Study On Crushing Parameter For Old Cement Concret Pavement And Overlay Structure

Crack and seat is one of the effective methods in old cement concrete pavements(CCP) rehabilitation. The construction control index of crack and seat in different subgrade strength and schemes of overlays for graded road after concrete slab fractured are presented. Popularization and application of old cement concrete pavement fractured technique have economic and social meaning because of resource conservation and environmental protection。The equivalent modulus of elasticity of pavement after rubblization and crack and seat which can be reference for finite element calculations is inspected on site using rigid bearing plate test.The crack state of concrete slab during crack is simulated basing on the crack and crush character of solid 65 element in ANSYS software. The influence of subgrade strength to it is also analysed.The construction control index of crack under different subgrade bearing strength has been put forward. It is shown that there is an obvious pertinency between subgrade strengh and hammer drop height, and different hammer drop height should accord with different subgrade strengh during crack and seat.The static response of pavement under different vehicle load is analysed using 2D model. It is considered that it is viable for grade one road to use semi-rigid base course plus 10cm asphalt concrete as overlays after rubblization. The fatigue failure of overlay is controlled by asphalt surface and will reduce when the thickness of base course decreases. The better the contact of cracked consrete slab and overlay is, the better the mechanics performance is.Finally, through the embedment, analyzes the new observation apparatus with grass-roots layer spread the flexural stress variation, and compared with the calculation results verified the rationality of the numerical calculation results.The article content for old cement road surface broken the popularization and application of the technology to provide the reference.