The resistance of high strength concrete with diatomaceous earth exposed to high temperatures

Abstract

Diatomaceous earth is one of cementitious material. In this study diatomaceous earth was used as cement replacement in high strength concrete mixture at 0%, 5%, 10% and 15% replacement levels. The concrete specimens were then exposed to three different temperatures, namely 400oC, 500oC and 600oC for 5 hours. The change in surface appearance, the loss in mass and the degradation in compressive strength of concrete specimens after being exposed to those temperatures were examined. All the specimens exposed to the temperature of 400oC did not have any visible crack at their surfaces. However there was the appearance of many cracks at the specimen surfaces after being exposed to the temperatures of 500oC and 600oC. The mass loss and compressive strength degradation increased with increasing the exposed temperature. Furthermore, the high strength concrete with diatomaceous earth experienced smaller compressive strength degradation compared to that without diatomaceous earth. The smallest compressive strength degradation was found at the mixture with 15% replacement level.