Shear strengthening of continuous prestressed concrete beams with precast SIFCON laminates subjected to monotonic and repeated loads

Abstract

Slurry Infiltrated Fibre Concrete (SIFCON) is one of the recently developed construction material that can be considered as a special type of high performance fibre reinforced concrete (HPFRC) with higher fibre content. This study describes the findings of an experimental research to determine the contribution of Precast SIFCON Laminates to the enhancement of the shear strength of continuous prestressed concrete beams. Precast SIFCON Laminates were used in the investigation. It was decided to test six two-span prestressed high strength concrete continuous beams with rectangular cross-sections, each of which had a rectangular cross section. In this case, two beams were left un-enhanced as a control, and the other four beams were strengthened with varied arrangements of Precast SIFCON Laminates. The variables chosen were several wrapping strategies for the Precast SIFCON Laminates, which were then tested. The aim was to develop a better understanding of the shear contribution of Precast SIFCON Laminates and to investigate the effect of repeated loading. The results indicate that the strengthening the maximum shear regions with precast SIFCON laminates glued by epoxy resin led to improve the shear behavior the delay in first crack appearance time reached (26.4%−105.7%), Increased the ultimate shear capacity of the tested beams (19.2%–46.5%), The improvement in stiffness about (94.5%–144.9%) and the Experimental results explained that the ultimate shear strength for beams that are tested under repeated loads is a little reduced (2.2%–3.8%), comparing with the strength of the same beams under monotonic static loading.