多壁碳纳米管水泥基复合材料的压敏性能研究

采用聚羧酸系减水剂分散多壁碳纳米管（ MWCNTs ），利用四电极法研究了 MWCNTs 掺量对28 d 龄期MWCNTs水泥基复合材料导电特性和在循环荷载作用下压敏性能的影响以及不同最大加载力和加载速率下材料压敏性能的变化。研究表明：随 MWCNTs 掺量的增加，复合材料的电阻率逐渐降低，极化时间逐渐减少。当MWCNTs的掺量在0．06wt％～0．3wt％范围时，复合材料电阻率的变化最大，在循环荷载作用下也表现出良好的压敏性。当加载至试块破坏的情况下，最大电阻变化率可达到70％。随着加载力和加载速率的增加，电阻率的变化率均逐渐变大。本项研究对于实现混凝土材料的智能化以及工程结构检测的实时化具有重要意义。

Stress-sensing Performance of MWCNTs Cement Composites

Polycarboxylate superplasticizer was used to disperse multi-walled carbon nanotubes ( MWCNTs) and four electrode method was used to study the influence of MWCNTs on the electrical resistivity and stress-sensing properties of multi-walled carbon nanotube-based cement composites (MWNTs/CC).The effect of several variables on the stress-sensing function was studied, e.g. MWCNTs content , maximum stress applied and loading rate .The results show that with the increase of the dosage of MWCNTs , the electrical resistivity of composites decreases gradually , and the polarization time reduces gradually .When the dosage of MWCNTs between 0.06wt% to 0.3wt%, the MWNT/CC exhibit excellent stress-sensing property and the optimum dosage of MWCNTs is 0.1wt%.When the samples were progressively loaded until failure , the maximum fractional change of electrical resistance is up to 70%.With the increase of maximum loading stress and loading rate , the ratio of electrical resistivity change increases gradually .