Estudo comparativo entre fundações radier de concreto armado e protendido para edificações em alvenaria estrutural

Abstract

The radier foundation is a shallow foundation with little consideration in Brazil, on the other hand, this foundation is commonly the first option to be evaluated in several countries. Thus, there is little dissemination of the subject in Brazil, as well as the lack of current standards that provide sufficient parameters to properly size a radiator. In this sense, basic concepts related to the slab with soil interaction, the methodologies used for modeling and dimensioning are being presented in this work. The objective of this work is to elaborate a comparative case study of radier foundations in reinforced concrete and prestressed concrete, under the action of linear loads, for a building in structural masonry, disregarding the execution cost. With the help of the structural analysis software SAP2000, a 16 cm thick slab (in reinforced and prestressed concrete) was designed using a grid analogy, on an elastic base, simulating a residential building with four (4) floors. The case study involved the design of a reinforced concrete slab (RCA) with 25 MPa Fck and two prestressed concrete slabs (RCPI and RCPII) both with 30 MPa Fck and the use of straight cable in the center of the slab. The comparison parameters were the consumption of steel, concrete and the respective material costs. The results showed that the RCPI had lower passive steel consumption, about 99,99 % in relation to the RCA, because the prestressing provided favorable compressive stresses for the analyzed structure. However, compared to the RCA slab, the prestressing has a 21.82% higher cost due to the value for acquiring tendons cable.