this gap, six reinforced concrete beams (100 × 150 × 1500 mm), including five SCGC beams and one Portland cement concrete (PCC) control beam, were tested under four-point bending. The investigation systematically evaluated the influence of key parameters: the longitudinal reinforcement ratio (0.85

This research investigates the shear performance of sustainable self-compacting reinforced geopolymer concrete (GPC) beams incorporating granite waste powder (GWP) and ground granulated blast-furnace slag (GGBFS) as eco-friendly binding agents through experimental and numerical analyses. Five geopolymer reinforced concrete beam specimens (100 mm × 150 mm × 1500 mm) were tested under two-point loading conditions to evaluate the influence of longitudinal reinforcement ratio (0.85% to 2.0%) and shear span-to-effective depth ratio on the structural shear performance. The experimental investigation revealed that geopolymer reinforced concrete beams exhibit shear behavior characteristics similar to conventional Portland cement concrete beams, with the 2.0% reinforcement ratio achieving 18.3% higher shear strength compared to the 0.85% reinforcement ratio, while shear capacity increased proportionally with increasing shear span-to-depth ratio. Experimental data, including load–displacement response, shear strength measurements, strain distributions, failure modes, and crack patterns, were studied. Finite element nonlinear analysis was conducted by modifying the concrete modulus and stress–strain relationships to reflect the properties of geopolymer concrete using ABAQUS software integrated with the concrete damaged plasticity model. The results demonstrated that for the tested geopolymer reinforced concrete beams, first cracking load, steel yielding load, and ultimate load capacity increased systematically with increasing tension steel reinforcement ratio and proportionally with higher shear span-to-depth ratios.

One of the primary challenges with ultra-high-performance concrete (UHPC) is its high cement content, typically around 1000 kg/m3, which raises significant environmental concerns. Therefore, reducing cement content while maximizing its efficiency is essential for improving both the sustainability and performance of UHPC. This study focuses on developing an environmentally friendly UHPC mix with a reduced cement content of 700 kg/m3, reinforced with hybrid fibers: steel fiber (StF) and polypropylene fiber (PPF). The main objective of this research is to evaluate the effects of these two fiber types on the mechanical properties and durability of UHPC. It also aims to achieve a balance between enhanced strength, crack resistance, and load-bearing capacity under various conditions. Fiber volume percentages ranging from 0%, 0.25%, 0.5%, 0.75%, and 3% were incorporated for both StF and PPF, used as single or hybrid fibers. The study assessed several key mechanical and durability properties, including compressive strength, tensile strength, flexural strength, modulus of elasticity, porosity, water absorption, sorptivity, fire resistance, impact resistance, and energy absorption. Additionally, the microstructural properties were analyzed using scanning electron microscopy (SEM). In addition, the life cycle assessment (LCA) of UHPC was evaluated in terms of cost-effectiveness, energy efficiency, and carbon efficiency. Among the tested UHPC blends, despite the relatively low cement content, the mix containing 0.75% StF and 0.25% PPF demonstrated superior performance, achieving a compressive strength of 155 MPa, tensile strength of 5 MPa, and flexural strength of 4 MPa, which outperformed the mix containing 3% mono-StF. Furthermore, this hybrid fiber combination exhibited up to a 47% increase in initial and final kinetic energy absorption compared to its mono-StF counterpart. The hybrid blend of 0.75% StF and 0.25% PPF also showed reduced porosity (1.73%), lower water absorption (0.602%), and decreased saturation absorption (16.6%) compared to the monofilament StF mix. SEM analysis further confirmed that the hybrid fiber composition improved the fiber-matrix interface and reduced porosity. Furthermore, among all the mixes, the control and 3P mixes showed the highest environmental efficiency and reduced carbon emissions, energy consumption and costs. These results indicate that hybrid fiber systems can significantly enhance the mechanical performance, impact resistance, and durability of UHPC while simultaneously promoting the use of environmentally friendly cementitious compositions. This highlights the potential of hybrid fiber-reinforced UHPC for advanced structural applications.

