Temperature dependence of thermal induced mesocracks around limestone aggregate in normal concrete

This paper presents the results of thermal expansion measurements of mortar and limestone aggregate and thermal induced mesocracks around limestone aggregate in normal concrete exposed to high temperature, up to 800°C. The former was measured by a fused silica Workhorse Dilatometer. The later was observed by the viewfinder of Polarizing Optical Microscope. The results showed that the difference in coefficient of thermal expansion between mortar and limestone exhibited the temperature dependence. Thermal induced tensile stress around limestone aggregate first took place, following the hydrostatic compression under higher temperature. During the whole heating process, the tangential, radical and linkage mesocracks in concrete gradually initiated and propagated for the response of thermal induced stress around limestone aggregate. Copyright © 2009 John Wiley & Sons, Ltd.