Analysis of Prestressing Loss on Construction of External Prestressed Wooden Buildings

Wooden buildings which has a long history, is one of the earliest forms of building structures by mankind.The structure form and construction method of are different from the common prestressed structure,therefore,the prestressing loss caused by the external prestressed structures is different from that of the common prestressed structure.It is an effective method to reduce the large deflection of large-span wooden structure by external prestress method.Through the real model test of the external prestress tension at scale of 1:2,and after long-term observing on parabolic wooden beam of external prestress with initial pretension force,we can quantitatively analyse the effections of prestressing loss of prestressed rebar due to the creep of wood.At the same time,this paper gives the deflection calculation formula during the term of test.The conclusion obtained is useful to designers.