Asphalt Pavement Pothole Repair Using the Pre-Heating Method: An Integrated Experiment and Modeling Study

Pothole repair in asphalt pavements is one of the most common highway maintenance treatments. Improving the longevity of asphalt patch can increase driving comfort, improve road safety, and reduce agency and user costs. This study investigated the effectiveness of pre-heating on pavement pothole repair using laboratory tests, field measurements, and numerical modeling. A test section with artificial potholes and temperature sensors was built for the study. The potholes were repaired using hot-mix asphalt (HMA) after pre-heating using an infrared heater. Laboratory tests were performed on field cores to measure interface shear and tensile strength between patch material and existing pavement and the cohesive tensile strength of patch material. Numerical models were first validated using field temperature measurements and then used to determine the required heating time for reaching the targeted temperatures under different infrared radiation powers and field conditions. The results show that pre-heating increases the temperatures at pothole edges and surfaces and promotes better bonding. With the application of pre-heating, the greater interface shear and tensile strength were found between patching material and the surrounding pavement, in addition to greater indirect tensile strength and lower air voids of HMA patch. To reach the targeted temperature in 3-min heating under different ambient temperatures, certain ranges of power were proposed depending on the infrared radiation power and pothole size. It was found that using high-power heating within the proposed ranges can increase heating efficiency and reduce energy consumption.