Human activities and recurring natural disasters generate large quantities of construction waste while simultaneously increasing the demand for low-cost and emergency shelters. This study investigates the mechanical and hygrothermal performance of rammed earth incorporating construction and demolition waste compared to conventional red brick construction under hot climatic conditions. Two full-scale experimental building units (3.1 m × 3.1 m × 2.9 m) were constructed and monitored under two test scenarios: a baseline condition without surface treatment (Test 1) and a modified condition using a reflective lime-based coating (Test 2). Results show that the rammed earth unit achieved significantly improved thermal stability, with indoor temperature reductions of 4–13 °C and time lag up to 420 min, compared to 2–11 °C and shorter delays in the red brick unit. Relative humidity fluctuations were also significantly damped due to the hygroscopic nature of rammed earth. The findings confirm that thermal mass is the dominant factor governing indoor environmental stability, while surface reflectivity provides secondary improvement. The study provides full-scale experimental evidence supporting the use of construction waste-based earthen materials for sustainable shelter applications in hot climates.

Abstract This study experimentally and numerically investigated the shear behavior of UHPFRC deep beams with internal-opening reinforcement, focusing on how internal-opening reinforcement detailing can mitigate opening-induced shear capacity loss. The test program included eight simply supported UHPFRC deep beams tested under four-point loading and arranged into two groups with different geometries. Group I comprised five beams with an a/d ratio of 0.61, including one solid reference beam and four beams with a square opening within the shear span, and intersected the load path. Group II comprised three beams with an a/d ratio of 0.79 and different opening sizes. Three internal opening reinforcement techniques with different ratios were examined: (1) additional vertical and horizontal bars around the opening ( µ av = µ ah = 2.7% or 2.4%), (2) additional stirrups ( ρ va = 4.2% or 5.6%) with vertical and horizontal bars around the opening ( µ av = µ ah = 2.7% or 2.4%), and (3) diagonal cross-bars around the opening ( µ ax = 1.8%). The results showed that the unreinforced opening reduced the cracking load by 41.4% and the ultimate load by 40.4%, compared with the solid beam. Techniques (1), (2), and (3) increased ultimate shear capacity by 16.5%, 69.2%, and 25.3%, respectively, versus the unreinforced opening beam, achieving approximately 54.6%, 79.4%, and 58.8% recovery of the solid-beam capacity. A 3D numerical model using concrete damage plasticity reproduced damage and load–deflection responses, with mean experimental-to-numerical ratios of 1.08 for ultimate shear load and 1.30 for midspan deflection, supporting the model’s predictive reliability for deep beams with internal opening reinforcement.

Abstract This study explores the possibility of producing sustainable structural lightweight concrete (LWC) based on limestone calcined clay cement (LC³) using waste from construction and demolition. The main innovation is the dual substitution of waste-derived materials for traditional LC³ constituents: crushed brick powder (CBP) was used in place of metakaolin (MK), and recycled concrete powder (RCP) was used in place of limestone powder (LSP). To achieve lower densities, nine concrete mixtures were created using crushed brick as both fine and coarse aggregates in addition to an air-entraining agent. Flowability, dry density, ultrasonic pulse velocity, compressive strength, resistance to magnesium sulfate attack and high temperatures (200 and 400 degrees Celsius), water absorption, and porosity were all assessed through an extensive experimental program. With only a small drop in 28-day compressive strength (5–8%) and a slight increase in water absorption (10–12%), the results showed that CBP is a very promising substitute for MK. All mixtures met the structural LWC requirements of DIN EN 1045-1 (dry density of 1650–1850 kg/m³ and strength > 24 MPa), but substituting RCP for LSP resulted in a more noticeable decrease in 28-day compressive strength (15–20%) and an increase in water absorption (13–18%). Additionally, after 180 days of sulfate exposure, all LC³ systems showed very little mass loss (< 0.7%) and maintained over 80% of their residual strength at 400 °C. According to the study, CBP and RCP can effectively and sustainably replace MK and LSP in LC³-based LWC, allowing for a 60% reduction in clinker while preserving structural integrity and promoting waste valorization.

