Research On Pavement Performances Of Ultra-thin Wear Layers On Ultra-high Performance Lightweight Composite Deck

In order to effectively solve the problems of fatigue cracking of the steel bridge deck and the vulnerability of the pavement,the research team of the author put forward a new idea for the steel bridge deck based on ultra-high performance concrete to improve stiffness of the bridge deck and reduce the stress amplitude of the steel bridge deck:Ultra-high performance new combined bridge deck pavement system(Steel bridge deck-UHPC-Wear layer).In order to reduce the self-weight of the lightweight composite bridge deck of extra-long-span steel bridges,and to find an ultra-thin wear layer that matches the performance of the lightweight composite deck,this paper selects a resin asphalt overlay(EBCL)and thin polymer overlay(TPO)both with excellent performances and a thickness of only 8～12mm for researches.The mainly completed research work are as follows:(1)By conducting pull-out tests and shear tests of the composite specimen,the interlayer bonding performances of EBCL-UHPC and TPO-UHPC at room temperature and high temperature were explored.and the shear modulus E_d was proposed to evaluate the interlayer bonding state of the composite structure.The test results show that:The pull-out and shear failures of the two kinds of composite specimens all occured at the interface between the UHPC and the wear layer,indicating that the interface is probably the weakest part;The interlayer bonding performances of EBCL-UHPC and TPO-UHPC are excellent.Temperature has a significant effect on the bonding performances between the two types of materials,and TPO shows better stability under high temperatures;The simulation analysis of a real bridge on a Yangtze River Highway Bridge was also conducted and finite element calculations show that both TPO-UHPC and EBCL-UHPC can meet the requirements of interlayer stress under room temperature and high temperature conditions,and has sufficient safety reserves.(2)Through laboratory tests to simulate the aging under adverse environmental conditions,the durability and laws of deteriorations are explored:Under the unfavorable environments of high temperature,ultraviolet light,and water damage,the interlayer bonding perfoamnces of the two types of composite specimens have both decreased to some extent,but still maintained a good condition,showing a good resistance to aging;There are differences in the aging degree under different environments,and the rankes are as follows:Water damage>UV light>High temperature;TPO shows better durability under high temperature and UV light environment,and EBCL shows better stability under water damage.(3)After multiple aging cycles,the road surface performance of EBCL and TPO was explored,and the test results show that:After multiple aging cycles,the structural depth,BPN swing value,water permeability coefficient and mass loss rate of EBCL and TPO all have hardly decreased.Two types of wear layers both possess good properties of anti-skid,waterproof and anti-stripping.The impact of environmental aging on road surface performance is almost negligible;EBCL and TPO both have good service performances as wear layers and can provide a safe and comfortable driving environment.(4)Based on the experimental results and relevant engineering experience in this paper,the construction process is described in details:From the aspects of pre-construction preparation,interface treatment,thin stone pavement,quality control and precautions,the requirements are put forward to provide technical guidances for the application of ultra-thin wear layer on light-weight composite bridge deck in practical engineering.