Equipment design and parameters recommendation of rubber modified 3D printed asphalt in pavement maintenance

Abstract

As an advanced technology for pavement crack maintenance with high automation level, high precision and high efficiency, 3D asphalt printing technology can effectively improve worker safety and ensure the stability of maintenance quality. In order to optimize the printing parameters of rubber modified 3D printed asphalt (R-3DPA), a three-axis asphalt 3D printer was developed in this study through the design and selection of each component, and it was used for the 3D printing of R-3DPA strips, layers, and structures. Based on the comparison of continuity, uniformity, and width of R-3DPA strips, the recommended extrusion nozzle diameter, printing temperature, and printing speed parameter combinations were superiorly selected. According to the analysis of filling degree, width error and thickness of R-3DPA layers, the optimal printing strip width was recommended. Through the evaluation of integrity, surface characteristics and accuracy of R-3DPA structures, the suitable printing layer thickness was determined. The test results showed that the three-axis asphalt 3D printer can be used to measure the parameters of R-3DPA, and the printing accuracy and scale meet the requirements. The recommended parameters for R-3DPA are an extrusion nozzle diameter of 2 mm, a printing temperature of 180 °C, a printing speed of 20 mm/s, a printing strip width of 2.25 mm and a printing layer thickness of 0.4 mm, resulting in structures with good integrity and precision.