DEVELOPMENT OF MODEL TEST SIMULATING CONCRETE PAVEMENT PUMPING AND SUBBASE EROSION

Abstract

 A scaled model experiment has been developed to visualize the process of pavement pumping and subbase erosion at pavement joints. The experimental device simulates uni-directional cyclic traffic loading on a circular track made of transparent acrylic container with an outer diameter of 350 mm and a depth of 120 mm. Fully saturated silica sand #6 and a transparent acrylic plate with a joint were used as subbase layer and pavement slab, respectively. The results indicated gradual ejection of subbase sand and water through the pavement joint under repeated traffic loading. According to the video analysis, the subbase surface was firstly eroded beneath the approach slab and then eroded more beneath the leave slab. The amount of subbase erosion by pumping varied with the traffic speed, which could be caused of the speed of pavement slab deflection and recovery.