Effect of Elevated Temperature on the Compressive Strength of Recycled Aggregate Concrete (original) (raw)

Effect of elevated temperature on the compressive strength of concrete element with recycled aggregate was investigated. Natural aggregates were replaced with recycled aggregates during casting at 0, 25, 50, 75 & 100 percentages using water cement ratio of 0.60.The natural aggregates used were quarried granites from parent igneous rock with maximum sizes of 19mm. While the recycled aggregates were gotten from demolished old concrete building, crushed manually and sieved to also get maximum sizes of 19mm.Total of 75 concrete cubes of 150mm x 150mm sizes were cast and properly cured for 28 days. The concrete cubes were then subjected to different level of temperatures (50°c, 100°c, 200°c, 300°c, and 400°c) for a period of eight (8) hours in the electronic oven. Test results showed an average of38% reduction in strength for all percentage replacements with recycled aggregates within temperature ranges not above 200°c compare to about 25% reduction in strength of samples with 100% natural aggregates. For temperature ranges between 300°c and 400°c, an average of 55% reduction in strength was observed for samples with various percentage replacements with recycled aggregates.