Engineering Properties of Concrete Mixed with Varying Degrees of Fly Ash

摘要

The rate of carbon dioxide emission is on the high side globally an d very few of this emission are being used. Bulk of this emission comes from cement manufacturing industries. There is urgent need to look for alternatives to cemen t in other to preserve natural resources globally. This study is aimed at determining the possibility of fly ash as substitute for cement in concrete production. In this study, ordinary Portland cement (OPC) and fly ash were obtained from Lafarge Group Nigeria Limited, Ewekoro Cement Plant, Itori, along Lagos-Abeokuta Express way, Ogun State, Nigeria. Cement was rep laced with fly ash at 5%, 10%, 15%, 20% and 25% to determine the workability characteristics, with 0% serving as control. Concrete cubes in ratio of 1:2:4 were prepared in accordance with BS 1881 parts 1 -4, 1970, part 6, 1971 and crushed at 28 days and 90 days to determine the compressive strength . From the result of this study, the fly ash of about 20% showed similar characteristics to that of normal concrete. It shows the possibility of using up to 20% fly ash in concrete for normal concrete works. It is therefore evidently clear that cement could be replaced with fly ash in engineering construction works. Therefore, environmental risks and hazard associated with cement production would be greatly reduced.