Bond-Splitting Strength of Reinforced Strain-Hardening Cement Composite Elements with Small Bar Spacing

Strain-hardening cement composites (SHCC) show excellent mechanical behavior that is characterized by tensile strain hardening and multiple fine cracks. A suitable application of SHCC for bond improvement involves reducing the cover thickness and bar spacing of the main bars. To investigate the bond behavior of reinforced SHCC elements and to propose a predicting method for bond strength, the pullout bond test and beam bond test are conducted in which small cover thickness and bar spacing are used. The results of the pullout bond test show that the bond strength of SHCC is higher than that of conventional concrete, which is expected by the "partly cracked elastic stage" of the cylindrical model by Tepfers. It is considered that the tensile stress distribution of SHCC surrounding main bar corresponds to the "plastic stage." The results of the beam bond test also show that the bond strength of SHCC has a higher value.