Research On Bond Performances Between UHPC And Upper Layer

In order to solve the problems both deck structure fatigue cracks and pavement early damages,a Lightweight Composite Deck System with Ultra-high performances concrete(UHPC)was developed.It was made up of UHPC and 20?40mm bituminous mixture/or 10?15mm Thin Polymer Overlay(TPO).In this paper,the research on interface bonding performance between UHPC and upper layer was carried out,and the following works were completed.Though domestic and foreign research status on interface bonding performance for steel or concrete deck pavement,understanding the main factors affecting the interlayer mechanical properties and the existing problems.Since both UHPC and surface layer of the new composite bridge system are thin structure,the interface bonding for UHPC-upper layer should be focuse majorly.The Experimental study on interface bonding performance of UHPC-asphalt pavement was conducted.The tests indicated that,at 20 ?,the shear strength were respectively 2.12MPa,2.54MPa,0.71MPa and 0.80MPa for 60%embedded stone,80%embedded stone,shot blasting 1 and shot blasting 2.And at 60? the shear strength were 1.39MPa,1.85MPa,0.41 MPa and 0.450MPa,respectively.Compared with the shot blasting,the surface of UHPC with 60%?80%embedded stone would significantly improve interlaminar mechanical properties.The Experimental study on interface bonding performance of UHPC-TPO was conducted.The results show that the bond strength of UHPC-TPO are respectively 4.27MPa?2.19MPa and 3.44MPa with shot blasting 2 on UHPC surface at 20??60?and after long-term aging,which indicate excellent bond performances between the layer.After 15 freeze-thaw cycles,the shear strengths between UHPC and TPO is 11.55MPa,the bond strength is 3.22MPa and the expulsion rate of aggregations is about 0.05%,and the water stability is good.Based on the freeze-thaw cycles tests,it can be found that the ralations between remaining strengths of the interlays are exponential function with the times of freeze-thaw cycles,and the shear strength and the bond strength are of a good correlation.Finally,combined with finite element analysis and laboratory tests,the engineering feasibility?scope of application and influences of interface treatments on the composite pavement system were evaluated.The research shows that for UHPC-asphalt pavement,it is suggested that UHPC surface with embedded stone should been choose,where are the hot areas,heavy traffic or extra heavy traffic road,continuous long and steep longitudinal slope,bridge deck pavement and so on,having high demands for shear strength and anti-slip properties,while shot blasting should been used for ordinary road engineering as more convenient way of construction.For UHPC-TPO,in general,TPO can be paved after removing the floating slurry dust and spraying the resin binder on UHPC surface.In the case of the high demand of interface strength for overload traffic roads and important traffic roads,shot blasting can be taken as interface treatment.