Highly porous, eco-friendly nano-silica is essential for sustainable applications. Biomass-derived nanosilica (n-SiO2) provides a sustainable route to enhance cement-based materials (CBMs); however, the role of its intrinsic properties, particularly specific surface area (SSA), remains inadequately understood. This study systematically and uniquely explores how engineered SSA in highly porous n-SiO2 interacts with varying water-to-binder systems to govern low-carbon cementitious performance. Using a Box–Behnken Design (BBD), the cement strength was optimized. The impact of these influencing factors on hydration kinetics, microstructural properties, and the mechanisms underlying the enhanced properties has been explained. The study revealed that lower and medium SSA n-SiO2 (263 and 579 m²/g) significantly enhanced cement strength at low w/b ratios, whereas high SSA performed better in high w/b systems. The 3

The improper disposal of municipal solid waste incineration fly ash (MSWI-FA) presents serious environmental and health risks due to its toxic constituents, highlighting the urgent need for sustainable treatment and reuse strategies. This study aims to evaluate the potential of non-traditional cementitious materials in the stabilization/solidification (S/S) of MSWI-FA, thereby offering a low-carbon alternative to conventional methods. The research involves a comprehensive review and analysis of the chemical and physical characteristics of MSWI-FA, with a particular focus on the leaching behavior of heavy metals and the effectiveness of various pretreatment techniques. The scope includes an in-depth investigation of magnesium-based cement, alkali-activated binders, and calcium-aluminate cement, assessing their performance in immobilizing hazardous components of MSWI-FA. Furthermore, the study examines the incorporation of treated MSWI-FA into concrete and assesses its impact on mechanical strength, durability, and microstructural properties. Results from the literature suggest that these alternative binders can effectively stabilize MSWI-FA, reduce environmental risks, while contributing to circular construction practices. The study concludes that non-traditional cementitious materials hold significant promise for integrating waste valorization into sustainable building practices. It recommends further experimental studies, long-term leaching assessments, and standardization of treatment protocols to support the safe and widespread adoption of MSWI-FA in construction materials.

In high-energy ball milling, nanoparticle formation is governed by collision energetics and impact frequency, which collectively control particle refinement, structural disorder, and surface reactivity. The synthesis is primarily influenced by milling speed, ball size distribution, milling duration, ball-to-powder ratio, and the intrinsic properties of the feed material. Despite their critical role, the combined effects of these milling parameters on the physicochemical properties of biomass-derived nanoparticles remain poorly understood, primarily due to insufficient experimental probes. Therefore, this study systematically examines the interactive effects of milling speed (400–800 rpm), powder-to-ball mass ratio (1:8, 1:10, and 1:12), and small-to-large ball mass fraction (20%, 60%, and 100%) on the properties of synthesized engineered nanoparticles from biomass waste. The functional performance of the resulting nanoparticles as cement nano-additives or partial clinker substitutes was further evaluated under different dispersant conditions. The study revealed that optimized milling conditions yield ultra-fine nanoparticles (5–20 nm) with partially amorphized SiO2 networks. Statistical analysis found that milling speed exerted the dominant influence on nanoparticle quality, followed by powder-to-ball ratio and ball size distribution (p < 0.05). When incorporated at low dosages (1–1.5 wt.%), the engineered nanoparticles enabled 10–15% clinker replacement while achieving early-age compressive strength gains of up to 30%. These results demonstrate that biomass-derived nanoparticles can deliver superior performance at substantially lower dosages. This offers a "more cement replacement for less material" pathway that supports clinker reduction, CO₂ mitigation, and the development of high-performance, sustainable cement systems.

