Engineering Properties of Concrete made with Pulverised Fly Ash

This research work reports the potential of using Pulverised Fuel Ash (PFA) as a partial substitute for Portland Cement (PC) in the development of concrete. PFA is a by-product of the combustion of pulverized coal in electric power generating plants. Its use in concrete will alleviate the environmental concern for PFA disposal and ease the growing shortage and increasingly high cost of PC. In order to investigate the cement replacement potential of PFA, six types of mixes, at varying PFA replacement levels were designed— 5%, 10%, 15%, 20%, 25% and 30%; all with a water binding ratio of 0.6 and tested at 7, 14, and 28 days. The testing programme included material characterization; the determination of slump value and compressive strength. The results showed that the addition of PFA to the concrete mix causes the compressive strength to reduce at early age and that the slump values increased as the quantity of PFA increased in the mix.