ABSTRACT
To mitigate the shear concentr ation of partial holes in groups, perfo bond connector with an easy-installed rubber ring was proposed. Then nine m odified push-out tests including four specim ens with one hole and five specimens with four holes were conducted to reveal the shear mechanism of the rubber-ring perfobond connector. The presence and thickness of rubber rings, the number of holes and the arrangement of rubber rings were investigated in the tests. The test results showed that the failure of perfobond connector consists of four stages, including the damage of bond, the shear failure of concrete dowel in the hole, the tension-shear yielding and the failure of perforated rebar. The yield slip of perfobond connector can be increased by 260% to 745% by employing the rubber ring, which was related to the thickness of rubber ring and the deformation ability of perforated rebar. The presence of rubber ring which decreased the area of concrete dowel reduced the shear capacity by 15%. The strain difference of steel plate in adjacent rows was reduced by placing the rubber rings on the first and the fourth rows, i ndicating rubber rings could be utilized to alleviate the non-uniform shear distribution. Finally, the existing form ulas of shear capacity based on previous m odified push-out tests were evaluated.