The integration of natural plant fibers (NPF) into geopolymer concrete (GPC) remains an underexplored area despite their recognized sustainability benefits. This review critically examines the influence of NPF on the mechanical, durability, and microstructural properties of GPC, emphasizing key factors such as fiber type, content, geometry, and treatment methods. A major novelty of this study is the detailed synthesis of recent advancements in optimizing NPF-reinforced GPC for enhanced performance. Findings indicate that while NPF incorporation reduces density and workability, it significantly improves mechanical properties, with kenaf fiber-reinforced GPC achieving compressive strengths up to 57 MPa and flexural and tensile strengths nearly doubling compared to fiber-free GPC. Additionally, treated NPF contributes to improved durability and microstructural refinement. As well as reducing energy consumption and carbon dioxide (CO2) emissions through using sustainable materials. This study underscores the potential of high-volume, properly treated NPF as a viable strategy for producing more sustainable and high-performance GPC, paving the way for further research into optimal fiber treatments and hybrid reinforcement strategies.

The aim of this work is to investigate the effect of curing temperature and time on the development of compressive strength in geopolymer mortars produced using ground granulated blast-furnace slag (GGBFS) and fly ash (FA). Considering curing circumstances, both the activation energy and the reference temperature could be used properly to build a reliable anticipated model for predicting the compressive strength of geopolymer-based products (mortar and concrete) using maturity-based techniques. In this study, the compressive strength development of geopolymer mortar made from (FA) and (GGBFS) under varying curing conditions. The mortar was prepared using an alkali solution of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) in a 1:1 ratio, with NaOH molarity of 12. Specimens were cast following ASTM C109 standards, with a binder/sand ratio of 1:2.75, and compacted for full densification. FA-based mortar was cured at 40 °C, 80 °C, and 120 °C, while GGBFS-based mortar was cured at 5 °C, 15 °C, and 40 °C for durations of 0.5 to 32 days. Compressive strength was evaluated at each curing period, and data were analyzed using ASTM C1074 procedures alongside a computational model to determine the best-fit datum temperature and activation energy. The Nurse-Saul maturity method and Arrhenius equation were applied to estimate the equivalent age and maturity index of each mix. A predictive model was developed for geopolymer concrete prepared at an alkali-to-binder ratio of 0.45 and NaOH molarity of 12. The final equation demonstrated high accuracy, offering a reliable tool for predicting geopolymer strength under diverse curing conditions and providing valuable insights for optimizing geopolymer concrete formulations.

In recent years, the pursuit of sustainable materials in concrete production has increased, driven by the essentials of environmental conservation, energy efficiency, and resource optimization in construction. Rice husk ash (RHA), distinguished for its abundant silica content, has emerged as a promising biomass-derived material capable of enhancing both the performance and sustainability of geopolymer concrete (GPC) structures. This study undertakes a comprehensive review of literature published between 2014 and 2024, focusing on the chemical composition and physical properties of RHA, and its influence on the physical, mechanical, durability, and microstructural properties of GPC. The results indicated that the addition of a small amount of RHA enhances the strength and durability of concrete, especially with Metakaolin (MK). For instance, the addition of 15 % RHA increases the compressive strength by 21 %. The addition of 20 % RHA reduced the water absorption of GPC by 14 %. Furthermore, the research supports the extensive utilization of treated RHA to counteract the adverse effects associated with conventional cement concrete, thereby fostering greater sustainability in construction practices.

Magnesium oxychloride cement (MOC) is a promising alternative to Portland cement due to its superior mechanical strength and lower carbon footprint. However, its poor water resistance remains a major barrier to widespread use. This review critically evaluates recent and emerging modification strategies to overcome this limitation, with a specific focus on improving water durability through chemical and physical enhancements. The novelty of this work lies in the comprehensive analysis of synergistic effects from compound additives, particularly combinations of organic acids and phosphates, on MOC performance. For example, integrating 1

