Fatigue Analysis of FRP Strengthened RC Slabs Reinforced with Plain Bars Under Moving Load

Abstract

Abstract. In Japan, old RC bridge-deck slabs were economically designed by small thickness without considering the fatigue resistance. These slabs are subjected to a huge repetition of moving loads. Therefore, they are suffering from fatigue damage. This damage is more significantly observed than that of slabs reinforced with deformed bars. To extend their fatigue life, a suitable strengthening technique is required such as externally bonded FRP sheets. Using numerical method for predicting the improvement in their fatigue life is strongly beneficial to take full advantage of this strengthening technique. This study presents a proposed numerical method based on bridging stress degradation concept to analyze two full scale RC slabs reinforced with plain bars under moving load. One of them is strengthened with externally bonded FRP sheets in longitudinal and transverse directions on the slab bottom surface. The interfacial bond behavior between FRP sheet and concrete surface with its degradation due to fatigue loading is implemented. This study provides the propagation of cracked elements, center displacement evolution, cracking pattern and FRP strain. For the strengthened RC slab, the major crack opening is restricted by the contribution of FRP sheets in longitudinal and transverse directions. Therefore, the strengthened RC slab shows longer fatigue life and smaller deformation. By comparing these numerical results with the experimental results, the current numerical method provides a good agreement.

Evaluation on mechanical properties of high‐performance biocomposite bridge deck structure: a review

“…In conclusion, FRP bridge deck has become a variety of possible solution to the above fatigue problems, and today its fatigue performance is also a hotter topic. [63,64] Drar, et al [65] put forward a numerical method based on the concept of bridging stress degradation to study the mechanical behavior of two full-scale RC slabs under moving loads. One of them was strengthened by externally bonded FRP sheets along the longitudinal and transverse directions at the bottom of RC slab.…”

“…Drar, et al [ 65 ] put forward a numerical method based on the concept of bridging stress degradation to study the mechanical behavior of two full‐scale RC slabs under moving loads. One of them was strengthened by externally bonded FRP sheets along the longitudinal and transverse directions at the bottom of RC slab.…”