An experimental investigation on mechanical, durability and Microstructural Properties of high-volume fly ash based concrete

Concrete is a frequently used construction material in the world. The usage of high content cement may lead to early age cracks and heat of hydration. To overcome this, High-Volume Fly ash (HVFA) is used in the present experimental work to substitute cement at 0%, 25%, 50%, and 70%. The conventional concrete compared with HVFA at curing 7, 14, 28, 56, and 90 days. Mechanical and durability tests were conducted to study the performance, and microstructure characteristics were analysed durability tests like Rapid chloride penetration test (RCPT) water absorption sorptivity tests done on mixes. The mechanical strength of HVFA based concrete is optimised at 50% fly ash dosage. At this, the durability of mixtures also improved due to the development of C-S-H gels leading to a reduction in porosity. These characteristics improved by increased duration of curing. At 90 days, concrete’s porosity (in terms of chloride ion penetration) was moderately reduced compared to 28days. The water absorption levels in the mixes also highly decreased at 90 days of curing compared to other periods (7, 14, 28, 56 and 90 days). The reduction in the peaks of quartz and mullite in the XRD pattern from 7 days to 90 days represents the decrease of void content and development of the C-S-H gels in this matrix of the concrete. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.