Utilization Of Fly Ash From Maasim Coal-Fired Power Plant In Concrete Hollow Block Application

This study investigated the effect of replacing, by percentage, cement with fly ash from Maasim Coal-Fired Power Plant in the compressive strength of concrete hollow blocks (CHB). The percentages of replacements were 10%, 20%, 30%, 50% and 70%, with a control sample of 0% cement replacement. Three samples per percentage per curing age where made for experiment. The study was originally designed to also test a 100% replacement of cement, but the samples made with full replacement were so soft and can't bear loading, so the data were not included in the final papers. The compressive strength tests were performed on 4-inch thick concrete hollow block samples in curing ages: 7, 14 and 28 days. After reaching the desired curing age, the CHB samples were then subjected to compressive strength test using a crushing machine. The compressive strength of each sample was determined, and then averaged according to percentage of cement replacement. The results were then graphed and analyzed. It was found out that Mix 3, with 20% replacement of cement, gained the highest compressive strength of 2.84 mpa after 28 days; while the control sample, Mix 1, gained 2.7 mpa, as well as Mix 2 (10% replacement). Mix 6 with 70% cement replacement gained the lowest strength of 0.81, making it an unsuitable mixing. This study proved that the fly ash by-product of the Maasim Coal-Fired Power Plant can be a suitable replacement of cement in concrete hollow block production to increase its Compressive strength; and that the optimum replacement of cement by percentage is 20%.