Direct tensile behavior of normal-strength concrete at elevated temperatures

摘要

The objective of this study is to determine the tensile properties of normal-strength concrete (NSC) at elevated temperatures through direct tensile tests. The specimens were cast in cylindrical cross sections with extended ends according to RILEM TC 129-MITT After curing, the specimens were heated in a tubular electric furnace at temperatures up to 800 degrees C (1472 degrees F) and then subjected to direct tension under that temperature. At 800 degrees C (1472 degrees F), there is a strength loss of 73% and elastic modulus reduces by 93%. Peak strain increases with increasing temperature up to 700 degrees C (1292 degrees F) and then shows slight reduction between 700 and 800 degrees C (1292 and 1472 degrees F). Complete tensile stress-strain relationships of NSC are proposed and empirical equations for determining direct tensile strength, peak strain, and elastic modulus at different temperatures are provided Finite element method is applied to simulate the direct tensile tests using the proposed complete stress-strain relationship. Predictions based on the finite element simulations are in good agreement with the test results.