An experimental study on prestressed composite beams with corrugated web

The demands for longer span and reduction of story height have greatly increased as building structures become much larger and higher in recent years. Although the development of flexural members for reducing story height or making long span has been studied by many researchers and engineers, there is still a lack of efficient systems that meet these two demands simultaneously. This study aimed at developing a new composite beam system suitable for long span and reduction of story height, and proposed a prestressed composite beam with corrugated web. It has great resistance against non-symmetric construction load due to its strong out-of-plane shear strength with relatively small member height as well as good constructability and economic efficiency by removing/minimizing form work. The corrugated webs also make accordion effect introducing larger effective prestressing force to top and bottom flanges, which causes larger upward camber reducing the member deflection. A flexural behavior model is proposed for this composite member utilizing the concepts of effective moment of inertia coefficient(?f) and effective area coefficient(?a) to account for accordion effect before composition. Five full-scale specimens with primary test parameters of web sectional shapes, number of drape points, and the use of shear connectors were tested to understand their flexural behavior and to verify the performance of the proposed method. The experimental test results showed that the proposed prestressed composite beam had greater flexural strength and stiffness than the ordinary non-prestressed composite beam, and that the flexural behavior model proposed in this study provided reasonable estimation of their flexural behavior.