Experimental Investigation Of The Effect Of Pond Ash On High Strength Concrete

Abstract

As the demand for infrastructure increases, there is a corresponding increase in material consumption. High rise structures require high strength concrete to withstand high compressive loads and increase their design life. To achieve this, the highest quality of fine aggregates, such as river sand, is used to improve the concrete strength. However, this has resulted in a scarcity of river sand in developing countries over time. In order to reduce this impact, pond ash has been partially used to replace fine aggregate. The objective of this study was to examine how partially replacing fine aggregate with pond ash affects the workability and mechanical properties of high strength concrete. For the C-45/55 grade of concrete, a control mix and five different mixes were prepared, each containing a replacement of fine aggregate with pond ash ranging from 0% to 25%. The workability of the fresh concrete was measured by its slump, which was found to decrease as the percentage of pond ash increased. This is because pond ash has a high absorption capacity. The mechanical strength test results for high strength concrete, where fine aggregate was partially replaced by pond ash, showed that there was an increase in compressive strength at 28 days by 5.40% for 5% of pond ash, 1.30% for 10% of pond ash, and a reduction in compressive strength by 2.26% for 15% of pond ash, when compared to the ES EN 1992 standard. Similarly, the splitting tensile strength test results at 28 days showed an increase in strength by 3.64% for 5% of pond ash, 0.81% for 10% of pond ash, and a reduction in strength by 3.04% for 15% of pond ash, compared to the ES EN 1992 standard. Therefore, it can be concluded that replacing up to 10% of fine aggregate by weight with pond ash fulfils the compressive strength and splitting tensile strength requirements of the ES EN 1992 code of standards.