Study On Basalt Fiber Reinforced Polymer Tie Bar

Cement concrete pavement usually are designed with joints to reduce the temperature and humidity stress. In order to maintain the integrity of the pavement, generally tie bar is adopted in the longitudinal seam, and dowel bar is adopted in the horizontal seam. At the present stage, the tie bar used in China transportation structures is mainly steel based. Steel tie bar is unavoidably suffered to corroding substances and other aggressive phenomena, which affect the life of the pavement, especially in the northeast China where deicing agents are widely used. Therefore, many scholars all over the world are dedicated to the study of new materials to replace steel bars used in the pavement structure. On account of the excellent physical and chemical properties, basalt fiber reinforced polymer (BFRP) has attracted a lot of attention from civil engineers and it is gradually applied widely.The objective of this study was to study the applicability of replacing the steel road bar by BERP in pavement. By using ABAQUS finite element software to establish three-dimensional model of pavement structure and analyzing the mechanical responses of pavement structure under different vehicle loads in real construction sites, the most unfavorable load position is identified. Under this position, the applicability of the BFRP tie bar and the force characteristics of the pavement and the tie bar under different length, spaces and diameters are analyzed. Finally, by considering the effect of temperature load and the influence of soil intensity factors, the optimal layout scheme of BFRP tie bar is determined. Systematic study of BFRP tie bar’s performance in the road has solved the damage problem caused by steel corrosion to the pavement structure.According to the results obtained from the present study, the following can be drawn:under different load locations, the pavement deflection value and the tensile stress on the slab bottom of BFRP tie bar are not much different compared to the ones of steel tie bar. The shear stress of BFRP tie bar is comparatively larger while tensile stress is smaller, and both are within the allowed range. With the increase of BFRP tie bar diameter, the pavement deflection, the maximum tensile stress and the stress of the tie bar are all decreased, as well as the pavement crack under temperature load and the depth of camber. The pavement deflection and maximum tensile stress increases with the increase of the spaces between the tie bars, as well as the pavement crack under temperature load and the depth of camber. With the increase of the tie bar length, the mechanical response of pavement structure is not fluctuating and reaches the minimum when the length of tie bars is 700mm. Therefore, as long as the tie bar’s length is guaranteed, the shear stress lever won’t be too concentrated. Under vehicle load, the mechanical response of pavement structure equipped with BFRP tie bar in stronger roadbed strength is less than the mechanical response under weaker roadbed strength. Therefore, if the strength of roadbed could be guaranteed in the construction, the pavement equipped with the BFRP tie bars could have a longer service life.