Study of Compressive Strength of Concrete with Coal Power Plant Fly Ash as Partial Replacement of Cement and Fine Aggregate FAREED AHMED MEMON*, NAFEES AHMED MEMON**, AND RIZWAN ALI MEMON** RECEIVED ON 09.03.2010 ACCEPTED ON 04.10.2010 ABSTACT This research study comprises of concrete cubes made with OPC (Ordinary Portland Cement) and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of this study, total 81 concrete cubes were cast. Among 81 cubes, 9 cubes were made with normal concrete, 36 cubes were made by replacing 25, 50, 75 and 100% of fine aggregate with fly ash and 36 cubes were made by replacing 10, 25, 50, and 75% of cement with fly ash. The cubes were 6"x6" in cross-section, and the mix design was aimed for 5000 psi. After proper curing of all 81 cubes, they were tested at 3, 7 and 28 days curing age. The cubes were tested in Forney Universal Testing Machine. By analyzing the test results of all the concrete cubes, the following main findings have been drawn. The compressive strength of concrete cubes made by replacing 100% fine aggregate by fly ash was higher than the concrete cubes made with OPC at all 3, 7 and 28 days curing ages. On the other hand, the compressive strength of concrete cubes made by replacing 10 and 25% cement by fly ash was slightly lower than the concrete cubes made with OPC at all curing ages, whereas, the compressive strength of concrete cubes made by replacing 50 and 75% of cement by fly ash were quite lower than the concrete cubes made with OPC at all curing ages. Key Words: OPC, Fly Ash, Fine Aggregate, Concrete Cubes. * Assistant Professor, and ** Associate Professor, Department of Civil Engineering, Mehran University of Engineering & Technology, Jamshoro. 1. INTRODUCTION C oncrete is a composite material which is being used in variety of structures. More commonly the construction material like aggregates, cement, and steel bars are to be transported from distant places to the site which is quite expensive. Therefore, the aggregates are preferably to be used available in the vicinity. Fly ash is fine residue material resulting from the combustion of powdered coal in power generation plants. This waste by-product must be effectively disposed to eliminate air, soil, and surface, as well as ground water pollution at added cost to the industry and thus to the society [1-3]. MEHRAN UNIVERSITY RESEARCH JOURNAL OF ENGINEERING & TECHNOLOGY, VOLUME 29, NO. 4, OCTOBER, 2010 [ISSN 0254-7821] 647