The construction industry urgently requires sustainable alternatives to conventional cement to mitigate its environmental footprint, which includes 8% of global CO₂ emissions. This review critically examines the potential of rice husk ash (RHA) and silica fume (SF)—industrial and agricultural byproducts—as high-performance supplementary cementitious materials (SCMs) in soil–cement composites. Their pozzolanic reactivity, microstructural enhancement mechanisms, and durability improvements (e.g., compressive strength gains of up to 31.7% for RHA and 250% for SF) are analyzed. This study highlights the synergistic effects of RHA/SF blends in refining pore structure, reducing permeability, and enhancing resistance to chemical attacks. Additionally, this paper quantifies the environmental benefits, including CO₂ emission reduction (up to 25% per ton of cement replaced) and resource recovery from agricultural/industrial waste streams. Challenges such as material variability, optimal dosage (10–15% RHA, 5–8% SF), and regulatory barriers are discussed, alongside future directions for scalable adoption. This work aligns with SDGs 9, 11, and 12, offering actionable insights for sustainable material design.

This study investigates the synergistic modification of cement–soil using waste brick powder (WBP) and polyvinyl alcohol (PVA) fibers to address the growing demand for sustainable construction materials and recycling of demolition waste. An orthogonal experimental design was employed with 5% WBP (by mass) and PVA fiber content (0–1%), evaluating mechanical properties based on unconfined compressive strength (UCS) and splitting tensile strength (STS) and microstructure via scanning electron microscopy (SEM) across 3–28 days of curing. The results demonstrate that 0.75% PVA optimizes performance, enhancing UCS by 28.3% (6.87 MPa) and STS by 34.6% (0.93 MPa) at 28 days compared to unmodified cement–soil. SEM analysis revealed that PVA fibers bridged microcracks, suppressing propagation, while WBP triggered pozzolanic reactions to densify the matrix. This dual mechanism concurrently improves mechanical durability and valorizes construction waste, offering a pathway to reduce reliance on virgin materials. This study establishes empirically validated mix ratios for eco-efficient cement–soil composites, advancing scalable solutions for low-carbon geotechnical applications. By aligning material innovation with circular economy principles, this work directly supports global de-carbonization targets in the construction sector.

To address environmental concerns and promote the sustainable development of building materials, an investigation was conducted on the effects of incorporating waste glass powder (WGP) and varying proportions of basalt fiber and glass fiber on the compressive strength of cement-soil. Unconfined compressive strength tests were performed at different curing ages to analyze the interaction between WGP and fiber types on cement-soil performance. The results demonstrate that while WGP initially reduces the compressive strength of cement-soil, it significantly improves compressive strength when combined with optimal fiber content. In particular, the compressive strength of cement-soil increases within the range of 0%–1.5% basalt fiber content, with the maximum compressive strength achieved at 1.5% basalt fiber content. For glass fiber, the compressive strength of cement-soil initially increases and then decreases with increasing fiber content, with the best performance observed at 2.0% glass fiber content after 28 days of curing. A predictive model that integrates fiber content and curing age was developed to accurately predict the compressive strength of WGP cement-soil, providing a valuable tool for practical engineering applications.

