Sustainable Soil–Cement Composites with Rice Husk Ash and Silica Fume: A Review of Performance and Environmental Benefits
Xiaosan Yin, MD Rashedur Rahman, Yuzhou Sun, Yi Zhao, Jian Wang
Abstract
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.