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

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.