Steel Fibre Reinforced Self-Compacting Concrete for Grid Foundations of Single Family Houses

This paper describes the preliminary studies carried out in the scope of an applied research project for the design and construction of Steel Fibre Reinforced Self-Compacting Concrete (SFRSCC) grid foundations for single-family houses. Adopting a constitutive model for the simulation of the post-cracking behaviour of fibre reinforced concrete, and modelling a complete typical single-family house by taking into account the soil-structure interaction, it was estimated the post cracking residual tensile strength for the SFRSCC to be developed. The aimed SFRSCC was prepared in a concrete mix plant, and standard specimens, ½ scale beam prototypes and a ¼ scale grid prototype were cast. To take into account, in the design context, the fibre distribution and orientation that can occur in grid foundations, core samples were extracted from distinct locations and depths in these beams, and the stress-crack width relationship, -w, was experimentally assessed. Based on the obtained -w curves, and using a cross-section layer model, the flexural capacity of the grid foundation was evaluated. The obtained results show the suitability of SFRSCC for this type of structures.

Nuno Alves, Joaquim Barros, Ângela Nunes, Lúcio Lourenço