Assessment on durability of lightweight concrete using alkali modified fly ash based atrificial coarse aggregate (FACA)

Abstract

Thermal power plant is the backbone of India’s energy generation comprising of more than 50%. Since Indian coal is of low grade with ash content of the order of 30–55% in comparison with imported coal which has low ash content of the order of 3–15%, huge piles of fly ash is left over which poses environmental degradation. In order to reduce its harmful effects on environment, we have to reuse/recycle this industrial by-product. As concrete contains 80% coarse aggregate, huge quantity of fly ash waste can be utilized if we reuse it as artificial coarse aggregate. This work compiles the results of a pilot scale study on durability properties of concrete made from fly ash-based artificial coarse aggregate (FACA). The molarity of NaOH, NaOH-to-Na2SiO3 ratio and alkaline-solution-to-fly-ash ratio used in this research are 8 M, 0.5 and 0.4 respectively. The coarse aggregate is produced by crushing the geopolymer mass in a crusher. The fundamental durability properties of the concrete (FACACRETE) prepared from FACA is compared with the conventional concrete (using crushed granite stone) at M20, M25 and M30 grades of concrete. It is observed that on increasing the grade of concrete, the ultrasonic pulse velocity test gives better result for both conventional concrete and FACACRETE. © 2022 Taylor & Francis Group, LLC.