| According to the problems of reflection cracks in the joint section between newand existing pavement which are caused by differential settlement between new andexisting subgrade, and combined with the600m trial road of K6+000~K6+600ofexisting road widening project linking provinces from Chengguan (Dushan), KaihuaCounty, Quzhou City in Zhejiang Province to Baishaguan in Jiangxi Province, theanalysis of differential settlement resistance for joint section between new andexisting pavement reinforced with double twisted steel wire mesh were made with agreat quantity of finite element analysis and indoor experimental tests, which has bothimportant theoretical and practical significance for ensuring asphalt pavementperformances of existing road widening project.1) The existing road widening projects which had been completed in our countrywere selected to investigate the distresses of asphalt pavement. The study indicatesthat one of the main causes of pavement distress is the differential settlement betweennew and existing subgrade, and the general characteristics of the distress wereobtained.2) The influence laws of mechanical responses of the4schemes, which aredouble twisted steel wire mesh laying between the upper course and the lower course(Scheme one), between the lower course and the base (Scheme Two), between thebase and the subbase (Scheme three), and without unreinforced, were analyzed underthe existing conditions of differential settlement between new and existing subgrade.The following conclusions were obtained. Scheme one was most effective fordifferential settlement resistance, compared with the unreinforced scheme, themaximum tensile stresses at the top of pavement and at the bottom of upper course,lower course and base as well as the surface vertical deformation values down centralwheel loads were reduced by53.4%,52.5%,52.3%,0%and60.6%, respectively.Scheme two is second, and Scheme three is worst.3) While double twisted steel wire mesh, earthwork cloth, glass fiber grid andgeotechnical grille are respectively laying between the upper course and the lowercourse, the influence laws of mechanical responses were analyzed under existingdifferential settlement between new and existing subgrade. The following conclusionswere obtained. The double twisted steel wire mesh was most effective reinforcement, compared with the unreinforced scheme, the maximum tensile stresses at the top ofpavement and at the bottom of the base as well as the surface vertical deformationvalue down central wheel loads were reduced by53.4%,0.17%and60.6%,respectively. While double twisted steel wire mesh, earthwork cloth, glass fiber gridand geotechnical grille are respectively laying between the lower course and the base,the results show that the reinforcement effects of the double twisted steel wire meshwere also the best. Compared with the unreinforced scheme, the maximum tensilestresses at the top of pavement and at the bottom of the base as well as the surfacevertical deformation value down central wheel loads were reduced by7.88%,0.52%and2.53%, respectively.4) The bending tests at low temperature and the tests of differential settlementresistance were designed in accordance with the wheel load position and the jointsection of new and existing pavement. The flexural tensile strength and the maximumflexural tensile strain of specimens were applied to characterize the flexural tensilecapacity of the reinforced specimens. The residual utmost loads were applied tocharacterize the capacity of crack development resistance for the reinforced materials.The results show that the double twisted steel wire mesh enhances the pavementcapacities of differential settlement resistance and crack development resistance to agreat degree. It has the absolute advantages than other geotechnical reinforcementmaterials.In brief, the researches can provide a scientific basis for the reinforcementtechnology and the capacity of differential settlement resistance in the joint sectionbetween new and existing pavement. |
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