Hybrid-Bamboo Rebars: Bamboo Trunks (Bambusa Vulgaris) with Polypropylene Attached as an Alternative to Typical Bamboo Rebars in Concrete Beams

Abstract

Various past studies suggest that utilizing this sort of rebar is viable for economical and low-rise residential structures where steel is hard to obtain and the ductility demand of the loads is low. Bamboo rebars show a competitive flexural strength that can be used in structural applications like concrete beams. Furthermore, polypropylene fibers can be used in the construction field. It can be mixed with concrete or used with concrete structures to further enhance the strength, as it offers enough tensile strength. The researchers utilized bamboo rebars as a control sample, and a bamboo with polypropylene attached as an experimental sample to compare whether the experimental sample exhibits a notable variation in flexural strength when incorporated into concrete. There are a total of 18 samples divided into (2) specifications: first, the concrete beams with traditional bamboo rebar (16mm); second, the concrete beams with bamboo coated with polypropylene plastic (16mm, with an additional 4mm of coating). The testing utilized a Universal Testing Machine to obtain the modulus of rupture (MOR) of the concrete beams. The findings indicated that bamboo with polypropylene coating has better flexural strength results compared to normal bamboo, for all 7-day, 14-day, and 28-day curing times. The results show as follows: in the 28th day curing time, experimental samples showed an average flexural strength of 7.52 MPa, whereas the control samples exhibited an average flexural strength of 5.51 MPa. With the utilization of the one-way ANOVA hypothesis testing, it shows a drastic difference between the flexural strength of both groups. Furthermore, the study found that bamboo with polypropylene coatings exhibits greater flexural strength than conventional bamboo rebar.