纳米碳纤维混凝土在劈裂及抗弯试验中的压敏特性研究

为促进智能混凝土材料在桥梁上的应用,通过劈裂及抗弯试验研究纳米碳纤维混凝土的压敏特性。试验结果显示:纳米碳纤维混凝土的电阻会随压应力的增大而减小,随拉应力的增大而增大,电阻变化率与拉、压应力之间呈良好的线性规律;适当掺量且分散良好的纳米碳纤维可以使混凝土复合材料获得良好的压敏特性,成为自身具有损伤评估和应变监测功能的传感器。基于纳米碳纤维混凝土的良好压敏特性,将其作为具有应变监测功能的智能混凝土材料应用于桥梁结构中非常可行。

Piezoresistive Behavior of Carbon Nano-Fiber Concrete in Split and Bending Tests

In order to boost the application of the intelligent concrete materials in bridge engineering,the piezoresistive behavior of the carbon nano-fiber(CNF) concrete is experimentally studied through split and bending tests.The results of the study show that the electric resistance of the CNF concrete decreases as the compressive stress increases,and increases as the tensile stress rises,and the change rate of electric resistance and the variation of compressive and tensile stresses follow good linear law.The concrete composite material added with proper amount well dispersed CNF shows good piezoresistive behavior and becomes a sensor with damage assessment and strain monitoring functions itself.Due to the good piezoresistive behavior,CNF concrete is possible to be used as the intelligent concrete material with strain monitoring function in bridge structures.