镍粉复合水泥基材料的压敏性研究

Piezoresistivity of Cement-Based Materials with Nickel Powder

为探讨镍粉复合水泥基材料的压敏性,首先研究了一次加载至破坏时不同掺量镍粉复合水泥基材料的电阻率变化规律,然后通过在弹性阶段的加载考察掺量为25%(体积分数,下同)的镍粉复合水泥基材料压敏性的重现性,最后研究了加载速率和试件偏压对掺量25%的镍粉复合水泥基材料压敏性的影响。结果表明:掺量15%和20%的镍粉复合水泥基材料不具有压敏性。掺量25%的镍粉复合水泥基材料一次加载至破坏,电阻率变化率最大可达40%,弹性阶段电阻率变化率可达35%以上,具有良好的压敏性;且其压敏性基本不受加载速率和试件偏压的影响。镍粉是制备具有高感知灵敏度的压敏水泥基材料的一种有效功能组分。

In order to explore the piezoresistivity of cement-based materials with nickel powder, the variation regularity of electrical resistivity of cement-based materials with nickel powder under single compressive loading is firstly studied in this paper, and then the reproducibility of piezoresistivity of these cement-based materials within elastic regime is investigated. The influence of loading speed and eccentric loading on the piezoresistivity of cement-based materials with nickel powder is discussed finally. The research results show that cement-based materials with vo115% and vol 20% nickel powder do not present piezoresistivity. The fractional change in electrical resistivity of cement-based materials with vol 25% nickel powder goes up to 40% and 35% under single compressive loading and within elastic regime respectively, which indicates these materials possess favorable piezoresistivity. And the piezoresistivity of cement-based materials with vo125% nickel powder is almost free form the influence of loading speed and eccentric loading. These findings suggest that the nickel powder is an effective component for manufacturing piezoresistive cement-based materials with high sensitivity.