EXPERIMENTAL INVESTIGATION ON MECHANICAL PROPERTIES OF HIGH -PERFORMANCE CONCRETE WITH PARTIAL REPLACEMENT OF CEMENT BY FLY ASH

Improving on our construction practices to promote sustainable development in engineering and to promote eco-friendly living is vital in the fight against global warming and associated problems. This study looked at one of the ways in which engineering can contribute to this fight through promoting the recycling of waste by-products such as fly ash, on a larger scale in the cement and concrete industry, by utilizing the Fly Ash to the optimum. In this study, high-performance concrete mixes 50 MPa with Fly Ash partially substituting the cement at 10%, 20%, 30%, and 40% were produced and numerous tests were performed to determine the optimum amount of Fly Ash that can be used and still obtain better or comparable concrete to ordinary concrete. In addition, a cost comparison between high-performance concrete and high-performance concrete with Fly Ash content was undertaken. Testing for concrete properties was conducted under laboratory conditions over a period of 7days and 28days. The trial mix was prepared for characteristics strength of 50MPa with water to cement ratio of 0.30. That increase in Fly Ash content influenced the properties of fresh concrete favorable and the recorded slump increased with the increase of Fly ash content. The results of compressive strength replaced 30%FA concrete increased by10.02MPa or 15.25 % as compare at 28days of normal concrete and 40%FA concrete increased by 2.61MPa or 4.35 % as compare at 28days of target mean strength, the results of splitting tensile strength replaced 40%FA concrete increased by 1.12MPa or 21.25 as compare at 28days of normal concrete, and the results of flexural strength replaced 40%FA concrete increased by 1.27MPa 19.36 % as compare at 28days of to normal concrete. The mixes increase with fly ash replacement has a lesser rate of increase in strength from 7days to 28days through they have high initial strength than the mixes with fly ash as replacement of cement. Increasing the Fly Ash content can also significantly reduce the cost of producing concrete ingredients. The practice of utilizing increase Fly Ash content in concrete can be beneficial for the construction of concrete industry without compromising the quality of the concrete product structures.