超低温作用后高韧性水泥基材料抗碳化性能研究

Study on carbonation resistance of high toughness cementitious composites under ultralow temperature environment

对高韧性水泥基复合材料进行超低温作用后的碳化试验,研究了温度、纤维掺量、碳化时间对高韧性水泥基材料的抗碳化性能影响。通过对不同碳化龄期、温度、纤维体积掺量下的碳化深度与常温下碳化深度对比分析深冷环境下碳化损伤。结果表明:在-50~20℃范围内,低温对高韧性纤维水泥基材料的损伤与常温相当;在-196^-100℃范围内超低温环境会对水泥基材料的碳化性能有显著影响,温度越低对混凝土碳化性能影响越明显;掺入PVA纤维能提高低温下水泥基材料的碳化性能,但纤维掺量应控制在1.0%~1.5%,大于1.5%时超低温环境会加剧水泥基材料的碳化。

The carbonation test of high toughness cementitious composites under ultra-low temperature was carried out to study the influence of temperature,fiber content and carbonation time on the carbonation resistance of high toughness cementitious Composites.The carbonation damage in cryogenic environment was obtained by regression analysis of carbonation depth under different carbonation age,temperature and fiber volume fraction compared with carbonation depth under normal temperature.The results show that the damage of low temperature to high toughness cementitious composites is equivalent to normal temperature in the range of-50~20℃.When the temperature is in the range of-196℃to-100℃,the ultra-low temperature environment will have a severe impact on the carbonation performance of high toughness cementitious composites,and the lower the temperature,the better the carbonation performance of concrete will be.PVA fiber can improve the carbonization performance of high toughness cementitious composites after low temperature,but the fiber contents should be controlled between 1.0%~1.5%,and the carbonization will be intensified if it exceeds 1.5%.