Using high strength concrete, instead of the conventional one, has been increasingly growing in popularity over recent years. However, the safety concerns associated with their fire performance, resulting from higher density, can call its advantages into question. As opposed to data circumscribed on compressive and tensile strength, rare are studies that have been focused on other aspects of high strength concrete, like shear strength or durability properties, in hot conditions. To conduct a thorough investigation, an experimental program embodying mechanical, durability, and microstructural aspects was performed on normal and high strength concrete in nine specific temperatures (ranging from 100 °C to 800 °C). Furthermore, a sort of relations to estimate the reduction values of mechanical properties were proposed, discussed, and compared with previous studies and standards. Although high strength concrete samples enjoyed higher capacity than normal specimens in all temperatures, their reduction rate intensified when the temperature exceeded 400 °C. The initial values for compressive, tensile, and shear strength of HSC, which were about 91.7, 5.6, and 9.5 MPa at room temperature, reduced to 28.4, 0.87, and 8.97 MPa at 800 °C, respectively. Furthermore, when temperature surpassed 400 °C, decay in high strength concrete microstructure manifested itself at durability (more than 90% growth in water absorption) and SEM images (increase in porosity) conspicuously.

近年来，使用高强度混凝土代替传统混凝土已经越来越受欢迎。但是，由于密度较高而引起的与防火性能相关的安全隐患可能会质疑其优势。与关于抗压强度和抗拉强度的数据相反，很少有研究集中在高温条件下高强度混凝土的其他方面，例如剪切强度或耐久性能。为了进行彻底的研究，在正常和高强度混凝土上在九个特定温度（范围为100°C至800°C）上执行了包含机械，耐久性和微观结构方面的实验程序。此外，提出了一种关系来估算机械性能的降低值，并与以前的研究和标准进行比较。尽管高强度混凝土样品在所有温度下均具有比普通样品更高的承载能力，但当温度超过400°C时，其还原速率会加快。HSC的抗压强度，拉伸强度和剪切强度的初始值在室温下分别约为91.7、5.6和9.5 MPa，在800°C下分别降低至28.4、0.87和8.97 MPa。此外，当温度超过400°C时，高强度混凝土的微观结构会在耐久性（吸水率增长90％以上）和SEM图像（孔隙率增加）上表现出来。HSC的抗压强度，拉伸强度和剪切强度的初始值在室温下分别约为91.7、5.6和9.5 MPa，在800°C下分别降低至28.4、0.87和8.97 MPa。此外，当温度超过400°C时，高强度混凝土的微观结构会在耐久性（吸水率增长90％以上）和SEM图像（孔隙率增加）上表现出来。HSC的抗压强度，拉伸强度和剪切强度的初始值在室温下分别约为91.7、5.6和9.5 MPa，在800°C下分别降低至28.4、0.87和8.97 MPa。此外，当温度超过400°C时，高强度混凝土的微观结构会在耐久性（吸水率增长90％以上）和SEM图像（孔隙率增加）上表现出来。