Research On Preparation And Performance Of New Type Material For Bridge Deck Overlays

With the construction of domestic bridge especial long span steel bridge, damage occurs during the early period.It is very important to maintain good combination between deck overlays and bridge deck. It affects directly durability of deck overlays. At present, The materials for adhesive layer mainly are asphalt and the waterproof volume materials. As a result of the materials aging as well as the external environment influence, adhesive layer is weak unceasingly and finally damaged.Under current bridge swift and violent development background, research and development of new type material is vital to bridge deck overlay.New type material of bridge deck overlays has been prepared and analyzed in this study. One component moisture curable polyurethane was chosen for binder material because of its excellent flexibility and durability, and then bonding mechanism between polyurethane and aggregates was analyzed then. According to ISSA A143 II type gradation, Polyurethane-aggregate mixture was prepared with selected solidifying mechanism. Experimental results of polyurethane-aggregates material shows excellent direct tensile and shear properties, fatigue resistance, moisture resistance properties. This material can adhere to asphalt concrete and steel board tightly. The tensile strength of composite specimen is 1.52MPa (at 0℃). The shear strength between asphalt concrete and the material is 1.57MPa (at 0℃); the shear strength between steel board and the material is 1.75 MPa (at 0℃). In moisture and salt condition, The tensile strength of composite specimen is 1.45MPa (at 25℃). The shear strength between asphalt concrete and the material is 1.25MPa (at 25℃); the shear strength between steel board and the material is 1.64 MPa (at 25℃). Finally, Key technical index of this new type material is studied: The maximum polyurethane is 20%, water absorb pecent is 1.4%, flame-retardant property is first-grade.New type material of bridge deck overlays is an excellent bonding material for bridge deck overlay due to its excellent performance.