GFRP筋与C15混凝土之间黏结强度的试验研究

基于12个拉拔试件的黏结试验,对GFRP筋与C15混凝土之间的黏结滑移特性、受力过程、破坏形态、破坏机理、黏结强度以及锚固长度等进行了研究.结果表明:GFRP筋试件的黏结应力下降到其黏结强度的8%~13%后,出现规律性的波动,而相应钢筋试件的黏结应力下降到20%~30%后基本保持不变;GFRP筋与C15混凝土之间的黏结强度较低,6.35 mm直径的GFRP筋,其黏结强度比相应的钢筋低8%,9.5 mm直径的GFRP筋,其黏结强度则比相应的钢筋低37%;GFRP筋试件的黏结应力达到黏结强度时,GFRP筋的滑移值为3~5 mm,而相应钢筋的滑移值为1~2 mm.文中还提出了GFRP筋与C15混凝土之间黏结强度以及GFRP筋锚固长度的设计建议.

Experimental studies on bond strength between GFRP rebar and concrete C15

Experimental studies were performed on 12 pull-out specimens to investigate the bond-slip characteristics,loading process,failure mode,failure mechanism,bond strength,and anchorage length of GFRP rebar in concrete C15.The result shows that the bond stress of GFRP rebar specimens fluctuates within a range of 3-4 MPa when it decreases to 8%?13% of its bond strength,however,the bond stress of normal steel rebar keeps invariable when it decreases to 20%?30% of its bond strength.The bond strength of GFRP rebar in concrete C15 is relatively low.Taking GFRP rebar with diameter 6.35 mm and 9.5 mm as examples,the corresponding bond strengths of GFRP rebar are 8% and 37% lower than those of normal steel rebar with similar diameters respectively.When the bond strength of GFRP rebar is reached,the slippage of GFPR rebar is 3?5 mm,but the value is 1?2 mm for the normal steel rebar.Finally,some suggestions for design about rational bond strength between GFRP rebar and concrete C15 and anchorage length of GFRP were made.