Flexural behavior of green RC beams with disposable glasses fibers in a marine environment

Using supplementary cementitious materials (SCMs) in concrete improves mechanical behavior and decreases the environmental pollution resulting from cement as a generator of greenhouse gases. On the other hand, the addition of disposable glasses as fibers to concrete can reduce cracking, increase ductility, and decrease environmental pollution too. Therefore, it seems that by the simultaneous use of SCM and plastic waste fiber in producing green concrete structures can reduce environmental pollution, improve mechanical behavior, and delay the cracking process, especially in marine. To achieve this objective, in the current research program, the effects of adding 0.5 % and1 % disposable glass fibers in form of ring or strip on the flexural behavior of ordinary green reinforced concrete (GRC) beams containing 10 % metakaolin/zeolite as SCMs were investigated at 28 and 180 days in the tidal environment of the Oman sea. According to the results, the cracking load (Pcr) of GRC beams was decreased up to 25 % and 32 % by adding ring and strip fibers, respectively. Moreover, adding fibers to GRC beams increased the maximum load capacity (Pmax) and flexural toughness (T) up to 28 % and 48 %, respectively. Also, green fiber reinforced concrete (GFRC) beams containing strip fibers had greater Pmax and T than ring fibers. Furthermore, metakaolin GFRC beams had higher Pcr, Pmax, and T than zeolite by 7 %, 9 %, and 7 %, respectively. Considerating the results, addition of ring fibers to the GRC beams increased the pre-cracking stiffness (SFpr) more than the strip fibers and decreased the post-cracking stiffness (SFpo).