Sustainable Development of High-Volume Fly Ash Self-Compacting Concrete Incorporating Bottom Ash and Recycled Concrete Aggregates

Abstract

Incorporating by-products like coal bottom ash (BA), recycled concrete aggregates (RCA), and fly ash (FYA) in concrete is an essential step toward green and sustainable development in construction sector. For sustainable utilization of RCA as natural coarse aggregates (NCA) and BA as natural fine aggregates (NFA) in high-volume fly ash self-compacting concrete (HVFYA-SCC), this study investigates ten numbers of designed HVFYA-SCC mixes. HVFYA-SCC mixes were developed with varying content of ordinary Portland cement, FYA (60%), NCA, NFA, RCA (maximum 50%) and BA (maximum 30%). The substitution of 20% BA and 25% RCA in HVFYA-SCC mixes increased compressive and split tensile strengths after 120 days of curing, while further substitution (s) led to a drop in properties. Similarly, at 120 days of curing the maximum electrical resistivity was achieved (20% BA and 25% RCA), while all mixes under ultrasonic pulse velocity resulted in the ‘good category.’ Also, the same mix resulted in lower sorptivity values for maximum curing. A good correlation (R2 0.8) was observed among the tested mechanical and durability properties. The outcomes of this study indicate valuable information on the performance and potential benefits of using HVFYA-SCC in advanced structural designs for upcoming concrete industry. Furthermore, the findings successfully support the implementation of designed concretes as sustainable and environmentally-friendly alternative to conventional concrete(s).

Keywords

• high-volume fly ash self-compacting concrete
• coal bottom ash
• recycled concrete aggregates
• durability properties