【摘要】 对常温、200℃、400℃、600℃和800℃后不同纳米碳酸钙(NC)掺量的混凝土进行了抗压试验,观察了混凝土试块不同温度后表面颜色的变化及裂缝开展情况,分析了混凝土的质量损失、抗压强度随温度的变化规律,并采用SEM电镜对高温后纳米混凝土的微观结构进行了观测。结果表明:温度越高,混凝土的外观特征变化越明显,质量损失率及抗压强度损失均随温度升高而增加。适量NC的添加可以改善混凝土的内部结构,提高混凝土的抗压强度,混凝土中NC的最佳掺量为0.5%。通过数据分析,建立了NC05(NC掺量0.5%)混凝土残余抗压强度比与温度关系的表达式,可为进一步研究NC混凝土高温后的性能提供参考。更多还原

【Abstract】 The compressive tests of concrete with different content of nano-CaCO₃（ NC） at room temperature,200 ℃,400 ℃,600 ℃ and 800 ℃ were carried out. The change of color and crack development of concrete after different temperatures were observed. The change law of mass loss and compressive strength of concrete with temperature were analyzed. The microstructure of nano-concrete after high temperature was scanned by SEM. The results show that the higher the temperature,the more obvious the change of concrete appearance characteristics. The mass loss rate and compressive strength loss increase with the increase of temperature. Adding proper amount of NC can improve the internal structure and the compressive strength of concrete. The optimum content of NC in concrete is 0. 5%.Based on the data analysis, the relationship between the residual compressive strength ratio and temperature of NC05 concrete is established. It provides a reference for further study on the properties of NC concrete after high temperature.更多还原