碳纤维–碱激发砂浆自感知性能

Self-Sensing Property of Carbon Fiber–Alkali Activated Mortar

采用短切碳纤维(CF)作为导电材料制备碱激发矿渣/粉煤灰复合导电砂浆,研究了碳纤维掺量、应力加载幅值和加载速率对碳纤维–碱激发导电砂浆导电性能、力学性能与自感知性能的影响。结果表明:碳纤维体积分数为0.2%时,碱激发导电砂浆达到渗流阈值,形成导电通路,且在不同加载速率和应力幅值作用下均表现出稳定的自感知性能和较高的灵敏度。当应力幅值为12.0 MPa、加载速率为2.0 kN/s时,自感知性能最优,应变灵敏度可达175.0,比碳纤维–水泥砂浆高1个数量级。

Chopped carbon fiber(CF)was used as a conductive material to prepare alkali-activated slag/fly ash conductive mortar.The effects of carbon fiber content,stress loading amplitude and loading rate on the conductivity,mechanical properties and self-sensing properties of carbon fiber–alkali-activated conductive mortar were investigated.The results show that the alkali-activated conductive mortar reaches the percolation threshold and forms a conductive path when the volume fraction of carbon fiber is 0.2%.The mixture has a stable self-sensing performance with a high gauge factor at different loading rates and stress amplitudes.The self-sensing performance of alkali-activated slag/fly ash is the optimum with a gauge factor of 175,which is one order of magnitude greater than that of carbon fiber–cement mortar,when the stress amplitude is 12 MPa and the loading rate is 2.0 kN/s.