加载条件对纳米石墨烯片水泥基复合材料压敏性能的影响

研究不同纳米石墨烯片(GNPs)掺量下加载幅值(15 MPa、20 MPa、25 MPa)和加载速率(100 N/s、300 N/s、500 N/s)对纳米石墨烯片水泥基复合材料(GNPs/CC)压敏性能的影响。试验结果表明:在GNPs掺量低于0.25%(质量分数,下同)时,GNPs/CC的压敏性能与空白组相近;在掺量达到0.3%时,GNPs/CC的电阻变化率最大,且重复性最好。在GNPs掺量为0.3%的情况下,GNPs/CC的电阻变化率与应变随加载幅值的增加而增大,在加载幅值不大于20 MPa时,GNPs/CC的电阻变化率与应变的增加幅度相近,材料的灵敏因子变化较小;在加载幅值达到25 MPa时,由于电阻变化率的增加幅度大于应变的增加幅度,材料的灵敏因子出现了较明显的增加。而加载速率在纳米石墨烯片掺量为0.3%时,对材料的压敏性能无明显影响。

Influences of Loading Conditions on Piezoresistive Properties of Graphene Nanoplatelets Reinforced Cement-Based Composites

In this paper, the effects of loading amplitude (15 MPa, 20 MPa, 25 MPa) and loading rate (100 N/s, 300 N/s, 500 N/s) on the piezoresistive properties of graphene nanoplatelets reinforced cement-based composites (GNPs/CC) were studied under different dosages of graphene nanoplatelets (GNPs). The experimental results show that the piezoresistive properties of graphene nanoplatelets reinforced cement-based composites are similar to that of the blank group when the dosage of graphene nanoplatelets is less than 0.25% (mass fraction, the same below). When the dosage reaches 0.3%, the composite has the highest and the most repeatable resistance variation. When the dosage of graphene nanoplatelets is 0.3%, the resistance variation and strain of the composite rise with the increase of the loading amplitude. When the loading amplitude is no more than 20 MPa, the increase of the resistance variation is similar to that of the strain, the gauge factor of the composite changes little. When the loading amplitude reaches 25 MPa, the increase of the resistance variation is larger than that of the strain. And the gauge factor of the composite increases largely. In addition, the loading rate has no significant effect on the piezoresistive properties of the composite when the dosage of graphene nanoplatelets is 0.3%.