Tensile behaviour of strain-hardening cement-based composites (SHCC) with steel reinforcing bars

Abstract

Strain-hardening, cement-based composites (SHCC) are a group of fibre-reinforced construction materials developed specifically to exhibit pronounced quasi-ductile behaviour and high strain capacity under tensile loading. In structural applications, SH CC are often used in combination with steel reinforcement. The article at hand presents an extensive experimental investigation carried out to analyse the load-bearing behaviour of R/SHCC subject to tensile loading. It includes material characterisation as well as uniaxial tension tests of slab elements with different reinforcement ratios and differing steel bar arrangements. It was shown that the production particularities of large specimens and their size influenced the mechanical performance of the SHCC, including its cracking behaviour, thus leading to a significant reduction of tensile strain capacity of structural elements in comparison with test results on small size specimens. The interaction with steel reinforcement, on the other hand, was found to facilitate multiple cracking and enhance tensile strain capacity during the stage of elastic steel deformations. However, a mutual dependency of SHCC fracture localisation and local plastic deformations of steel bars could be observed in the yielding stage of the steel reinforcement. The experimental results are discussed with respect to their implications for constitutive modelling under consideration of the individual behaviours of SHCC and steel bars as well as their bond interaction.