Abstract: Seepage through concrete cracks was identified as a critical factor inducing tunnel lining defects, and its evolutionary process was accompanied by complex energy conversion and heat exchange. However, the microscopic thermodynamic behavior was hardly captured by traditional methods. Therefore, the crack seepage mechanism was taken as the core research object in this study. Infrared thermography was employed as a diagnostic tool for temperature fields, supplemented by a high-speed camera, and laboratory seepage tests under various working conditions were conducted. The temperature evolution law and the intrinsic energy mechanisms in the crack area under isothermal water injection were specifically revealed. During the first water injection, a three-stage temperature change — an initial rise, a subsequent decline, and a final stabilization — was observed in the crack, which was governed by the competitive trade-off between hydration reaction heat and evaporative heat absorption. As the number of water injections was increased, the hydration heat was dissipated, and the temperature response was transformed into a two-stage pattern of direct cooling followed by stabilization. It was thus confirmed that evaporative cooling became the dominant energy consumption mechanism during the seepage process. In addition, the thermal response rate and spatial extent were significantly affected by the crack width, and the apparent crack size in the infrared thermograms was found to be larger than the actual size, which was attributed to the amplification of crack geometric information by thermal diffusion effects. The energy coupling mechanism in the seepage process was clarified by this study, and a theoretical basis was established for leakage diagnosis based on thermal signals.
张宪朕, 张淑坤, 吴星辉, 姜鹏. 基于红外热成像技术探查混凝土渗漏水裂隙试验研究[J]. 隧道与地下工程灾害防治, .
ZHANG Xianzhen, ZHANG Shukun, WU Xinghui, JIANG Peng. Experimental study on detecting water-leaking fractures in concrete based on infrared thermal imaging technology. Hazard Control in Tunnelling and Underground Engineering, 0, (): 1-16.
