Simulation Analysis and Optimization of Temperature Field for Hot In-Place Asphalt Pavement Recycling.

The heating temperature field of asphalt pavement is a key factor affecting the quality of pavement heat-in-place recycling (HIR). Using the heat transfer characteristics of HIR, a three-dimensional heat transfer model was simplified into a one-dimensional heat transfer model along the depth direction. A temperature sensor was installed on the site to monitor the temperature change of the asphalt pavement at different depths under different heating powers, and the actual temperature and heat transfer model were highly compatible. Through this model, the influence of heater running speed and heater heat flux density on the temperature field of the asphalt pavement heated by infrared radiation (IR) was calculated by the finite differential method, and an optimal combination of heating is proposed. In accordance with construction continuity and minimum energy consumption principles, at the 3.0–3.5 m/min recommended running speed of the heating machine, the asphalt at a depth of 4 cm satisfied the temperature demand, but the asphalt on the road surface was prone to heat aging. The heating effect of the constant temperature variable power heating (CTVP) is ideal, but the continuous change in heating power increases the difficulty of construction. Constant temperature discrete power heating (CTDP) divides the ideal heat flux density curve into several stages according to the length of the heating plate in the heater, increasing the feasibility of constant temperature heating in engineering and reducing energy consumption. The mileage of roads in some countries has basically satisfied the needs of national development, and the research focus of road workers has gradually shifted from building new roads to the renovation and maintenance of existing roads. In order to meet the purposes of convenient transportation and environmental protection at the same time, construction optimization must be carried out in the process of road renovation and maintenance to ensure that energy is not wasted during the construction process, and the relevant requirements of construction specifications are met. At present, high proportion of paved roads throughout the world have asphalt pavement. HIR has gradually become a popular maintenance method in order to save resources. In this method, the heating temperature field of the original asphalt pavement plays a key role in the construction quality, and the temperature field is affected by many factors, such as the running speed of the heater and the heat flux density of the heater during the heating process. This study mainly considers the foregoing two factors, combined with the actual situation of the project, in order to find a heating method with excellent heating effects and simple construction. The heating effect of the pavement is further optimized, improving the quality of the project, while saving energy and reducing the project cost. [ABSTRACT FROM AUTHOR]