Experimental Research on Heat Swelling Power of Sandstone and Limestone

The change laws of heat swelling power and porosity of sandstone and limestone were researched at different temperatures using a heat swelling power experimental system and a porosity test apparatus.The results show that the swelling power of rocks increases with the heating time,and finally tends to its maximum.At the same heating temperature the swelling power of sandstone is larger than that of limestone and the largest swelling power of sandstone is nine times more than that of limestone.Because the change speed of sandstone swelling power in response to temperature is slower than that of limestone,the ratio of heat swelling power of sandstone at the end of constant temperature to at the end of temperature rise is larger than that of limestone.The variousness law of porosity with the temperature is almost as same as that of the swelling power.The starting temperature of porosity increasing rapidly is lower than that of swelling power increasing promptly.