The structural performance of reinforced concrete (RC) columns can be substantially improved by using advanced confinement systems and sustainable cementitious materials. This study presents an integrated experimental, numerical, and analytical investigation of RC columns strengthened with self-compacting geopolymer concrete (SCGC) and carbon fiber-reinforced polymer (CFRP) under axial compression. Twelve column specimens were tested across four groups: conventional RC columns, unconfined SCGC columns, SCGC-jacketed columns (CONF. SCGC), and CFRP-wrapped columns (CONF. FRP), in three cross-sectional geometries: square (177 × 177 mm), rectangular (265 × 177 mm), and circular (Ø200 mm). Experimental results demonstrated that replacing conventional concrete with SCGC improved deformation capacity, increasing the ultimate axial displacement from 2.07 mm in the reference square RC column (RC C1) to 3.21 mm in the corresponding square SCGC specimen (SCGC C1). On a normalized stress basis, the unconfined SCGC specimens achieved ultimate axial stress values of 56–64 MPa compared to 41–49 MPa for the RC reference columns of the same geometry, representing material-level strength gains of 1.30–1.49×. The application of external confinement further enhanced column behaviour. The CFRP-wrapped specimens achieved the highest material-level strength efficiency, with normalized ultimate axial stress values of 98–108 MPa for the square and rectangular geometries, representing gains of 2.01–2.41× over the corresponding unconfined RC columns of identical cross-section. The SCGC-jacketed specimens achieved the highest absolute load capacities, with CONF. SCGC C2 reaching 8270 kN and a maximum stiffness of 5531 kN/mm and energy absorption of 19,740 kN·mm. However, on a normalized stress basis, the SCGC-jacketed square and rectangular specimens achieved 45–47 MPa, comparable to the RC reference columns, confirming that their absolute load gains are primarily attributable to section enlargement rather than intrinsic material strength enhancement. The circular SCGC-jacketed specimen achieved a normalized stress of 43 MPa, consistent with the same trend. A three-dimensional nonlinear finite element model developed in ABAQUS using the Concrete Damaged Plasticity model and cohesive zone interactions showed close agreement with experimental results, with mean prediction ratios of 1.03 for ultimate load and 0.96 for displacement. An analytical model provided conservative estimates of axial capacity. The findings demonstrate that CFRP wrapping offers superior material-level confinement efficiency, while SCGC jacketing provides the highest absolute load capacity through combined section enlargement and passive confinement, representing a potentially more environmentally friendly strengthening strategy for existing RC columns.

The construction industry must reduce its environmental footprint and use sustainable materials with low energy and carbon emissions. Conventional masonry and concrete are reliable, durable, and widely used construction materials, but they use up natural resources and produce a considerable amount of CO2 emissions. Rammed earth (RE) is a sustainable material and an environmentally friendly construction method that is less energy intensive and exhibits good thermal performance; however, its strength is a limitation for larger structural projects. To address these challenges, this study presents an experimental evaluation of the thermo-mechanical, environmental, and economic performance of stabilized rammed earth (RE) walls incorporating construction and demolition waste (CDW) and calcium oxide (CaO) as sustainable stabilizing additives. This research aims to enhance the structural integrity, thermal insulation, and sustainability of RE systems by partially replacing natural soil with CDW (10–30%) and CaO (2–6%). Seven mix designs were designed and tested for compaction properties, unconfined compressive strength (UCS), thermal conductivity, embodied energy, CO2 emissions, and thermal behavior under simulated hot climate conditions with varying relative humidity. The optimal mixture, CDW30–C2 (30% CDW and 2% CaO), achieved a peak UCS of 9.3 MPa at 28 days, the lowest thermal conductivity (0.88 W/m·K), moderate embodied energy (705.27 MJ/m3), and reduced carbon emissions (177.73 kg/m3), offering a high strength-to-impact efficiency. To validate its practical applicability, a full-scale RE wall was constructed using the CDW30–C2 mixture and subjected to thermal insulation tests in a controlled climate chamber at 40–80% relative humidity. The findings demonstrated a time lag of up to 90 min and a decrement factor of 0.85, indicating favorable thermal inertia and effective moderation of heat transfer. The synergistic effects of CDW particles enhanced mechanical interlocking and matrix densification, while CaO contributed to pozzolanic reactivity and void filling. Compared to conventional fired brick and concrete, the optimized RE mix demonstrated competitive performance with significantly lower environmental impact. These findings demonstrate the viability of CDW–CaO stabilized rammed earth as a climate-resilient, low-carbon, and resource-efficient building solution for sustainable construction.

