Design criteria for flat slabs with unbonded tendons

Abstract

This paper is the continuation of papers No. 177 and 187 previously published in ""Hormigón y Acero"". With this series presented in this magazine on the testing of a prestressed concrete slab with unbonded tendons is completed. The slab was 8,4 x 10,0 square meters and was supported by nine columns. The paper describes the results obtained in the failure test performed with an increasing distributed load applied on the four pannels of the slab. The failure was produced by punching at the central support. The measurements obtained during the loading process allowed the detailed description of the most characteristic phenomena observed. These experimental results have been compared to numerical analysis based on the finite element method. As a consequence of this study, some of the most remarkable aspects to be considered in the design of this kind of structures are presented. Special attentions is given to aspects showing lack of agreement between international recomendations.