硫酸钙晶须对混凝土渗透性影响的试验研究

Experimental research on the influence of calcium sulfate whisker on the permeability of concrete

为研究硫酸钙晶须对混凝土渗透性的影响,通过压差稳定法和电通量法分别测试了硫酸钙晶须混凝土的气体渗透系数及氯离子扩散系数,同时采用压汞法测定其微观孔结构参数。试验结果与分析表明:硫酸钙晶须能降低混凝土的渗透性,且相对氯离子扩散性,对降低其气体渗透性的影响更加明显;当硫酸钙晶须掺量为0.5%的水泥质量时,混凝土的气体渗透系数及氯离子扩散系数最小。掺加硫酸钙晶须可降低混凝土的孔隙率,掺量为0.5%水泥质量时,混凝土的孔隙率最低;硫酸钙晶须的掺入降低了混凝土毛细孔的孔径占比,减少了毛细孔压力和毛细孔渗透力,从而降低了混凝土的渗透性。

Calcium sulfate whisker was incorporated into concrete to research its influence on the permeability of concrete.The gas permeability coefficient and effective chloride diffusion coefficient of concrete were measured by Cembureau method and ASTM C1202 test respectively.In addition,the pore structure of concrete was determined by mercury intrusion porosimetry(MIP).Results show that calcium sulfate whiskers can reduce the permeability of concrete,and the relative effective chloride diffusion coefficient,gas permeability coefficient decreased more pronounced.When added with whisker by weight of 0.5%cement content,the concrete had the better impermeability.From the micro-pore structure parameters,it can be seen that the addition of whiskers reduces the porosity of the concrete.When the whisker content is 0.5%,the porosity is the lowest.At the same time,the addition of whiskers reduces the proportion of pore within range of 10~100 nm and reduces capillary pressure and capillary permeability,thus improving the permeability of concrete.