ABSTRACT Amidst the dual challenges of aggregate scarcity and the environmental impact of carbon dioxide (CO2) emissions from cement production, this study investigates the viability of palm oil clinker (POC) as a sustainable aggregate in geopolymer concrete (GPC). The lack of appropriate alternative coarse and fine aggregates essential in concrete production is one of the critical issues faced by the construction industry. This review evaluates its environmental benefits, chemical and physical attributes, and influence on GPC's microstructure. Previous studies have shown that incorporating POC in GPC significantly reduces density from 2345 to 1821 kg/m3 while maintaining competitive compressive strength, thus proving its applicability in various structural and nonstructural contexts. Moreover, GPC with POC demonstrates enhanced resistance to aggressive environmental conditions such as water absorption and resistance against acid and sulfate environments. Geopolymer mortar (GPM) exposed to sulfate attack recorded the lowest decrease in strength than GPM containing POC fine aggregates by about 20%. The use of 100% POC aggregates in GPC mix has a 3.2% water absorption, which is lower than the limit for high‐performance concrete. The results advocate for the development of POC‐aggregate GPC as an environmentally friendly construction material, contributing to the sustainable advancement of the building industry.

Seeking new sources of renewable construction materials to address the scarcity of sustainable development is still a challenging matter for scholars in all sectors. One of the best solutions to these challenges is using treated desert sand (TDS) as fine aggregate in concrete production. This study aims to enhance concrete's strength and water absorption using different TDS content. To achieve this aim, five concrete mixtures have been prepared with TDS content of 0, 25, 50, 75, and 100% and show their effect on concrete's density, compressive strength, and water absorption. The study's results explored that using 50% TDS instead of natural aggregate recorded the highest compressive strength of 55.45 MPa at 180 days. While the use of 25% TDS recorded the lowest water absorption of concrete, it is only 3.59%. The results obtained from this study indicate that the addition of TDS has a main effect on the strength and durable concrete especially with 25% and 50% replacement levels. This study recommends to use of large amounts of TDS to address the concrete issues and reduce the cost and environmental issues.

Using Polyvinyl alcohol (PVA) fiber and micro silica sand has adverse effects on the economic and sustainable advantages of Engineered Geopolymer Composites (EGCs). This study suggests replacing PVA fiber with polypropylene fiber (PP) in producing sustainable reinforced slag-based-engineered geopolymer composites (SEGC) subjected to thermal cycling and repeated loads. PP and PVA fibers, with a 2% content as a volume fraction were selected to reinforce the EGCs. The study examined mass loss, microstructural characterization, static (monotonic) and cyclic loading measurements, tensile properties, and flexural properties. The results obtained indicate a substantial reduction in the strength of lightweight SEGC under thermal cycling. The density of LW-EGC and ECC composite ranged between 1758 for ECC and 1870 kg/m3 for PVA-EGC, while the statistic stress ranged between 37.35 for PVA-ECC and 63.78 for PVA-EGC. However, the flexural strength under static and cyclic loading of LW-ECC (LW-ECC) samples showed substantial improvement due to the increased reaction rate of fly ash particles under high temperatures. Microstructure analysis revealed that SEGC samples suffered more severe damage than ECC specimens when subjected to various cooling and heating cycles. These micro-cracks contributed to defects in the residual mechanical behavior of lightweight SEGC specimens.

The construction industry faces numerous challenges due to consuming significant energy and huge amounts of natural materials, mainly in concrete production. This study explores the possibility of using iron ore tailings (IOT) as a fine aggregate in concrete, focusing on engineering and environmental perspectives. By partially or fully replacing traditional fine aggregate with IOT, the study aims to improve concrete properties while addressing the ecological challenges of waste management. This study was developed by collecting papers from the Scopus database for the duration between 2000 and 2024. The results show that IOT particles have enhanced concrete's physical, mechanical, durability, and microstructure properties and decreased environmental issues by reducing waste accumulated in landfills and converting them to useful materials. The addition of IOT as fine aggregate reduced the workability in most cases and increased the strength of concrete, especially with low replacement levels. Further studies are recommended to increase the potential use of IOT in concrete production.

