Experimental Study on Anchoring Performance of Short-Lapped-Rebar Splices with Pre-Set Holes and Spiral Hoops

Abstract

The precast concrete structure has the advantage of a short construction period, less labor consumption, and less pollution. The lapped-rebar splice is a type of connection for assembled reinforced concrete shear walls in the precast concrete structure. In this study, the anchoring performance of a short-lapped-rebar splice with a corrugated metal duct and spiral hoops is investigated. A total of 30 specimens were designed considering the influences of the rebar diameter and the lapped length, and the tension testing of the splice was carried out. The results show that the specimens with 0.15 times the suggested length in GB 50010-2010 fail by the fracture of rebar, while the specimens with 0.1 times and 0.05 times the suggested length show the pull-out failure of rebar. The ultimate bond strength of specimens with the suggested length is higher than that of the conventional specimens. The stress of the anchored rebar in the short-lapped-rebar splices is distributed symmetrically along the longitudinal direction. The maximum bond stress of the anchored rebar reaches 35 MPa, which is approximately 1.4 times that in the conventional specimens. A semi-empirical model for predicting the ultimate bond strength of the short-lapped-rebar splice is proposed, and it shows good agreement with tested values; the average error estimated from the proposed model is only 4.49%.

Keywords

• short-lapped-rebar splice
• spiral hoop
• corrugated metal duct
• anchoring performance
• ultimate bond strength