Experimental study of 90° hook and standard hook at the end of reinforced concrete beam stirrup

Abstract

Part of shear forces on reinforced concrete structures, will be borne by stirrup. According to Indonesia concrete standard, a closed stirrup must be used in earthquake prone areas. The end of the stirrups should be a hook with an angle ≥ 135°. The focus of this research is the modification of the hook shape on the stirrup reinforcement. This research is expected to design the shape of hook which good performance on shear holding. The basis of this research is experimental testing in the laboratory by cyclic loads. The specimens consisted of 2 pieces: TG1 and TG2. TG1 is a specimen with an angle135° end-hook shape according to SNI provisions. TG2 is a specimen with an angle 90° end-hook shape. The two specimens are reinforced concrete beams (250mm x 400mm x1700 mm). From the test, it is proofed that the two specimens are collapsed by shear. The ultimate load on the second specimen is greater than the ultimate load of first one, Pu1 = 245 kN and Pu2 = 270 kN. In addition, the deflection of the second specimen is greater than the deflection of the first one, δ1 = 12 mm and δ2 = 14 mm.

Effects of Earthquakes on Buildings in the Ibero-Maghrebian Region

“…A greater number of stirrups in the coupling node, progressively reducing the distance between them towards the intersection core, would increase the structure resistance and distribute the displacement energy along the full length of the columns, not transferring all the cyclic reversal of loads to the column-beam joints (Figure 25f). In addition, in areas with a moderate to high level of seismicity the stirrups should be anchored to the longitudinal rebars, overlapping 135° hooks [24] to avoid the opening of the closed-loop and Effects of Earthquakes on Buildings in the Ibero-Maghrebian Region DOI: http://dx.doi.org/10.5772/intechopen.94739 outward bending of the rebars (Figure 25e). The Turkish Earthquake Code 2007 and Indian Standard IS13920-1993 are two examples of the implementation of these earthquake-resistant requirements.…”

Shear Strengthening Behavior of Reinforced Concrete Beam Using Non-Stressing Strands

“…The end of the stirrups for all specimens made a hook with an angle of 135 degrees (Badan Standarisasi Nasional 2013). The uses stirrups with 90degree ends but the ends of the stirrups are bound with wires can receive load the same with the 135-degree stirrups (Susanto et al 2020).…”