Reforço em lajes de concreto armado

Abstract

This work discusses the tests results of solid reinforced concrete slabs, featuring a strengthened upper surface. Five solid reinforced concrete slabs were cast and tested, measuring 415 cm x 415 cm x 7 cm. The main variables were two types of common pathologies in this kind of structure, namely, concrete strength and reinforcement deficiencies. Reference slab L1 was tested up to failure and the others were tested until a determined load, after which they were strengthened and retested up to failure. All slabs experienced flexural failure and in the slabs that were originally minimally reinforced, the application of the strengthening layer raised the failure load by up to 30% in relation to a similar unstrengthen slab, regardless of the original concrete strength. In all tests with strengthened slabs there were neither traces of bond failure nor evidence of loss of bond between the old concrete and the concrete of the strengthening layer.