The pressing demand for environmentally friendly construction materials has prompted extensive research into alternatives to conventional cement. This investigation focuses on using of Palm Oil Fuel Ash (POFA) in its micro and nano forms as a partial cement substitute in ultra-high-performance concrete (UHPC). A total of thirteen distinct concrete mixtures were created incorporating POFA, silica fume, quartz powder, superplasticizer, and steel fibers. The study evaluated the effects of these materials on key properties such as compressive strength, water permeability, and residual strength under elevated temperatures. Notably, the POFA-modified mixtures, specifically mix with 20

Developing longer-lifespan concrete with minimized surface cracking is crucial for sustainable construction. This study investigates self-healing rubberized concrete incorporating 15% recycled rubber waste as a sand replacement. To enhance strength and flexibility through crack closure, bacteria Sporosarcina Pasteurii and Rhizobium Leguminosarum were introduced at 20% of the water volume. Slump, compressive and flexural strength, SEM, and EDX were the tests performed to identify the effects of bacteria and rubber on the concrete characteristics. The results illustrated that the use of rubber as a partial replacement for sand significantly reduced concrete workability and mechanical performance, with slump, compressive strength, and flexural strength decreasing by up to 77%, 49%, and 47%, respectively. However, incorporating SpP and RL bacteria, particularly at concentrations of 1010 + 1010 and 1014 + 1010, effectively mitigated these negative effects. The improvement in compressive strength and flexural strength was up to 98.7% and 137.4%, respectively for mixture containing SpP and RL bacteria at concentration 1010 +1010 compared to mixture containing 15% rubber only. Complete crack self-healing was achieved in SHRC mixtures after 80 days. Microstructure analysis revealed that the formation of calcium carbonate in large quantities within the concrete matrix, which works to heal cracks and fill voids. Thus, using rubber with bacteria to heal cracks could be a cost-effective solution that helps to increase tire rubber recycling rates.

In the quest for sustainable construction solutions, This study investigates the utilization of magnetite powder (MP) and ilmenite powder (IP), sourced from Egyptian black sand, as novel and environmentally sustainable substitutes for cement in high-performance mortar. Seven mortar mixes were developed, integrating MP and IP at substitution rates of 10 %, 20 %, and 30 %, and their physical, mechanical, and microstructural characteristics were meticulously assessed. The pozzolanic activity of MP and IP was confirmed using strength activity index (SAI) and thermogravimetric analysis (TGA), establishing their viability as supplemental cementitious materials (SCMs). The testing results indicated substantial enhancements in mortar performance. A 10 % substitution of cement with IP led to a 20 % enhancement in compressive strength relative to the control mix. Furthermore, MP-enhanced mortar maintained 85 % of its strength after exposure to 600 degrees C, demonstrating exceptional fire resistance. Workability studies indicated that MP and IP enhanced flowability, resulting in flow widths increasing by as much as 15 %. Ultrasonic pulse velocity experiments corroborated improved microstructure density, especially at the 10 % replacement level. Advanced methodologies, including scanning electron microscopy (SEM) and X-ray diffraction (XRD), shown that MP and IP promote the synthesis of calcium silicate hydrate (C-S-H) gels, hence improving durability and diminishing porosity. These findings highlight the viability of MP and IP as sustainable alternatives to cement, providing superior mechanical qualities, fire resistance, and workability, while reducing the environmental footprint of construction materials. This study establishes a foundation for further research on the utilization of these materials in sustainable construction techniques.

