Experimental Study on Hydraulic and Macro-Mechanical Property of a Mortar under Heating and Cooling Treatment

A research program was carried out to investigate the effect of heating and cooling treatment upon hydraulic property and macro-mechanical property of cement based material. Those treatments were performed on cylindrical mortar specimens (water to cement ratio of 0.5), subjected to 5, 10, 15 heating-cooling cycle times and three levels of maximum heating temperatures of 105 degrees C, 145 degrees C and 200 degrees C. The hydraulic property tests were performed on a gas permeability and porosity test system. The initial permeability and porosity value of the material were measuring before the heating and cooling treatment under slightly confine (3MPa) and show the material has a good homogeneity. The damage of mortar due to the effect of heating and cooling treatment were evaluated the variation of permeability, porosity and macro-mechanical parameters by compare before and after heating and cooling treatment. Significant changes in the macro-mechanical property and hydraulic property before and after heating and cooling treatment in mortar were observed. The compressive strength and elastic modulus gradually decrease with the increase of maximum heating temperature and the number of heating cycles, while the porosity and permeability increases gradually.