Experimental Study On Dynamic Water Erosion Damage Of Cement Stabilized Macadam Base

A large number of engineering practices show that the road damage is mostly related to water.The hydrostatic soaking and hydrodynamic erosion are two main action forms of semi-rigid base materials.This thesis is supported by the science and technology project of Hebei Province(Nos.16275426),and the Hebei Province graduate student innovation project(Nos.CXZZSS2017092).The dynamic water erosion experimental device was developed and employed to investigate the effects of hydrodynamic erosion on cement stabilized macadam base.The water damage phenomenon of representative pavement were investigated,and the main water damage forms of semi-rigid base asphalt pavement were studied.The dynamic water erosion experimental device composed of tank,erosion platform,hose,booster pump and nozzle was developed.The samples of typical semi-rigid base material,i.e cement stabilized macadam,were prepared.The hydrodynamic erosion tests were carried out,and the unconfined compressive strength and erosion quantity,erosion depth were tested.The influence laws of the erosion action time and erosion frequency on the erosion quantity,erosion depth and compressive strength were researched.The changes of apparent morphology and unconfined compressive strength of the specimens before and after erosion were analyzed.The pollution of road runoff rainwater in Shijiazhuang city was investigated,and artificial rainwater was prepared.Then the static rainwater immersion test on cement stabilized macadam specimens was carried out.The compressive strength of the specimens before and after soaking was tested,and the influence law of rainwater soaking on the strength of specimens was analyzed.Based on above researches,the damage development process of semi-rigid base under dynamic water erosion was analyzed,and the erosion damage mechanism of the cement stabilized macadam base was studied.The technical measures to prevent and control the water damage of pavement were put forward,such as permeable cement stabilized macadam base,etc.