Based on experiments under short-term and long-term loads,studies on failure patterns,prestressing loss,ultimate stress of tendons,bending capacity,short-term and long-term deflections of new-type prestressed steel-concrete composite beams with prestressed concrete slabs and prestressed steel beams are studied in detail,and the corresponding design suggestions are systematically put forward.

Application and study on prestressed composite plate girders are presented in this article and its development in the future is pointed out as well.

The experimental results of prestressed composite box beams, including deformation, cracking distribution, section strain, failure mode and the mechanism under pure torsion are analyzed in detail.

Application and study on the prestressed conposite beam

It introduces the group structure of steel-concrete,elaborates the design methods of twisted prestressing force steel-concrete group piles,analyses its advantages and using scopes so as to promote the application and development of twisted prestressing force steel-concrete group piles.