Impact of steel ductility on the structural behaviour and strength of RC slabs

Abstract

This thesis examines the effects of reinforcement ductility on the strength and ductility of reinforced concrete slabs. An extensive experimental program examining the ultimate strength, ductility and failure mode of one-way and two-way reinforced concrete slabs is described and the results are presented and analysed. A numerical finite element model is developed and calibrated using the experimental data. The model is described and shown to accurately simulate the collapse load behaviour of reinforced concrete slabs containing reinforcement of any ductility class, including Class L welded wire fabric. Parametric studies using the numerical model to assess the effects of reinforcement ductility on structural behaviour are also presented and recommendations are made on the minimum reinforcement ductility levels appropriate for use in suspended slabs. The experimental and numerical tests investigated slabs with different types of boundary conditions (simply supported and continuous one-way slabs, corner-supported single panel two slabs and edge-supported two-way slabs), support settlement, steel reinforcement ratio, steel uniform elongation (su), steel ultimate to yield stress ratio (fsu/fsy) and rectangularity aspect ratio in the two-way slabs. In total, thirty one slabs were tested. The one-way slabs included four simply supported slabs, seven continuous slabs, and five continuous slabs with support settlement. The two-way slabs included eleven square and rectangular corner-supported slabs and four rectangular edge-supported slabs. The one-way simply-supported slabs were 850mm in width, 100mm in depth and 2,500mm in length. The continuous one-way slabs were 850mm in width, 100mm in depth and 4,350mm in length. The continuous one-way slabs and subjected to support settlement were 850mm in width, 120mm in depth and 6,300mm in length. The square two-way slabs had an edge length of 2,400mm and a depth of 100mm and the rectangular two-way slabs had width of 2,400mm, a length of 3,600mm and a depth of 100mm.