Studies on Bond Slippage Properties of Concrete Specimen Repaired with Strain Hardening Cementitious Composites （SHCC）

Abstract:

Influence of strain hardening cementitious composite（SHCC） as repair material, transverse reinforcement rate of repair layer and frost damage on bond slippage behavior between concrete and steel bar was investigated through pull out test. Results indicate that the ultimate bond strength decreases by about 57% for the specimens repaired by SHCC and the ultimate slip deformation increases by 34%. All of the specimens fail in pull out mode （but for ordinary concrete specimens, they fail by splitting of the concrete cover）. With the increase of transverse reinforcement rate of specimens repaired with SHCC, the ultimate bond strength increases, the crack width on the surface of specimens becomes smaller. When the specimens fail, multi crack happens on the surface of repair layer and the crack width is between 003mm to 008mm. The very good frost resistance of the matrix of SHCC and the bond performance between SHCC and existing concrete reduces the influence of frost damage on the bond performance between steel bar and concrete.