基于孔溶液性质的减缩剂减缩机理研究

摘要

The influence of temperature and alkalinity on shrinkage reducing performance of shrinkage reducing agent(SRA)was investigated based on the Laplace equation.The contacting property between pore solution and capillary pore wall of cement paste was studied and the action mechanism of shrinkage reduction based on γcos θ was analyzed.According to the experiment results,the reduction ability of SRA to reduce surface tension is enhanced by the increase in temperature and alkalinity; the wet condition of pore solution in cement paste is changed by SRA; the shrinkage development trend of cement paste can be accurately predicted by the shrinkage reducing mechanism based on contacting property and surface tension.%在进行减缩剂减缩机理的研究中,以Laplace方程为理论依据,分析了温度、碱度对减缩剂降低孔溶液表面张力的影响,评价了掺减缩剂孔溶液与水泥石毛细孔壁的接触性质,并对以γcos θ表征的减缩机理有效性进行了评价.结果表明:温度和碱度的提高增强了减缩剂降低溶液表面张力的能力;减缩剂将孔溶液与水泥石的接触性质由润湿转变为半润湿状态;建立的以γcos θ表征的减缩机理能较准确地预测水泥石收缩的发展趋势.