The effects of tapered sleeve in improving the achorage bond of reinforcement bar

Abstract

This research examine on the effectiveness of tapered sleeve connector in providing confinement effect to embedded reinforcement bar. The objectives of the investigation are to study the bond mechanism of grouted sleeve connector and to study the effects of confinement provided by the grouted sleeve connector. Two different configurations (welded bar sleeve and tapered sleeve) of sleeve connector were used in this study. Various sleeve diameters were used in this research to study their effects on the bond mechanism. The bond failure progression inside the grouted sleeve connector was observed visually as halved welded steel bar connector and tapered head connector were used. The experimental works consisted two phases where phase I was the testing of plain grouted sleeve. Phase II involved the testing steel fibre reinforced grout sleeve. Steel fibres of 0%, 0.5%, 0.75% and 1.0% were introduced to the connector in a way so the grout inside the connector will exhibit post-cracking behaviour. Pull-out tests were carried out and it was observed that the performance of tapered sleeve was better than welded bar sleeve due to higher confinement level. The provision of sufficient confinement stress able to delay the development of splitting cracks. The test result showed that welded bar sleeve was governed by splitting failure mode, whereas tapered sleeve failed in pull-out failure mode.