Thermal Conductivity Measurements of Weathered Limestone

Thermal properties of geological materials are required for analysis and design of energy geostructures. In Florida the weathered limestone bedrock, which has highly variable engineering properties, can be found near the ground surface and its thermal properties will need to be incorporated into the design of such systems. Thermal conductivity values for split tension sized specimens were determined using a specially designed thermal apparatus. The apparatus is capable of determining four thermal conductivity values for each specimen, which provided a measure of variability of the measurements. Thermal conductivities ranged between 2.65 and 3.75 W/m-K with specimen measurement standard deviations and coefficient of variations as high as 0.415 W/m-K and 11.1%, respectively. The variability of the results can be attributed to both dissolution, which would decrease thermal conductivity, and dolotomitization, which would increase thermal conductivity. Thermal conductivity values are in the lower range of values reported in the literature.