Development and application of experiment apparatus for road material

Water impairment is the main disease in current express highway, with various damage modes, which can be explained as follows: the structure material is repeatedly scoured by the water flow, then the aggregate and fine stuff are carried off to due to the dynamic water pressure generated in the pavement by the wheel-roads. Hence, the test apparatus(High-frequency & High-pressure Dynamic Water Pressure Generator, which can generate sinusoidal cyclic dynamic water pressure, with peek value 1Mpa and frequency 0∼25Hz) is developed to evaluate the road material dynamic pressure capacity. Combined with tri-axial test apparatus, it can study the mechanical performance of the road material under cyclic dynamic pore water pressure, and provide a new and effective method for the farther study of the road material water impairment mechanism and tactics. This test apparatus is advanced in design, and can work properly with powerful function, believable data, and high precision. The study on the cement stability macadam specimen illustrates that: under the identical condition, the material strength decreases as the scouring frequency increases, while the plastic deformation increases with the scouring frequency. Copyright ASCE 2007.