A simple laboratory system for measuring thermal conductivity has been developed which utilizes a heat-flux transducer on each side of the specimen. Because previous studies have characterized the thermal contact resistance, the need to embed temperature sensors in the specimen was avoided. The specimen can be sealed in a plastic bag. This enables measurement of the thermal conductivity of specimens with varying amounts of moisture. Four different concretes have been studied: a standard concrete, a micro-concrete used for model structural analysis, a standard shotcrete with metal fibers, and a foamed light-weight (cellular) shotcrete. Thermal conductivity increased linearly with moisture up to high moisture levels; the values at 27°C range from 1.00 to 1.85 W/(m-K) for concrete, 1.46 to 2.03 W/(m-K) for microconcrete, 0.98 to 1.83 W/(m-K) for shotcrete, and 0.14 to 0.36 W/(m-K) for cellular shotcrete. Data have a reproducibility of better than 2%. The conduction processes in the materials are discussed briefly.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.