Eco-durability impact of rice husk ash and hybrid fibers on high-performance fiber-reinforced densified concrete

Abstract

The use of supplementary cementitious materials (SCMs) has gained significant attention in recent years as a strategy to enhance the sustainability and durability of concrete while reducing its environmental footprint. Therefore, this research aims to investigate the performance of high-performance fiber-reinforced concrete (HPFRC) incorporated with rice husk ash (RHA) and hybrid fibers (HFs), focusing on durability, SCMs, and environmental impact. HPFRC compositions with varying RHA (10%, 20%, and 30% by weight) and HF (0.4%, 0.8%, and 1.2%, 1.6% by volume) contents were investigated. Moderate RHA proportions (e.g., 10–20%) improved electrical resistivity, while a balance of RHA and hybrid fibers helped moderate the increase in water absorption typically associated with RHA's hydrophilic nature. Sustainability indicators demonstrated that RHA could reduce global warming potential and embodied energy indices by 25.6% and 24.5%, respectively, whereas the HFs increased them by 57.4% and 190.7%, respectively, highlighting the balance between mechanical performance and environmental sustainability. Combining RHA and HFs in the densified mixture design algorithm is a promising approach for creating durable, mechanically strong, and environmentally friendly concrete. These findings are expected to promote sustainable concrete development and future construction material innovations.