Effects of Hybrid Fiber on Flexural Behavior of Green RC Beams in Oman Sea

Steel rebar corrosion because of the cracks in marine reinforced concrete (RC) structures is the main type of deterioration that leads to decrease the load-carrying capacity, ductility, and service life. The use of different fibers such as steel fiber (SF), glass fiber (GF), and polypropylene fiber (PF) in RC beams can reduce the cracks and increase the load-bearing capacity and toughness of RC beams. Moreover, it seems that RC beams containing hybrid of SF, GF, and PF have been higher flexural capacity and toughness rather than RC composites with only one type of fiber. However, the role of mono or hybrid fiber will be depended on environmental conditions. Consequently, load-bearing capacity and toughness of Green RC beam with ۱۵% metakaolin (MK) as a cement replacement, containing SF, PF, GF, (S+P)F, and (S+G)F as fibers, at ۲۸, ۹۰, and ۱۸۰ days in tidal zone of Oman Sea were determined. The dimension of the beams was ۲۰۰×۲۰۰×۷۵۰ mm. The fibers included macro and microfibers. Macro fiber was steel with ۵۰ mm length. Microfibers were GF and PF with ۱۲ mm length. Results indicated that by the addition of PF, GF, SF, (S+P)F, and (S+G)F to RC beams the load-bearing capacity and toughness are increased up to ۴۱%. Meanwhile, the hybrid effect of fiber was more than the mono one.

Keywords:

Marine tidal zone , Glass fiber , Polypropylene fiber , Steel fiber , Toughness.