Impact of exposed high temperature on hybrid self-compacted concrete

Document Type : High quality original papers

Authors

1 College of Engineering, Baghdad University, Iraq.

2 College of Engineering, Tikrit University, Iraq.

Abstract

This paper presents an experimental study on the performance of self-compacted concrete (SCC) subjected to high temperature. Two SCC mixtures were tested. For each test, the specimens were heated at a rate of 1 °C/min up to different temperatures (150, 300, 450 and 600 °C). In order to ensure a uniform temperature throughout the specimen, the temperature was held constant at the target temperature for one hour before cooling. It has noted an important increase in compressive strength of about 11.22 % between 150 and 300 °C for RSCC job mix specimens at an age of 60 days, and 6.22 % for HSCC job mix specimens for the same age, while at an age of 90 Days RSCC job mix specimens showed an increase of about 3.2% compared to 3.53% for HSCC job mix specimens, For HSCC job mix specimens, It has noted that for RSCC job mix specimens, the compressive strength for temperature rate of 450 °C as in table 15 decreased to 31.01% and 41.25% at an ages of 60 and 90 days respectively compared to their relatives in table 14 not exposed to high temperature, and 41.32% and 48.39% for temperature rate of 600 °C at an ages of 60 and 90 days respectively. For HSCC job mix specimens, the compressive strength for temperature rates of 450 °C decreased to 37.69% and 40.49% at an ages of 60 and 90 days respectively compared to their relatives not exposed to high temperature, and 47.55% and 48.26% for temperature rate of 600 °C at an ages of 60 and 90 days respectively, and this is due mainly to alteration of the porous network (Departure of bond water and decomposition of hydrates and to the microcracking).

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