Influence of Accelerators on cement replacement by large volumes of Fly ash to achieve early strength

Abstract

The chemical admixtures named as accelerators improve the early setting and strength of cementations products whereas theh Cement prepared with large volumes of Fly ash (Pozzolana) fetch the durability and better sustainability. Achieving High early strength as well as durability in cementations products is a tough and challenging job which provokes the idea of the addition of accelerators to cement prepared with large volumes of Fly ash (pozzolana). The present study investigated the early setting and strength enhancement of Ordinary Portland Cement (OPC) replacement with 30, 40 and 50% of Fly ash when mixed with the accelerating admixtures such as Calcium nitrate (Ca(NO3)2) and Calcium nitrate (Ca(NO3)2) combination with Triethanolamine (C6H15NO3) at temperature of 25 ± 5 °C and 58±5 % relative humidity. In early ages, the maximum compressive strength was noted for 30 % Fly ash with 1% of Ca(NO3)2 in combinations with 0.05 % of C6H15NO3 and the achieved percentages noted as 18.23% and 54.29% for 1 and 3 days. The microstructural property (SEM) was also determined for OPC replacement with 30% of Fly ash at 1 and 3 days for 1% of Ca(NO3)2 in combination with 0.05, 0.1, 0.15 and 0.2% of C6H15NO3.