To study the bond behavior between the ribbed steel bars and sleeve constrained grouting material

pull-out tests were conducted on 45 specimens. The failure modes

ultimate bearing capacity and ultimate average bond strength were studied. The influences of bar diameter

anchorage length and sleeve dimension on the ultimate average bond strength were discussed. Bond-slip constitutive relations between the ribbed steel bars and grout constrained by sleeve were fitted. Equations were proposed for calculating the characteristic bond strengths and their corresponding slip value. Critical anchorage lengths

at which length bar broke or yielded and bar-grout slippage occurred at the same time

were calculated. The test results showed that with the increase of the bar diameter

the ultimate bearing capacity increased

and the ultimate average bond strength increased as a whole. With the increase of anchorage length

the ultimate bearing capacity increased

but the ultimate average bond strength decreased. In the range from 13.78% to 18.51%

the increase of steel content had little positive effect on the average bond strength. Because no coarse aggregate is contained in the grout

the slip value corresponding to the ultimate average bonding strength when the steel bar was anchored in grout was greater than that when the steel bar was anchored in concrete. Based on the energy analysis of the bond slip curve

it concluded that as the diameter and anchorage length of the bar increased

the brittleness coefficient of the specimen decreased generally

indicating the increase of the specimen’s ductility. Due to the confinement of the sleeve

the critical anchorage length decreased greatly.