Investigations on the Strengthening of Existing Highway Bridges Under Shear and Flexural Loading with Textile Reinforced Mortar

Many existing highway bridges in Western countries have deficits in shear and flexural capacity under static and cyclic loading due to increasing traffic loads and changes in code provisions. Therefore, a lot of structures are expected to require refurbishment and strengthening within the next years, especially due to the current condition of many older road bridges. Different methods with specific advantages and disadvantages have proven to be suitable for the shear and flexural strengthening of bridges. At the Institute of Structural Concrete ofRWTHAachen University (Germany), the effect of a retroactively applied textile-reinforced concrete (TRC) layer for the webs of prestressed concrete beams and bridge deck slabs and has been investigated. The TRC layer is composed of a carbon fiber reinforced polymer (CFRP) fabric and an efficient mortar. CFRP is corrosion resistant and has a higher tensile strength than rebar steel. Thin structural components with high load carrying capacities can be achieved. The webs of prestressed concrete beams (l = 6.5 m, h = 0.7 m) were strengthened with TRC and tested under cyclic and static loading to investigate the effect on the shear capacity of the longitudinal system. In addition, reinforced concrete slab segments (h = 0.28 m) were strengthened to investigate the effect of an additional TRC layer on the shear and flexural capacity of bridge deck slabs. In this paper, the impact of the strengthening layer on the increase in the load carrying capacity in comparison with non-strengthened reference specimens are presented.