Physical–Mechanical Behavior of High-Performance Concrete and Ordinary Concrete with Portland Cement Mixtures After Exposure to Selected Durability Tests Including High Thermal Stress

This study examines the verification of the mechanical properties of ordinary concrete with Portland cement (OPC) and high-performance concretes (HPCs) after exposure to the effects of varying temperatures, in addition to durability tests as part of the experimental testing. Particular emphasis is placed on the comparison between OPC and HPC. Before describing the behavior of concrete under the influence of heat and the difference between ordinary and high-performance concrete, the microstructures of both hardened mixtures were monitored, and the chemical compounds of the used Portland cement and silica fume were analyzed using a scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). For the experiments, compressive strength and flexural strength tests were performed before and after stressing at elevated temperatures. Furthermore, the experiments included the following: a study of concrete color changes under the influence of elevated temperatures, the use of the ultrasonic pulse method, the determination of resistance to water and chemical de-icing agents, and an examination of the frost resistance of concrete. This study considers the differences between the two concretes—OPC and HPC—especially in terms of their mechanical properties, as well as their durability and resistance to chemicals. This research contributes to the understanding of the properties of the two types of concrete; subsequently, it can help in the selection of concrete for specific applications.