Durability properties of high-strength concrete with high-volume bottom ash as a substitute for cement and fine aggregate

This research explores the impact of using high-volume processed bottom ash as a substitute for cement and sand in high-strength concrete production, with a particular focus on durability. The study specifically assesses the durability of concrete by evaluating its resistance to chloride penetration, corrosion, and permeability. Initially, the study investigated the use of ground bottom ash (GBA) as a low and high volume cement replacement by varying the GBA content to 35 %, 50 %, and 65 % by weight. In the second phase, the focus shifted to promoting the reutilization of bottom ash as a sand replacement. This involved incorporating specimens with 50 % GBA, identified as the optimal cement replacement ratio from the initial phase, and replacing 60 % of the sand with coarse bottom ash (CBA). The findings indicated that durability properties improved with an increase in GBA content up to 50 %, correlating with increased compressive strength. However, increasing GBA content to 65 % and combining 50 % GBA with 60 % CBA showed negligible effects on the durability of high-strength concrete, despite a reduction in strength. In summary, the optimal GBA amount for cement substitution in high-strength concrete was 50 % by weight, leading to the highest compressive strength of 84.5 MPa at 90 d, the least weight loss from steel corrosion, and the lowest permeability.