Comportamento estrutural de pilares curtos em concreto de alta resistência

Abstract

High-strength concrete (HSC) has found an increase utilization in the last twenty years, in particular in the case of columns of high-rise buildings. In spite of the great advantages presented by this material, both resistance and ductility of HSC columns have been a matter of concern with respect to the safety of these structural elements. However, it is a well-known fact that such behavior can be improved by the use of transverse reinforcement. Although, several studies have demonstrated the smaller efficiency of the confinement in the case of HSC columns. As it can be concluded, the quantification of the resistance and ductility of HSC columns is of vital importance. Experimental studies represent an alternative for obtaining information about the structural behavior of HSC columns, in practice this alternative is limited (costs, necessary equipments, etc). On the other hand, the numeric simulation of theresistance and ductility can overcome these limitations. In this study, the numeric simulation of the resistance and ductility of HSC columns is implemented through of the computer program PILAR. It is shown that the crucial problem in the modeling of the structural behavior of columns is the selection of the stress-strain relationship for confined HSC. The results obtained from two confinement models, - the modified Fafitis and Shah model and the Razvi and Saatcioglu model -, are presented andvalidated against experimental results presented in the literature representing different geometries of the cross-section, rates of transverse and longitudinal reinforcement, transverse reinforcement arrangement, yield strength of the transverse reinforcement, and concrete compression strength.