The growing demand for sustainable construction materials has motivated the exploration of raw desert sand (RDS) as an alternative fine aggregate in concrete production. This study investigates the influence of RDS, combined with supplementary cementitious materials (fly ash and silica fume), on the long-term mechanical, durability, environmental, and economic performance of concrete at 270 days. Five concrete mixtures were designed with varying RDS replacement levels (0

The increasing demand for building construction and infrastructure projects has led to the release of huge quantities of carbon dioxide (CO2) emissions, heightened energy consumption, and increased environmental pollution. The depletion of vital concrete materials due to construction activities exacerbates these emissions. This review explores the influence of different seashell proportions, as aggregate replacements, on concrete performance. It comprehensively examines the physical, chemical, mechanical, and durability properties of concretes incorporating seashells, synthesizing current research covering from 2000 to 2025. The findings reveal a positive correlation between the use of seashell aggregates and enhanced mechanical strength in concrete. Calcium oxide (CaO) constitutes the highest percentage among other components in seashells. In most cases, the addition of seashells as aggregates reduced workability and density and increased the strength of concrete. For instance, workability was reduced from 40.6 to 15 mm due to the addition of 50 % as aggregate. The compressive strength increased from 25 to 30 MPa due to the addition of 10 % cockle shells as aggregate, while it decreased with high replacement levels. Thus, it is concluded that seashells possess significant potential as sustainable concrete materials and enhance the waste management process. The results support the widespread adoption of seashells in the production of sustainable concretes.

The application of nanotechnology in the construction industry can solve numerous environmental issues by effectively utilizing large quantities of waste materials generated during construction. Applying nanotechnology in the cement concrete industry has led to numerous benefits. The adoption of nanotechnology in cement mortar and concrete results in significant improvements in properties such as workability, compressive, flexural, and tensile strengths, as well as water absorption, chloride ion permeability, and shrinkage. Hence, the utilization of nanotechnology can enhance environmental sustainability in construction materials by incorporating significant amounts of waste materials as supplementary cementitious materials. This practice not only reduces the emissions of carbon dioxide (CO2) resulting from the accumulation of waste in landfills but also reduces cement production. By advocating for the integration of nano-waste materials in significant volumes within construction materials, this research underscores the pathway towards sustainable construction practices. Such endeavors align with the broader objective of contributing to the attainment of the sustainable development Goals (SDGs), particularly in protecting the environment and combating climate change.

The current study investigates the effect of dune sand (DS) and fly ash (FA) on the microstructure of fiber-reinforced concrete (FRC). Concrete is a widely used construction material, and understanding its behavior under different conditions is important for optimizing its performance. The use of alternative materials, like FA and DS, in concrete production has gained attention due to their abundance and potential environmental benefits. The research methodology involved the preparation of FRC mixes with different combinations of FA and DS, along with varying fiber content. The microstructural analysis of the samples was conducted through scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The findings revealed that the addition of FA and DS influenced the microstructure of the FRC. Furthermore, the inclusion of FA contributed to improved pore structure and enhanced the pozzolanic reaction, resulting in a denser microstructure. The incorporation of steel and basalt fibers demonstrated significant effects on the microstructure of the concrete. The results provide valuable insights for optimizing the design and performance of concrete structures in arid regions while considering sustainable materials.

This research employs response surface methodology (RSM) to optimize and model ultra-high-performance concrete (UHPC) formulations, integrating desert sand and varying proportions of supplementary cementitious materials (SCMs), specifically fly ash (FA) and ground granulated blast furnace slag (GGBS). By investigating the influence of desert sand and SCM contents, the study aims to discern their impact on the workability and 7-day compressive strength of UHPC. Employing a central composite design (CCD), thirteen separate mixes were formulated. Key responses, namely workability and compressive strength, were evaluated. The developed models underscore the enhancement in UHPC performance through the partial replacement of cement with SCMs. Notably, an optimal combination of 75% desert sand and 30% SCMs resulted in a workability of 69.4 mm and a 7-day compressive strength of 46.01 MPa. The findings emphasize the potential for eco-friendly concrete in the construction industry, also prompting further exploration into long-term strength and higher SCM concentrations.