Effects of high temperatures on the behavior of reactive powder concrete based on recycled brick powder

Reactive powder concrete is a new type of high strength cement-based composite materials that are characterized by high compressive strength levels. In recent times, the introduction of the reactive powder concrete has opened new horizons for engineers and researchers. The present experimental study aims primarily to investigate the behavior of recycled reactive powder concrete from finely ground local waste raw materials. In this study, local construction and demolition waste (waste brick powder, waste marble powder) are used for the full replacement of silica fume and quartz powder in Portland cement, in addition to fine sand, superplasticizer, and water. In addition, a number of test samples were prepared and subjected to elevated temperatures of 20, 200, 500, and 800 °C. After a fixed period of exposure, the weight losses were determined, and then the compressive and flexural strength as well as the porosity tests were performed. The results obtained indicated that the weight of all samples significantly decreased as the exposure temperature went up. The weight drop was particularly significant above 500 °C. It should also be noted that the effect of the water-to-cement (W/C) ratio and the type of addition on the weight loss were not particularly important. Moreover, the findings also revealed that the compressive strength of the formulated concrete decreased as the exposure temperature increased. In addition, it was found that high temperatures had a significant impact on concrete mixtures incorporating red brick waste.