The effect of raw material source on concrete duct bank thermal resistivity

Past experiments provided a method of determining concrete thermal resistivity using the constituents of the concrete mix. At that time material from only one source was used in the experiments. The question was raised whether the source of the sand or cement would affect the thermal resistivity of the concrete. This paper describes an experiment designed to determine whether the source of the sand and cement would affect the thermal resistivity of a concrete mix. The experiment performed determined that the source of the raw material will affect the thermal resistivity of concrete. This paper describes the experiment and includes the analysis of the gathered data. The experiment showed that the source from which both sand and cement was procured does have an effect on the final resistivity of concrete, and will affect the resistivity values that are used when determining the ampacity of cables encased in concrete duct banks.