Strengthening of One-Way Slabs Using Composite Laminates of HPFRCC Including Synthetic Fibers PPS

Some available One-Way reinforced concrete slabs show weak structural performance due to reduced flexural capacity and environmental deterioration. Some of these buildings and bridges have been severely damaged due to natural disasters such as earthquakes, fatigue of materials, and so on. Therefore, repairing and strengthening these structures using modern materials (such as high-performance composites) which have quite similar behavioral characteristics to concrete, can be vital and economical. In addition, it has other characteristics, including strain hardening behavior under tension and affordable cost. In this study, the behavior of slabs reinforced with precast Laminates of High-Performance Fiber-Reinforced Concrete Composite (HPFRCC) made of synthetic fibers was investigated with the help of full-scale test models and near-surface mount method (NSM). For this purpose, 12 specimens of the one-way slab were constructed. In the construction of these specimens, it has been used the same mixed design with characteristic strength f'c=21 MPa in accordance with the ACI318 regulation. Their dimensions are 1200×500 ×100 mm. A reinforced slab with four bars (No.8) in the tensile area was considered as the normal reference slab. The rest of the slab was weakened by reducing 50% of the tensile bars. Among weak slabs, a slab was defined as a reference slab and the other 10 slabs were reinforced with HPFRCC Laminates in the tension area. Composite Laminates were attached to the slab by epoxy grout and using the NSM method. All slabs were evaluated by a pure one-point bending test after preparation. Forces and displacements were recorded during the test process and the situation of cracks was examined. The results of this study indicated that the flexural strength of reinforced slabs compared to unreinforced weak slabs had a growth of 2 to 3 times and their displacements were limited.