Experimental study on bond behaviour between BFRP bar and engineered cementitious composite

• Effects of various parameters on bond performance between BFRP bar and ECC are presented.
• Change mechanisms of bond behaviours are discussed.
• PVA fibres in ECC matrix enhance the bond performances between BFRP bar and cementitious matrix.
• Some factors are recommended to provide sufficient bond between BFRP bar and ECC matrix.

To understand the bond behaviour between the basalt fibre reinforced plastic (BFRP) bar and the engineered cementitious composite (ECC), pullout tests were performed in this paper to study the effects of the bar diameter, the embedded length, the cover thickness, and the properties of matrix materials on the bond performance. The test results indicate that the bond strength is generally controlled by the shear resistance of the BFRP bar surface layer for most of the specimens with pullout failure. For the specimens with a cover thickness of 5.5 mm, splitting failure occurred. The bond strength between the BFRP bar and cementitious matrix decreases with an increase in the bar diameter, and the specimen with a shorter embedment length achieves a higher bond strength. A linear equation can be used to describe the relationship between the average bond strength and the embedment length. The bond strength increases with the increase in cover thickness; however, this increase can be neglected when the ECC cover thickness exceeds 20 mm. The addition of PVA fibres decreases the damage and enhances the bond performances between the bar and the matrix.