Accelerated Loading Testing Of MA Steel Deck Pavement Of Hong Kong-Zhuhai-Macao Bridge

The Hong Kong-Zhuhai-Macao Bridge is the Century Super Project.The social impact of its deck pavement durability is extremely significant and politically sensitive.Steel bridge deck pavement puts high requirements on paving materials and structures.MA cast pavement materials is the one of the most advanced steel deck pavement materials,and their high temperature and fatigue properties are a special concern.Use performance requirements.To test the durability of materials,it is impossible to make a simple indoor test.It is not convincing to carry out numerical simulation alone,and it is difficult to make decisions in applications.GMA(using GA production process mixing MA pouring bituminous mixture)is a brand-new MA process to solve the huge scale,tight construction period and strict quality requirements of the steel bridge deck pavement project of the Hong Kong-Zhuhai-Macao Bridge project;There are no successful experiences for this kind of process.In order to ensure the high quality completion of the bridge on schedule,it is necessary to understand the mechanical properties and long term road performance of GMA in a short period of time.The MLS66 accelerated loading equipment was used in the test.The large scale full scale accelerated loading test was used.The short term loading(high temperature rut test for one day and fatigue performance test for about 20 days)was used to simulate the vehicle load and environmental conditions of the bridge deck during the design service life.Under the following conditions,a comparative study was conducted on two different deck paving materials and structures,the British traditional MA and the modified GMA,to test the high temperature performance and fatigue structural performance of the materials,and to recommend the proposed steel bridge deck of the Hong Kong-Zhuhai-Macao Bridge.Structural systems provide scientific evidence.The control factor of bridge deck pavement fatigue failure is the surface lateral tensile strain.The fatigue acceleration test model is designed in detail based on the similar principle that the maximum lateral tensile strain of the pavement surface is equal.A large scale full scale steel structure test model is made based on the design calculation results.The model paving test components were paved according to the material,proportion and actual full foot thickness of the MA,and the scientificity and reliability of the model were fully demonstrated.Through two tests of bridge deck pavement fatigue and performance accelerated loading tests,it is verified whether the pavement materials of MA and GMA can meet the design requirements of fatigue resistance,and the process,monitoring and data processing of accelerated loading fatigue test are introduced in detail..The rebound strain level measured by the fatigue test at the most unfavorable position is basically consistent with the design value of the accelerated load fatigue test,and the correctness and scientificity of the accelerated load fatigue test model are verified.After the 2 million-time fatigue performance accelerated loading test of the MA process bridge deck pavement system and the GMA pavement system,no fatigue cracks appeared,which can meet the fatigue performance design requirements of bridge deck pavement materials.In the high-temperature rutting accelerated loading test,the deformation of the bridge deck pavement is mainly affected by the compressive stress and shear stress of the wheel load.The high temperature rutting of the asphalt pavement mainly depends on the nature of the material itself,and sufficient rigidity is required during the test.Supporting,it is more reasonable to use the key sections of the real bridge box girder structure as the design model.The transverse rib spacing and the thickness of each plate are basically consistent with the real bridge model to meet the support conditions of high temperature rutting test.Accelerated loading test results show that the high temperature performance of the MA or GMA pavement structure produced by the improved GA process can reach even slightly better than the MA pavement structure produced by the British traditional process.At the same time,the fatigue performance of the GMA cast asphalt concrete can reach the British standard system.It is required that the GMA process effectively solves the problem of production ergonomics when constructing the bridge deck of real bridges,and realizes the goal of localizing the GMA pavement assembly technology.