To address the inadequate mechanical properties of cement-treated soils containing waste brick powder (WBP) and to promote the recycling of construction waste, an orthogonal experimental design was adopted. This study investigated the effects of basalt fiber content (0%-2%) and WBP content (0%-20%) at curing ages of 3, 14, and 28 days. Unconfined compressive strength (UCS) and splitting tensile strength tests were conducted, and the underlying micro-mechanisms were analyzed using scanning electron microscopy (SEM). The results indicated that the pozzolanic reaction of WBP significantly improved the later-age strength of the cement-treated soil. At 28 days, the UCS of the specimens with 10% WBP increased by 38.3% compared to the plain cement-treated soil. The incorporation of basalt fibers effectively reduced material brittleness, with a maximum increase of 56.0% in splitting tensile strength, and the failure mode transitioning from brittle fracture to ductile failure. Range analysis revealed that the influence on strength follows the order: cement content > WBP content > fiber content, and the optimal mix proportion under the experimental conditions was identified. To simultaneously optimize compressive and tensile properties, grey relational analysis was introduced for bi-objective optimization. The results showed that, in the single-objective grey analysis for compressive performance, the grey relational degrees between the individual factors and the mechanical property ranked as follows: cement content > WBP content > fiber content, which is consistent with the results of the range analysis. In the simultaneous bi-objective optimization, the optimal parameter combination was determined as cement content of 20%, fiber content of 1.0%, and WBP content of 0.5%. Microstructural analysis showed that the fibers formed a three-dimensional network within the matrix, effectively restraining crack propagation. Meanwhile, the pozzolanic activity of the WBP worked synergistically with fiber reinforcement to refine the pore structure. These research findings provide a solid theoretical basis for the recycling of construction waste and the development of high-performance, green construction materials.

Cement-stabilized soil is widely used for ground improvement but suffers from brittleness and low tensile strength. This study investigates a sustainable composite integrating waste brick powder (WBP, 5%) and glass fiber (GF, 0–2.0%) to enhance mechanical performance and microstructural integrity. Unconfined compressive strength (UCS), splitting tensile strength (STS), and scanning electron microscopy were evaluated at 3, 14, and 28 days. Results reveal stress-state-dependent reinforcement: UCS peaked at 2.0% GF with gains of 18.1%, 7.3%, and 9.1%, while STS maximized at 1.5% GF (43% increase), declining 14.3% at 2.0% due to fiber agglomeration. Post-peak ductility improved markedly, with the residual strength ratio increasing from 12.4% to 43.2% and the ductility index from 1.18 to 1.85. Microstructural analysis confirmed that uniform fiber dispersion enables crack bridging and interfacial load transfer, whereas agglomeration creates localized weak zones. The composite avoids approximately 85 kg CO₂eq per cubic meter by valorizing construction waste. These findings establish quantitative, stress-state-dependent design guidance for sustainable cement-stabilized soil composites.

To address the inadequate mechanical properties of cement-treated soils containing waste brick powder (WBP) and to promote the recycling of construction waste, an orthogonal experimental design was adopted. This study investigated the effects of basalt fiber content (0%-2%) and WBP content (0%-20%) at curing ages of 3, 14, and 28 days. Unconfined compressive strength (UCS) and splitting tensile strength tests were conducted, and the underlying micro-mechanisms were analyzed using scanning electron microscopy (SEM). The results indicated that the pozzolanic reaction of WBP significantly improved the later-age strength of the cement-treated soil. At 28 days, the UCS of the specimens with 10% WBP increased by 38.3% compared to the plain cement-treated soil. The incorporation of basalt fibers effectively reduced material brittleness, with a maximum increase of 56.0% in splitting tensile strength, and the failure mode transitioning from brittle fracture to ductile failure. Range analysis revealed that the influence on strength follows the order: cement content > WBP content > fiber content, and the optimal mix proportion under the experimental conditions was identified. To simultaneously optimize compressive and tensile properties, grey relational analysis was introduced for bi-objective optimization. The results showed that, in the single-objective grey analysis for compressive performance, the grey relational degrees between the individual factors and the mechanical property ranked as follows: cement content > WBP content > fiber content, which is consistent with the results of the range analysis. In the simultaneous bi-objective optimization, the optimal parameter combination was determined as cement content of 20%, fiber content of 1.0%, and WBP content of 0.5%. Microstructural analysis showed that the fibers formed a three-dimensional network within the matrix, effectively restraining crack propagation. Meanwhile, the pozzolanic activity of the WBP worked synergistically with fiber reinforcement to refine the pore structure. These research findings provide a solid theoretical basis for the recycling of construction waste and the development of high-performance, green construction materials.