BOND BEHAVIOR OF GLASS FIBER REINFORCED POLYMER RIBBED REBARS WIRH SPECIALLY DESIGNED RIB GEOMETRIES

摘要

In the study, 96 pullout specimens were tested based on the Canadian Standards Associationrn(CSA) criteria to study the bond behavior of specially machined Glass Fiber ReinforcedrnPolymer (GFRP) ribbed rebars to concrete. Conventional reinforcing rebars were also studiedrnfor comparison. Each rebar was embedded in a 150 mm concrete cube, and the embeddedrnlength was four times the rebar diameter. The variables were the rebar type, rebar diameter,rnrebar rib height, and rib spacing. For each rebar, the failure mode, the average bond strengthrnand the bond-slip relationship curves were analyzed. Test results indicated that the bondrnstrength of GFRP rebars was about 35 percent lower than that of steel rebars. The bondrnstrength and bond-slip resistance of the specially machined rebars varied with the rebar type,rnrebar diameter, rib height, and rib spacing. Using the results, design recommendations werernmade concerning optimum rib geometries of ribbed rebars with superior bond-sliprncharacteristics, which concluded that the optimal rib spacing of ribbed rebars is 1 times thernrebar diameter, and the optimal rib height is 6 percent of the rebar diameter.