Laboratory Study of Weight Loss and Ultrasonic Wave Propagation Velocity in Conventional Concrete Under High Temperature, Along with Validation by SEM and XRD Analysis

In this laboratory study, a mixed concrete design containing Portland cement type ۲ with a grade of ۵۰۰ kg/m۳ was made. Weight loss and ultrasonic pulse velocity (UPV) tests were performed on concrete samples at a curing age of ۹۰ days at room temperature (۲۱ ℃) and under a temperature of ۶۰۰ ℃. In order to further investigate and verify the results, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were performed on concrete samples at a curing age of ۹۰ days. The results of the tests in this study were evaluated together and compared and analysed with the results of other researchers. Applying high heat to concrete samples caused a decrease in results. In this regard, in the weight loss test of concrete samples, the weight of the concrete sample decreased from ۲۳۷۸ to ۲۲۲۵ grams, which was a decrease of ۷۲.۶%, and in the UPV test, the speed of ultrasonic waves decreased from ۶۱۷۹ to ۳۴۱۱ m/s, which was a decrease of ۷۹.۴۴%. At the end of this study, the results of SEM and XRD analysis at room temperature and under high temperature, while coordinating with each other, overlapped with the results of the weight loss test and the ultrasonic wave velocity test in concrete samples.In this laboratory study, a mixed concrete design containing Portland cement type ۲ with a grade of ۵۰۰ kg/m۳ was made. Weight loss and ultrasonic pulse velocity (UPV) tests were performed on concrete samples at a curing age of ۹۰ days at room temperature (۲۱ ℃) and under a temperature of ۶۰۰ ℃. In order to further investigate and verify the results, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were performed on concrete samples at a curing age of ۹۰ days. The results of the tests in this study were evaluated together and compared and analysed with the results of other researchers. Applying high heat to concrete samples caused a decrease in results. In this regard, in the weight loss test of concrete samples, the weight of the concrete sample decreased from ۲۳۷۸ to ۲۲۲۵ grams, which was a decrease of ۷۲.۶%, and in the UPV test, the speed of ultrasonic waves decreased from ۶۱۷۹ to ۳۴۱۱ m/s, which was a decrease of ۷۹.۴۴%. At the end of this study, the results of SEM and XRD analysis at room temperature and under high temperature, while coordinating with each other, overlapped with the results of the weight loss test and the ultrasonic wave velocity test in concrete samples.

کلیدواژه ها:

Ultrasonic Pulse Velocity (UPV) ، Temperature ، Scanning Electron Microscopy (SEM) ، X-ray Diffraction Spectroscopy (XRD) ، Conventional Concrete