Effect of Thermal and Freeze-thaw Stress on the Mechanical Properties of Porous Limestone

This paper focuses on the effect of high temperature on the mechanical properties of a porous limestone that is widely used as dimension stone in Hungary. The changes in physical properties of 3 types of porous limestone were analyzed at 22 °C, 300 °C and 600 °C, respectively. The limestone specimens were also subjected to freeze-thaw cycles to assess the other extrinsic factor that influences the behavior. Parameters such as material density, bulk density, ultrasonic pulse velocity and tensile strength were measured and compared in different test conditions. The tests results indicate that fabric differences significantly influences the durability of tested limestones. Bioclastic grainstone is more frost resistant that ooidal grainstone or bioclastic packstone, but heating seems to reduce the pulse velocity and tensile strength of all tested limestone. It is suggested that cyclic freezing-thawing reduces the strength depending on the micro-fabric, while heating to 600 °C and the reduction of strength is less controlled by the fabric of the porous limestone.