Research On Flexible Screed Of Asphalt Paver

Targeting problems that the existing conventional rigid screed and leveling system can only reduce the longitudinal roughness, but can not take into account the transverse roughness and does not consider the loose laying settlement in the course of compaction, this paper points out the objective existence of the two-dimensional roughness of subgrade, brings forward a new concept called as flexible screed paving system. The system consists of two-dimensional roughness testing device of subgrade and flexible screed and adjustment device. The two-dimensional roughness testing device detects subgrade roughness in both longitudinal and transverse directions to provide a basis for screed adjustment. According to the test result for subgrade, flexible screed and its adjustment device form transverse curve of screed. The structure and control requirement of this kind of screed are completely different from conventional screed. The flexible paving system can give attention to subgrade roughness in longitudinal and transverse directions and reserve compacting settlement according to coefficient of loose laying, roughness degree of subgrade and its location, thereby eliminate or reduce reflection of subgrade roughness and improve flatness of pavement. This paper mainly aims at highway rut in period of major maintenance, including transverse wavelength of rut, depth, etc, focuses on paving curve of flexible screed and distributing of hydraulic cylinders that adjust deformation of flexible screed, and determine the mainly performance and structural parameters of flexible screed.. In order to find the structural flaws of screed, ANSYS is used in process of paving simulation. After simulating and modifying the structure again and again, the screed stress is reduced and screed structure is optimized. The results of calculation and simulation show: the flexible paving system which screed transverse curve can be changed according to plane roughness of subgrade can adjust loose laying depth of different regions and reserve compacting settlement, so the flexible screed can effectively improve pavement flatness, especially for highway major maintenance.