An experimental study on thermal conductivity of concrete

Influencing factors on thermal conductivity of concrete are quantitatively investigated by QTM-D3—that is, a conductivity tester developed in Japan—and a prediction equation of thermal conductivity of concrete is suggested from the regression analysis of test results. To consider the interacted factors influencing thermal conductivity of concrete, mortar, and cement paste, seven testing variables such as age, water–cement (W/C) ratio, types of admixtures, aggregate volume fraction, fine aggregate faction, temperature, and humidity condition of specimen were adopted in this test. According to experimental results, aggregate volume fraction and moisture condition of specimen are revealed as mainly affecting factors on the conductivity of concrete. Meanwhile, the conductivities of mortar and cement paste are strongly affected by the W/C ratio and types of admixtures. However, age hardly changes the conductivity except for very early age. Finally, the conductivity of concrete is represented in terms of the aggregate volume fraction, fine aggregate fraction, W/C ratio, temperature, and humidity condition of specimen.