A Thoroughgoing Study on Engineering Properties of High Strength Concrete at Elevated Temperatures
A Thoroughgoing Study on Engineering Properties of High Strength Concrete at Elevated Temperatures
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DOI：
10.1007/s10694-021-01093-2
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发表时间：
2021-02
期刊：
影响因子：
3.4
通讯作者：
R. Izadifard;A. Khalighi;Mehrdad Abdi Moghadam;Hossein Balouei Pirnaeimi
中科院分区：
文献类型：
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作者：
R. Izadifard;A. Khalighi;Mehrdad Abdi Moghadam;Hossein Balouei Pirnaeimi
近年来，使用高强度混凝土代替传统混凝土越来越受欢迎。然而，由于密度较高，与其防火性能相关的安全问题可能会使其优势受到质疑。与压缩和拉伸强度的数据相反，很少有研究关注高强度混凝土的其他方面，例如热条件下的剪切强度或耐久性能。为了进行彻底的研究，在九个特定温度（范围从 100°C 到 800°C）下对普通和高强度混凝土进行了体现机械、耐久性和微观结构方面的实验计划。此外，还提出、讨论了一种估计机械性能折减值的关系式，并与以前的研究和标准进行了比较。尽管高强度混凝土样品在所有温度下都比普通样品具有更高的承载力，但当温度超过 400 °C 时，其减少率会加剧。 HSC 的压缩强度、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 时分别降至 28.4、0.87 和 8.97 MPa。此外，当温度超过 400 °C 时，高强度混凝土微观结构的衰退在耐久性（吸水率增长超过 90%）和 SEM 图像（孔隙率增加）方面表现得非常明显。
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.