Automatization of the verification of bonded and unbonded prestressed concrete beam, according to the Brazilian and French code specifications

Resumo

This paper presents a suggestion for the automatization of the procedures for design of bonded and unbonded prestressed concrete flexural members, according to the Brazilian (NBR 6118:2007) and French (Règles BPEL 91) code specifications. Is increasing the use of prestressing in concrete structures, mainly due to its many constructive advantages, reduction in crack incidence and decrease in section dimentions with the efficient use of higher resistance materials. The structural analysis is made by a numerical model that uses a hybrid type finite element for plane frames, considering geometric nonlinearity, cyclic loading and composite construction. In the computational algorithm implemented are considered full, partial and limited prestressing situations and checked, in each case, the Limit State of Decompression, the Limit State of Cracking, the Ultimate Limit State and the final act of prestressing. Finally, two examples are presented that compare design situations according to the Brazilian and French code specifications.