Integrating the design of a pavement structure and its materials is fundamental to ensure that asphalt pavements possess adequate rutting resistance. In this study, a rutting prediction model was established to link mixture permanent deformation with pavement rutting in the process of integrating design. Several factors, such as the application environment (temperature and vehicle speed), service life (traffic volume), pavement structure, and mixture performance, were characterised. An exponential model was used, and a basic rutting prediction model was developed; the latter model involves mixture dynamic stability, shear stress of the pavement structure, axle loading repetitions, pavement temperature, vehicle speed, and pavement depth. Three different pavement structures were analysed through accelerated pavement rutting tests with an accelerated loading facility and through shear stress calculation. The corresponding asphalt mixtures were tested through rutting and creep tests on the asphalt mixture performance tester to determine the parameters of a simplified rutting prediction model with a reference speed of 20 km/h. A model of time hardening creep and loading time function was used to determine the relationship between pavement rutting and vehicle speed. The final rutting prediction model was established through adjustment of vehicle speed in the simplified rutting prediction model. An application method for the prediction model was also proposed through reference to rutting nonlinear superposition methods in the Mechanistic-Empirical Pavement Design Guide. Finally, the developed model was validated with the use of actual rutting data. However, more field rutting data are needed for further model validation and improvement.

To study and evaluate the adhesion between recycled concrete aggregate and asphalt, the contact angles (CAs) between droplet (water and ethanol) and recycled concrete aggregate (RCA), natural aggregates, and solid bitumen (matrix asphalt, SBS modified asphalt) were tested via the sessile drop method with an optical microscope. The surface free energy was then calculated. The CAs between hot asphalt and RCA and natural aggregates were tested via the hanging slice method. The adhesive energy between asphalt and RCA and natural aggregates were calculated based on the test results of the surface free energy and CAs. Then, the influence of RCA on the water stability and fatigue performance of the asphalt mixture was analyzed by testing the water stability and fatigue properties of hot mix asphalts containing RCA (HMA-RCA) with different aggregates and RCA dosages. The surface energy of the various aggregates and the CAs between aggregates and asphalts were sorted as follows: Granite > RCA > serpentinite > limestone. The surface energy and CA of RCA were very close to that of serpentinite. The adhesive energy between various aggregates and asphalt were sorted as follows: Limestone > serpentinite > RCA > granite. The adhesive energy between RCA and asphalt was also very close to that of serpentinite. The residual Marshall stability, tensile strength ratio, and fatigue performance of the HMA-RCAs were gradually reduced along with the increasing RCA dosage. This effect may be attributed to the fact that the adhesive energy between the RCA and the asphalt was less than that of water and that the asphalt was easily stripped from the RCA surface. Excessive RCA content in the aggregate can lead to excessive porosity of the HMA-RCA. The CAs and adhesive energy between RCA and asphalt showed significant effects on the water stability and fatigue performance of HMA-RCA.

The 7, 28, 60 and 90 day mechanical properties of CSCRA were experimentally tested, including unconfined compressive strength (UCS), resilient modulus, splitting strength and flexural-tensile strength. According to the test results, the strength growth equations and relation models of mechanical indexes are established innovative. The strength criteria of cement-stabilised recycled concrete aggregate (CSRCA) against fatigue failure was proposed based on load response of pavement, mechanical and fatigue properties of CSRCA as well as Miner’s theory of fatigue accumulation. Results showed that when the curing age was smaller than 60 days, the UCS and resilient modulus of CSRCA showed a V-shaped variation with the increase of recycled concrete aggregate (RCA) dosage, and decreased with the increasing of RCA content when the curing age was 90 days. Splitting strength and flexural-tensile strength of CSRCA increased slightly with the increase of RCA dosage. A fatigue equation of CSRCA was established, which reflected that the fatigue life of CSRCA increased slightly with the increase of RCA dosage. The strength growth equations could represent strength growth characteristics of CSRCA accurately. The UCS and splitting strength criteria of CSRCA against fatigue failure were proposed, which were correlated with pavement structure and layer, material properties and service life. It realised the goal of structure-material integrated control of CSRCA base or sub-base fracture.

Heat-reflective coatings, used to reduce the asphalt pavement temperature and urban heat island effect, have a good cooling effect; coating development, however, generally focuses on cooling. This study aims to design a heat-reflective coating with both durability and cooling effect by considering the functions of each component, improving the coating bond strength and abrasion resistance, and conducting laboratory tests and test section verification. The coating developed exhibits bond strength and abrasion resistance 20% and 49%, respectively, higher than those of ordinary coatings. The experiments reveal a cooling effect of red coating up to 10.2 °C, a bond strength of up to 1.20 MPa at 25 °C, and an abrasion rate of up to 25% after 60 min; the cooling effect is basically the same as that for traditional heat-reflective coatings, but the bond strength and abrasion resistance significantly improved. In the analysis of the test section, the cooling effect reaches 7.0 °C, the performance of anti-skid decreases little, and the coating is still usable normally after 4 months.

The interlocking force of aggregates, which is closely related to mixture gradation, is one of the main factors that influence the shear strength and rutting resistance of an asphalt mixture. Gradation is optimised by traditional methods, including the step-filling test and experimental tests on shear strength such as the uniaxial penetration test (UPT). However, both methods have disadvantages. Thus, research has focused on a virtual method based on the numerical simulation method (NSM). Here, a visual method for the UPT based on the NSM (UPT–NSM) is developed, which optimises the mixture gradation to improve the shear strength and rutting resistance of asphalt mixtures. The UPT–NSM results are consistent with those of an indoor test, with an error of less than 4%, thus proving the reliability of the UPT–NSM. From the perspective of the aggregate fraction, using the UPT–NSM can optimise the gradation better than the step-filling test in order to improve the shear strength and rutting resistance of the asphalt mixture. The anti-shear strength and dynamic stability of the asphalt mixture with gradation optimised by UPT–NSM are 25.5 and 27.0% higher, respectively, than those of the specified gradation.