2011 Volume 65 Issue 1 Pages 217-224
Passive thermography using solar radiation is efficient for internal diagnosis of concrete by means of passive thermography. However, the expected surface temperature of concrete varies greatly with weather conditions and internal defect state, and therefore appropriate judgment of parameters including diagnosis timing with regard to weather conditions is required to avoid misdiagnosis. Thus in this study, we carried out experiments and thermal conductivity analyses to investigate the effects of moisture conditions on temperature rise in normal and defective portions of a concrete surface. As the result, we clarified that even though standing water is observed on a concrete surface, the temperature rises sharply if the surface dries before solar noon, and that heat storage increases due to moisture in the surface portion, thus aiding diagnosis.