Self-healing rubberized concrete (SHRC) represents an innovative approach to improving the durability, strength, and flexibility of concrete while addressing sustainability challenges. In this study, two bacterial strains, Rhizobium leguminosarum (RL) and Sporosarcina pasteurii (SP), were incorporated at 20% of the total water volume with three concentrations (108, 1010 and 1014 cells/mL), along with 15% recycled rubber as a partial sand replacement. The impact of these modifications on workability, mechanical performance, impact resistance, and crack healing was evaluated through slump tests, compressive and tensile strengths, impact resistance analysis, and microstructural studies using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The addition of rubber particles reduced workability and mechanical performance due to their porous nature and lower stiffness. However, incorporating bacterial cultures (RL + SP), particularly at concentrations of 1010 + 1010 cells/mL, significantly improved these properties. Indirect tensile strength increased by up to 99%, while compressive strength rose by 98.7% compared to rubber-only mixes. Impact resistance improved by 131.8% at the first crack and 123.1% at the ultimate crack under the same bacterial concentration. Enhanced microstructural characteristics, including reduced voids and extensive calcium carbonate precipitation, facilitated effective crack healing and improved durability. The combined effects of rubber and bacterial agents demonstrated superior self-healing capabilities, with complete crack closure observed within the rubberized concrete matrix. This study will describe previous related works on the mechanical behavior of rubberized concrete and compare the behavior of rubberized concrete containing rubber only to that containing two types of bacteria with rubber. These findings highlight the potential of SHRC to deliver sustainable, high-performance concrete with improved mechanical and durability characteristics through innovative self-healing and material recycling strategies. The findings suggest the possibility that bacterial therapy would be a more economical option than CFRP rehabilitation for cracked concrete members, which could be a suggestion for further study.

Engineered Cementitious Composites (ECC) are advanced materials known for their superior ductility, high durability, and crack resistance, making them ideal for a variety of structural applications. This research investigates experimentally the impact of hybrid steel fiber (SF) and macro polypropylene fiber (PPF) on the performance of ECC, studying the effects of varying the ratio of steel-to-macro polypropylene fibers while maintaining a constant fiber content of 2 % of the mixture volume, as well as exploring changes in the aspect ratio of the fibers. The study examines the effects on slump flow, compressive strength, tensile strength, flexural strength, ductility, toughness, sorptivity, and Scanning Electron Microscopy (SEM) analysis. Results indicated that increasing the macro PPF content enhanced workability. The mixture incorporating only macro PPF achieved a 61.8 % higher slump flow compared to the one containing solely SF. On the other hand, the mix containing only SF exhibited a yield stress nearly 12 times higher than that of the mix with only macro PPF. Hybrid combinations improved the balance between workability and strength, with a non-linear inverse relationship observed between slump flow and yield stress. At 28 days, the hybrid mix containing 1 % SF and 1 % macro PPF achieved a compressive strength of 48.1 MPa, which is 3.5 % higher than the mix with PPF alone. Similarly, tensile and flexural strengths improved by 37.4 % and 34.6 %, respectively. The presence of hybrid fibers does not significantly influence the behavior of ECC, as long as the fiber content remains at 2 % of the total volume of ECC during the pre-cracking stage of the flexural test. The aspect ratio of the fibers has a minimal effect on the toughness of ECC. Furthermore, mixtures containing a single type of fiber help reducing water absorption per unit area. SEM analysis revealed improved fiber-matrix bonding and reduced crack widths in hybrid mixes, especially with the combination of SF and macro PPF. This cost-effective blend provided high mechanical performance, along with excellent workability and durability. Unlike previous studies relying on costly and less available PVA or PE fibers, this study utilizes a cost-effective hybrid of macro PPF and steel fibers to achieve comparable or superior mechanical properties. Additionally, the use of natural sand instead of silica sand enhanced sustainability and practicality, making it a novel and economical solution for ECC.

