不同冷却方式下高温混凝土性能研究

关键字：不同,冷却方式,高温,混凝土,性能,研究

（吉林大学 建设工程学院，吉林 长春  130026）

    摘要：对混凝土立方体试件进行高温烧结，分析了试件外观裂缝的产生和发展，质量损失率等宏观变化。通过对高温混凝土试件在不同冷却方式下的抗压强度、劈拉强度进行力学性能试验，对比出不同冷却方式下高温混凝土的抗压强度及劈拉强度的差异和变化趋势，解释了高温混凝土强度变化的原因，拟合出对应的强度变化曲线。结果表明：高温混凝土经自然冷却后出现强度反弹迹象，在400 ℃达到峰值39.9 MPa；喷淋冷却使得混凝土抗压强度在500 ℃达到峰值36.7 MPa，在500 ℃后，强度高于自然冷却后的混凝土强度。劈拉强度随着温度升高持续降低，800 ℃时强度损失达到80%。该研究可为受高温后的混凝土结构的设计、分析提供理论依据。
    关键词：混凝土；高温；冷却方式；力学性能；宏观变化
    中图分类号：TU528.01        文献标识码：A        文章编号：1001-702X（2017）08-0119-04

Study on properties of high temperature concrete under different cooling methods
QU Haikun，ZHOU Lincong，WANG Li，GUO Kai，WANG Guoxiang，WANG Xinyu
（College of Construction Engineering，Jilin University，Changchun 130026，China）

    Abstract：Through the high temperature sintering process of concrete specimens，analyzed the emergence and development of the appearance of cracks，the mass loss rate of the macro changes. Mechanical property test was done for the compressive and splitting tensile strength under different cooling methods of high temperature concrete specimens，compared the difference and change tendency of compressive and splitting tensile strength under different cooling methods，explained the reasons for the change of the strength of high temperature concrete，fitted the corresponding intensity change curve. The results show that the strength of high temperature concrete rebounds after natural cooling，reaches a peak of 39.9 MPa at 400 ℃. Spraying cooling makes the compressive strength of concrete reach a peak of 36.7 MPa at 500 ℃，after 500 ℃，the strength is higher than that after natural cooling. The tensile strength decreases with the increase of temperature，and the strength loss reaches 80% at 800 ℃. This study provides the theoretical basis for the design and analysis of the concrete structure after high temperature.
    Key words：concrete，high temperature，cooling method，mechanical property，macro change