In-Situ Tensile and Flexural Testing of Concrete Reinforcing Bars Made of Steel, Bamboo, and Rattan

• P. Adewuyi

  English

  Author

• Otukoya

  English

  Author

The deformation properties and flexural performance of concrete elements reinforced with twisted steel rebars,
rattan, and bamboo were compared in this research. Using a universal testing equipment, fifty specimens of each
material were tested for yield strength (YS), ultimate tensile strength (UTS), and elonga-tion. Stirrups were
primarily mild steel bars, and three beams with a concrete strength of 20 N/mm2 at 28 days were reinforced with
bam-boo, rattan, and steel bars of the same proportion. In order to assess the flexural behavior, the beams were
loaded center-point flexural according to BS 1881. Bamboo bars had a YS that was 13% of steel's and rattan bars
had a YS that was 45% of steel, while the UTS of the two materials were 16% and 62% of steel, respectively. The
elongation of rattan was 10%, that of bamboo was 7.42%, and that of steel was 14.7%. As a result, the natural rebars
did not meet the BS 4449 minimum standard of 12%. Bamboo and steel RC beams exhibited quadratic load-
deflection plots, but rattan RC beams exhibited a curved tendency. Rattan RC beams (RB) and bamboo RC beams
(BB) were 32% and 13.5% stiffer than steel RC beams, respectively (SB). Both BB and SB had a residual flexural
strength of 41% after the initial fracture, however RB only managed 25%. Additionally, BB and RB had moment
capacities that were 51% and 21% of the capacity of steel RC beams, respectively. The low bonding at the bar-
concrete interface and the high tensile strength of steel explain why natural rebars have much lower flexural
capacities than steel. While rattan requires additional pre-strengthening treatment for increased interfacial bonding
and load-carrying capability, bamboo bars are ideal for non-load bearing and lightweight RC flexural constructions.

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