Performance Evaluation of Self-Compacting Glass Fiber Concrete Incorporating Silica Fume at Elevated Temperatures

In this work, the properties of self-compacting concrete (SCC) and SCC containing 0.5 and 1% glass fibers (with lengths of 6 and 13 mm) were experimentally investigated, as well as their performance at high temperatures. With a heating rate of 5 °C/min, high-temperature experiments were conducted at 200, 400, 600, and 800 °C to examine mass loss, spalling, and the remaining mechanical properties of SCC with and without glass fibers. According to the results of the flowability and passing ability tests, adding glass fibers does not affect how workable and self-compacting SCCs were. These findings also demonstrated that the mechanical properties of samples with and without glass fibers rose up to 200 °C but then decreased at 400 °C, whereas the mixture containing 0.5% glass fibers of a length of 13 mm displayed better mechanical properties. Both SCC samples with and without glass fibers remained intact at 200 °C. Some SCC samples displayed some corner and edge spalling when the temperature reached about 400 °C. Above 400 °C, a significant number of microcracks started to form. SCC samples quickly spalled and were completely destroyed between 600 and 800 °C. According to the results, glass fibers cannot stop SCC from spalling during a fire. Between 200 and 400 °C, there was no discernible mass loss. At 600 °C, mass loss starts to accelerate quickly, and it increased more than ten times beyond 200 °C. The ultrasonic pulse velocity (UPV) of SCC samples with glass fibers increased between room temperature and 200 °C, and the mixture containing 0.5% glass fibers of a length of 13 mm showed a somewhat higher UPV than other SCC mixtures until it started to decline at about 400 °C.