Study of Structural Characteristics of Asphalt Overlays on Airport Pavement with Damaged Load Transfer Efficiency of Joints

Abstract

In this paper, the real joint load transfer efficiency of airport pavement is calculated by combining the results of airport pavement deflection detection and ground-penetrating radar detection. Spring elements are used to simulate the actual load transfer efficiency of joints in ABAQUS. The impact of different asphalt overlays on the stress state of the critical point in the pavement is analyzed by the airport cement concrete pavement model. The result shows that adding a thin stress-absorbing layer with fine-graded and low modulus can effectively disperse the load transferred from the asphalt pavement to the cement pavement and the stress concentration at the joint under the asphalt overlay. Compared with airport pavement without a stress-absorbing layer, the tensile stress and shear stress at the critical point in the airport pavement asphalt overlay decreased by 24.62% and 22.49%, respectively. Therefore, the combination of the high-modulus upper layer and low-modulus lower layer can effectively reduce the tensile stress and shear stress at the critical point. In addition, increases in the thickness of the asphalt overlay can effectively improve the stress state at the critical point. When the thickness of the asphalt overlay changed from 13 cm to 21 cm, the maximum tensile and shear stress decreased by 8.82% and 8.92%, respectively. Finally, based on the analysis of the numerical simulation and field test verification, the optimal airport pavement asphalt overlay scheme is proposed.

Properties of SBS/MCF-Modified Asphalts Mixtures Used for Ultra-Thin Overlays

“…In the 1970s, France first proposed the use of thin overlays and ultra-thin overlays in the maintenance of asphalt pavement, and Nova Chip with a skeletal void structure was used for ultra-thin overlays in the 1980s [4]. In recent years, so as to heighten the performance of ultra-thin overlays, many scholars have begun to focus on improving the performance of asphalt [5][6][7][8]. Chen [9] and Zhou et al [10] added SBS and a tackifier into a conventional asphalt cement and found that the modified asphalt had higher viscosity and better high-temperature performance than the conventional asphalt cement.…”