Mechanical properties of shielding concrete with magnetite aggregate subjected to high temperature

摘要

This paper presents an experimental study on the performance of shielding concrete with magnetite aggregate subjected to high temperature. Two concretes with magnetite aggregate and one ordinary concrete with natural aggregate were tested. Mechanical properties were studied at ambient temperature and after thermal exposure. Compressive strength and splitting tensile strength have been tested. For each test, the specimens were heated at a rate of l°C/min up to different temperatures (300, 450, 600 and 800°C). In order to ensure a uniform temperature throughout the specimen, the temperature was held constant at the target temperature for 1 h before cooling. In addition, the specimen mass was measured before and after heating in order to determine the weight loss of tested samples. Studies have shown that use of magnetite aggregate can diminish the negative impact of elevated temperatures on mechanical properties of concretes.