Piezoresistivity of Carbon Fiber Graphite Cement-based Composites with CCCW

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.

凹土对渗透结晶型防水砂浆性能影响的研究

通过介绍煅烧850℃原矿凹土对渗透结晶防水砂浆的性能影响,研究了掺0%、2%、4%、6%、8%的850℃煅烧凹土与渗透结晶防水剂复合后对防水砂浆的保水性,28d抗压强度、黏结强度以及抗渗压力的影响.试验结果表明,煅烧凹土对防水砂浆的抗渗性有显著提高,且以850℃煅烧凹土替代部分渗透结晶防水剂可以大大降低防水砂浆的成本.

煅烧凹土对防水砂浆性能影响的研究

研究了850℃煅烧凹土与防水剂复合使用后对防水砂浆的性能影响,包括掺0%、2%、4%、6%、8%的煅烧凹土分别与渗透结晶型防水剂和微晶防水剂复合后对防水砂浆保水性、抗压强度、粘结强度以及抗渗压力的影响。试验结果表明,煅烧凹土对防水砂浆的抗渗性都有显著提高;煅烧凹土对渗透结晶型防水剂的改善效果更为显著。

矿渣粉对水泥基渗透结晶型防水砂浆性能的影响研究

以矿渣粉为掺合料制备水泥基渗透结晶型防水砂浆,研究不同掺量的矿渣粉对水泥基渗透结晶型防水砂浆抗压强度、劈裂抗拉强度以及抗渗压力的影响规律,为矿渣粉在水泥基渗透结晶防水材料中的应用提供参考。结果表明,水泥基渗透结晶型防水砂浆抗压强度、劈裂抗拉强度均随矿渣粉掺量的增加先增大后减小;水泥基渗透结晶型防水砂浆的第2次抗渗压力要高于第1次抗渗压力。

防水剂、膨胀剂及引气剂对砂浆防水性能的影响研究

研究了渗透结晶型防水剂、UEA膨胀剂、十二烷基苯磺酸钠引气剂对砂浆防水性能的影响,重点考察了三种外加剂掺量对砂浆水灰比、保水率、含气量、抗压强度和抗渗强度的影响规律,确定了各自的最佳掺量,并分析了三种外加剂的成本。指出,实际工程中要根据具体情况和要求,有选择性地选用外加剂或外加剂组合。