The electrical conductivity and piezoresistivity of carbon fiber graphite cement-matrix composites（CFGCC） with carbon fiber content（1% by the weight of cement）,graphite powder contents （0%-50% by the weight of ce...The electrical conductivity and piezoresistivity of carbon fiber graphite cement-matrix composites（CFGCC） with carbon fiber content（1% by the weight of cement）,graphite powder contents （0%-50% by the weight of cement） and CCCW（cementitious capillary crystalline waterproofing materials,4% by the weight of cement） were studied.The experimental results showed that the relationship between the resistivity of CFGCC and the concentration of graphite powders had typical features of percolation phenomena.The percolation threshold was about 20%.A clear piezoresistive effect was observed in CFGCC with 1wt% of carbon fibers,20wt% or 30wt% of graphite powders under uniaxial compressive tests,indicating that this type of smart composites was a promising candidate for strain sensing.The measured gage factor （defined as the fractional change in resistance per unit strain） of CFGCC with graphite content of 20wt% and 30wt% were 37 and 22,respectively.With the addition of CCCW,the mechanical properties of CFGCC were improved,which benefited CFGCC piezoresistivity of stability.展开更多
为选取用于河北武强220 k V变电站屋面的最优防水方案,设计了6个不同防水方案的试件进行试验研究。在试件中预埋应变计用于测试防水卷材和混凝土板的温度应变,得到应变随温度变化的规律。试验结果表明,从下至上采用"单组分聚氨酯...为选取用于河北武强220 k V变电站屋面的最优防水方案,设计了6个不同防水方案的试件进行试验研究。在试件中预埋应变计用于测试防水卷材和混凝土板的温度应变,得到应变随温度变化的规律。试验结果表明,从下至上采用"单组分聚氨酯防水涂料层+聚合物防水砂浆层+热塑性聚烯烃高分子防水卷材"的组合形式,应变协调性好,试件的防水性能最好。展开更多
基金Funded by the National Natural Science Foundation of China(No.50878170 and No. 10672128)
文摘The electrical conductivity and piezoresistivity of carbon fiber graphite cement-matrix composites（CFGCC） with carbon fiber content（1% by the weight of cement）,graphite powder contents （0%-50% by the weight of cement） and CCCW（cementitious capillary crystalline waterproofing materials,4% by the weight of cement） were studied.The experimental results showed that the relationship between the resistivity of CFGCC and the concentration of graphite powders had typical features of percolation phenomena.The percolation threshold was about 20%.A clear piezoresistive effect was observed in CFGCC with 1wt% of carbon fibers,20wt% or 30wt% of graphite powders under uniaxial compressive tests,indicating that this type of smart composites was a promising candidate for strain sensing.The measured gage factor （defined as the fractional change in resistance per unit strain） of CFGCC with graphite content of 20wt% and 30wt% were 37 and 22,respectively.With the addition of CCCW,the mechanical properties of CFGCC were improved,which benefited CFGCC piezoresistivity of stability.
文摘为选取用于河北武强220 k V变电站屋面的最优防水方案,设计了6个不同防水方案的试件进行试验研究。在试件中预埋应变计用于测试防水卷材和混凝土板的温度应变,得到应变随温度变化的规律。试验结果表明,从下至上采用"单组分聚氨酯防水涂料层+聚合物防水砂浆层+热塑性聚烯烃高分子防水卷材"的组合形式,应变协调性好,试件的防水性能最好。
