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.

A new type of stiffening rib is proposed to improve the mechanical performance of T-shaped concrete-filled steel tubular (CFST) columns. A finite element model was established using the general-purpose commercial software ABAQUS 2022. After verification through comparison with experimental data, the developed finite element model was employed to numerically evaluate the performance of T-shaped CFST short columns with stiffening ribs under axial compression. The results indicated that the new stiffening ribs are capable of significantly reducing the buckling deformation of the steel tube, enhancing the confinement effect of the steel tube on the core concrete, and improving the combined performance of the steel tube and the concrete. The thickness and material strength of the stiffening ribs had a notable impact on the ultimate bearing capacity and ductility of the short column specimens. When the thickness of the stiffening ribs increased from 5 mm to 8 mm, the ultimate bearing capacity correspondingly increased by 10.51% to 31.77%, while the ductility coefficient improved by 6.48% to 17.20%. When the steel strength increased from 262.50 MPa to 345 MPa and 390 MPa, the ultimate bearing capacity correspondingly increased by 17.36%, 19.78%, and 30.50%, and the ductility coefficient improved by 12%, 13.87% and 23.92%. The changes in the specifications and arrangement of the stiffening ribs had no significant effect on the ultimate bearing capacity and ductility of the specimens. The change in angle steel specifications caused variations in ultimate bearing capacity within ±5% and variations in the ductility coefficient within ±10%. Changes in the arrangement caused variations in ultimate bearing capacity within ±1% and variations in the ductility coefficient within ±5%.

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.

The bond between steel bars and concrete is a fundamental aspect of reinforced concrete, ensuring the efficient transfer of forces between the two materials and guaranteeing their compatibility and composite action. The conventional equation for calculating bond stress does not account for slip effects. However, significant slip can lead to considerable errors, which are disadvantageous when analyzing bond performance using finite element methods. To address this issue, this study proposed a modified bond stress calculation model, whose reliability was systematically validated through pull-out tests and comparative analysis with a CEB-FIP model. The experimental program employed a universal testing machine for load application, with a static strain measurement system continuously monitoring stress–strain data throughout the loading process. The experimental results indicated that the failure process of the specimens could be categorized into the following, four distinct stages: micro-slip stage, slip stage, descent stage, and residual stage. The discrepancy between bond stresses calculated by the modified and conventional equations increased with the increasing relative slip, reaching its maximum value in the residual stage. A comparative analysis of 23 groups of experimental data from the literature was performed, revealing that the difference in bonding stress reached a maximum of 20.45% in the residual stage, with a standard deviation (S) of 0.006 and a coefficient of variation (C_v) of 0.321, reflecting small fluctuations but large dispersion. In contrast, the S of the residual bonding stress was 0.016, and the C_v was 0.080, showing lower dispersion but greater volatility. Further comparison with the CEB-FIP model confirmed the superior applicability and computational accuracy of the proposed modified model. Therefore, the modified equation should be utilized for calculating bond stress when significant slip occurs, particularly during the residual stage.

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.