The growing demand for sustainable ultra-high-performance concrete (S-UHPC) requires eco-efficient mix designs that reduce cement consumption and environmental impacts. In this study, a novel S-UHPC was developed using reprocessed waste glass powder (Re-WGP), micronized quartz powder (MQP), and crushed desert sand (CQDS), optimized through particle packing and response surface methodology. The cement content was reduced by 50 %, resulting in significant decreases in CO2 emissions, production cost, and embodied energy. The optimal 50 C/50Re-WGP mixture achieved the lowest void ratio (0.12), highest wet packing density (0.88), and superior durability with reduced water absorption and permeability. Microstructural analyses (XRD, TGA, and SEM) confirmed enhanced pozzolanic activity and a denser internal matrix, supporting the observed improvements in durability. Life cycle assessment further demonstrated substantial benefits, with global warming potential decreasing from 1040.70 to 676.2 kg/m(3) , cost from 274.65 to 214.96 $/m(3) , and embodied energy from 59.9 to 39.76 MJ/m(3) /MPa. Hybrid machine learning models achieved accurate predictions (R-2 > 0.90) for durability parameters, while SHAP-based sensitivity analysis revealed that the water-to-binder ratio, cement content, and aggregate proportion were the most influential factors controlling absorption and permeability. These findings highlight the potential of combining sustainable mix design with AI-based prediction to advance eco-friendly S-UHPC for construction applications.

This study assesses the performance of industrial solid wastes include crushed brick powder (CB), ceramic powder (CP), and basalt powder (BP) as alternatives to metakaolin (MK), and recycled concrete powder (RC) as alternative to limestone (LS) in LC3 manufacturing. Nine mixtures were investigated with substitution of 50 % of cement, 30 % of MK, CB, CP, or BP and 20 % of LS or RC. Various experimental tests were performed to ensure the efficiency of these wastes such as consistency, mechanical performance, durability, elevated temperatures exposure at 200 degrees C and 400 degrees C, and microstructure (SEM). The results indicated that CB is relatively an equal alternative to MK, attaining compressive strengths of 45.2-58 MPa at 28 days and exhibiting low sorptivity (0.28-0.46 kg/m2hr1/2). CP improves thermal resistance, maintaining 90 % of its strength after exposure to 400 degrees C, whereas BP with limited pozzolanic activity results in a 23.5-25.9 % reduction in strength after 28 days of curing. The substitution of LS with RC reduces sorptivity (0.16-0.48 kg/m2hr1/2) and decreases compressive strength by 16.2-26.4 %. Nevertheless, its use can save millions of tons of construction and demolition waste from landfills disposal. All mixtures showed significant sulfate resistance, with strength improvements after 90 days. The microstructure characterization demonstrated dense matrices in CB and MK-based mixtures compared to increased porosity in BP. This study assesses LC3 's compatibility with various industrial wastes, confirming CB and RC as viable substitutes for MK and LS, respectively. These findings enhance sustainability principles by converting waste into valuable materials for low-carbon cement manufacture, besides the environmental benefits of minimizing waste disposal problems.

Engineered cementitious composites (ECC) are known for their exceptional ductility and ability to tightly control crack widths. However, ECC's high consumption of sand raises concerns about the depletion of natural resources. To address this, the present study assessed the mechanical, durability, and microstructure properties of hybrid basalt fibre ECC incorporating non- pozzolanic industrial waste materials namely; crumb rubber (CR) and stone processing waste (SPW) as sand partial replacements at levels of 10 %, 20 %, and 30 % by volume. The study employed different types of SPW namely; basalt waste, dolomite waste, and marble waste. The effect of physical treatment of CR using SPW and an activator was also evaluated at 20 % replacement level of sand. Several measurements including slump, slump-flow, compressive strength, uniaxial tensile strength, flexural strength, and sorptivity were carried out. The influence of various curing methods on 28-day compressive strength and overall mechanical performance of ECC was also assessed. Results indicated that using untreated CR reduced compressive and tensile strengths by 28.1 % and 11.2 %, respectively, while this enhanced flexural strength by 25.1 % in comparison to the control ECC. Conversely, incorporating 20 % treated CR increased compressive strength by up to 15.2 % and tensile strength by up to 19.6 %, although flexural strength decreased by 16.5 %. Moreover, substituting 20 % of sand with SPW improved compressive strength by up to 8.5 % and tensile strength by up to 14.3 %. The results showed that utilizing SPW in ECC can potentially reduce environmental impacts, including costs, energy consumption, and carbon emissions, thereby improving ECC's sustainability while maintaining or enhancing its performance.