긴장재의 배치에 의한 부분 PT구조의 경제성 검토

Post-tension (PT) slabs are generally classified by the tendon lay-out as concentrated type, distributed type, and combination type, whose deflection depends on the tendon lay-out and its amount. Finite element analysis were performed to analyze the efficiency of deflection control by primary parameters; distribution types of tendons and ratios of prestressed reinforcement. Based on analysis results, economic efficiency was estimated considering both material and construction cost. In this study, the increase of construction cost and the efficiency of deflection control by partial PT method with top anchorage were also included. The results of this study indicate that the partial PT method with top anchorage is very efficient for deflection control and can save the amount of tendon by applying tendons in a part of span required due to large deflection anticipated. The application of the partial PT method with top anchorage increase the construction cost about 6% compared to that in RC structure, which is considered to be reasonable cost for the important deflection control.