Mechanical performance and life cycle assessment of BFRP-reinforced AAC slabs strengthened with basalt macro-fibers

Abstract

Steel-reinforced Ordinary Portland Cement (OPC) concrete is the predominant construction material; however, it faces critical challenges, notably steel corrosion and high CO₂ emissions from cement production. Recent research explores corrosion-resistant alternatives to steel and environmentally sustainable substitutes for OPC. Basalt Fiber Reinforced Polymers (BFRP) bars demonstrate promising corrosion resistance, while alkali-activated cements (AACs) offer a lower-emission alternative to OPC. However, reinforced concrete slabs with BFRP bars exhibit lower shear capacity, wider crack widths, and more significant deflections compared to steel-reinforced slabs. Integrating wave-shaped Basalt-Macro fibers (BMFs) into the concrete mix can enhance these properties. This study assesses the structural and environmental viability of combining BFRP reinforcement with AAC. Experimental testing involved investigating the behavior of six BFRP-reinforced AAC slabs with varying BMFs contents (0 %, 1.5 %, and 2 %) compared to a steel-reinforced OPC control slab. The findings revealed that adding the BMFs increased the cracking load, shear capacity, and flexural stiffness of BFRP AAC slabs. Furthermore, a life cycle assessment (LCA) showed that BFRP-reinforced AAC slabs are significantly more sustainable than steel-reinforced OPC concrete, which produces 292 % and 190 % more CO2 emissions than BFRP-reinforced AAC slabs without and with 1.5 % fibers, respectively. This highlights the environmental advantages of using BFRP and AAC in construction.