Study on the Bond-slip Performance and Load-transfer Mechanism of Bonded Rebars System
|Keywords||bonded rebars load transfer mechanism bond-slip constitutive relationship critical embedment length finite element analysis|
The chemically bonded rebar technique which is the topic of this research, as a means of post-installed fastenings technology is extensively applied in engineering. This technique can be showed by the following steps: first, drill a hole in the concrete base material; then, put the adhesive in the hole; then, insert the rebar into the hole; finally, the rebar is fastened by the bond of adhesive-rebar-interface and adhesive-concrete-interface.Currently, most of the research of chemically bonded rebar technique is taken the project application as the target, but the research of bond mechanics is deficient. In the practice, the examinations on the quality of the bonded rebar are limited to the ultimate carrying capacity. While there are not definite rules to the control of the bond-slide of the bonded rebar under the limit state of serviceability, that is, there is little study on the bond-slide of the chemically bonded rebar. In the practical engineering the bonded rebar is widely used in flexural member or comprehensive-flexural member, but the research is focused on the pull-out test. Chemically bonded rebar technique that is widely applied in engineering is urgently needed system thoroughly study.In this paper, the bonded rebars systems of steel tube and confined concrete block and unconfined concrete block are studied by the FE analysis based on the ANSYS program considering slip of interface. According to the analysis results, the load transfer mechanism of bonded rebars failed on steel-adhesive interface and failed on combination interface are understood.Also, the bonded rebars system of concrete beam with adhesive reinforcement is studied. Finally, the design and calculation formulas in bear capacity limit condition and normal limit condition of the bonded rebars system are formed.