碳纳米管对高强混凝土收缩性能的试验研究及其模型修正

Experimental Study and Model Modification of Carbon Nanotubes on Shrinkage Performance of High-Strength Concrete

碳纳米管(CNT)对高强混凝土收缩的影响直接关系到结构长期性能。制作CNT掺量分别为0%、0.1%、0.3%和0.5%的100 mm×100 mm×515 mm的C60混凝土棱柱体试件,在试验室条件下进行收缩试验,研究了CNT对高强混凝土收缩的影响。根据试验结果评估了目前常用的两种相关规范模型对高强混凝土收缩的适用性,并引入CNT影响系数以综合反映CNT掺量对高强混凝土收缩的影响,根据试验结果和现有研究成果提出了其修正模型。分析结果表明,ACI收缩预测模型与混凝土试件实测结果较为吻合,验证结论亦说明所引入的CNT影响系数可应用于掺CNT高强混凝土的收缩预测。

The effect of carbon nanotubes(CNT)on shrinkage of high-strength concrete is directly related to the long-term performance of the structure.The C60 concrete prismatic specimens with CNT content of 0%,0.1%,0.3%and 0.5%were prepared,and the shrinkage tests were carried out under laboratory conditions to study the effect of CNT on the shrinkage of high-strength concrete.According to the test results,the applicability of two commonly used specification models to the shrinkage of high-strength concrete is evaluated,and the influence coefficient of CNT is introduced to comprehensively reflect the influence of CNT content on the shrinkage of high-strength concrete.The analysis results show that the ACI shrinkage prediction model is in good agreement with the measured results of concrete specimens,and the verification results also show that the CNT influence coefficient introduced can be applied to the shrinkage prediction of high-strength concrete doped with CNT.