Study On Temperature Stability Of GFRP-SMA Composite Steel Deck Pavement

Bridge deck paving is one of the key technologies in the construction of long-span Bridges.It is a key problem to improve the stiffness of the paving layer and reduce the influence of the temperature stored in the high temperature season on the paving materials of steel box girder Bridges without increasing the dead load.Sticking a layer of glass fiber reinforced plastic(GFRP)sheet at the bottom of steel deck pavement layer can effectively improve the stiffness of the pavement layer and improve the compatibility between the pavement layer and the steel plate without increasing the self-weight,thus extending the life of the steel deck pavement layer.In view of the influence of temperature on the pavement layer and the problems raised by the previous studies,the pavement layer material in the pavement structure pasted with GFRP sheet is slightly improved in this paper,and the stability of the pavement layer under the action of temperature is further studied.Due to sticking GFRP sheet of asphalt concrete pavement structure of high temperature resistance to deformation ability has certain requirements,this paper studied the hybrid fiber affect the performance of the high temperature stability of SMA asphalt concrete,and preparation of the high temperature stability performance better apply it to the composite asphalt concrete pavement,then under the action of the composite pavement's temperature stability test,including interlayer stability test,high temperature stability test,thermal compatibility test;Finally,the permanent deformation of pavement layer under the influence of vehicle axle load and emergency braking at different temperatures is calculated by numerical simulation,and the influence of GFRP sheet on the permanent deformation of pavement layer is studied.The experimental results and numerical simulation show that when 0.3% glass fiber and 0.2% polyester fiber are mixed,the high temperature stability of SMA asphalt mixture is improved by 67% and the indoor test verifies that the asphalt mixture meets the requirements.When steel-GFRP-SMA is combined and bonded with epoxy resin,its interlayer stability is improved,especially at high temperature.Bonding GFRP at60 ? can improve the interlayer stability by 14%.The new composite structure presented in this paper also has excellent high temperature stability performance,which is better than the traditional two-layer SMA pavement in dynamic stability and rut depth,and through the thermal compatibility test,paste GFRP between steel plate and asphalt concrete,will not cause thermal incompatibility and damage;The most unfavorable temperature for permanent deformation of pavement layer is 60?.After 50,000 axial load at 60 ?,the pavement layer pasted with GFRP reduces the vertical maximum permanent deformation of 12%.Although the paste of GFRP will increase the shear strain of pavement during emergency braking,it does not increase the permanent deformation of pavement.On the contrary,after 5,000 times of emergency braking at60?,the maximum deformation along the driving direction is reduced by 29%,and therelative maximum permanent deformation is reduced by 9%.The relative maximum permanent deformation in the vertical direction has been reduced by 17%.Through the above research,the pavement structure of pasted GFRP sheet can resist the action of temperature,forming a durable and stable pavement structure,and promoting the application of GFRP sheet material in the pavement layer of long-span bridge.