비인장 강연선을 사용한 접합부 일체형 PC 보-기둥 시스템의 휨성능 평가

Abstract

In this study, a new moment-resisting precast concrete beam and column joint system was developed mainly for the use in underground parking lot in multi-residential building. It has attempted to devise connection details of the joint which will improve workability and provide effective stress transfer mechanism in the region of connection. The characteristics of the joint system is that the upper main reinforcements pass through the flanks of the column and the two pairs of the untensioned wire strands penetrate through the pre-scribed holes located at the upper and lower centers of the PC column.

For the evaluation of the performance of this new joint system, two types of the specimens were tested. The first one is to investigate the behavior of beams reinforced by deformed bars and untensioned strands in combination. The reinforcement ratio of the wire strand to the deformend bar was selected as the test parameter. The test results showed that the flexural capacities of all five specimens were sufficient. However when the untensioned strand reinforcement ratio is exceed 43%, the deflection increased considerably. Secondly the behavior of this joint system under the negative bending moment was investigated. Two specimens differentiated by the type of the penetrating reinforcement (deformed bars or wire strands) were tested. The results showed that the both specimens have sufficient flexural capacities and the deflection and ductility was similar to each other.

The study concluded that the new PC beam-column joint system has the structural performance satisfying the requirements,only when the reinforcement ratio of the wire strand is limited.