Bond-slip behavior between basalt fiber reinforced plastic bars and recycled aggregate concrete

Corrosion of steel bars is one of the key factors undermining the stability of reinforced concrete structures. Internal defects of the recycled aggregates used in recycled aggregate concrete (RAC) decrease the durability of concrete structures, and may accelerate steel corrosion. The use of corrosion-resistant materials as substitutes for steel bars in RAC may solve this problem. Basalt fiber reinforced Polymer (BFRP) is a corrosion-resistant material. This study assessed the bonding properties between BFRP bars and RAC using pull-out tests. The following five factors were considered: RAC strength grade, the RAC cover thickness, bond anchorage length of BFRP bars, diameter of BFRP bars, and replacement rate of the recycled concrete aggregate (RCA). The effects of these factors on failure mode, bond strength, and the bond-slip curve were assessed. Finally, the bond-slip relationship between BFRP bars and RAC was established by improving the mBPE model, which can describe the bond behavior between BFRP bars and RAC with satisfactory accuracy.