Study On GFRP Dowel Bar For Cement Concrete Pavement

Joint is applied in cement concrete pavement to control the problems of concrete expansion and contraction brought by temperature and moisture change. At the same time joint is the weak part of cement concrete pavement, the pavement performance is largely determined by the joint system whose mechanical performance needs to be improved through dowels that will mostly appear as steel dowel bar currently. Yet there is a problem that steel dowel is easy to suffer from corrosion in the long-term application and the joint may be locked by dilatant produced by the corrosion process, which will stop the expansion and contraction of concrete slab when temperature changes or moisture changes resulting in large stress contact dowel bar around concrete and joint destruction of the system. So a new force transmission rod is necessary. Related research shows that GFRP(Glass Fiber Reinforced Polymer) dowel bar is a potential alternative materials. But because of the difference between GFRP and steel dowel bar, the series of parameters of size, spacing, and length are no longer applicable to GFRP dowel bar. Current research mainly focus on the feasibility yet without any reasonable standards for the use of GFRP. The main purpose of this paper is to obtain a series of parameters for GFRP dowel bar by the following method.First of all, to understand the material characteristics of GFRP dowel bar through access to literature so as to be clear about the stress condition difference between GFRP dowel bar and steel dowel bar in the process of application as well selecting the appropriate analytical model. Secondly, to calculate different performance in the process of the joint systems between steel dowel and GFRP dowel bar through reasonable theoretical model and a three-dimensional finite element model. Through the comparison with the standards of steel dowel bar, the required size, spacing and other data of GFRP dowel bar in the pavement system can be obtained. Finally, the relatively light property of GFRP dowel bar may lead to deviation in the application, this paper using analyzed the deflection of GFRP dowel bar through the method of three-dimensional finite element analysis calculation.Through the Verification of theoretical calculation and finite element model, the diameter,length, cloth rod spacing parameters for GFRP dowel bar as an alternative material are obtained. Through GFRP dowel bar deviation analysis the different effects under the action of deflection of GFRP dowel bar and steel dowel bar is obtained. The allowable deviation range of GFRP dowel rods different from steel dowel bar is also realized.