Direct assessment of tensile stress-crack opening behavior of Strain Hardening Cementitious Composites (SHCC)

The process of designing Strain Hardening Cementitious Composites (SHCC) is driven by the need to achieve certain performance parameters in tension. These are typically the pseudo-strain hardening behavior and the ability to develop multiple cracks. The assessment of the tensile load-deformation of these materials is therefore of great importance and is frequently carried out by characterizing the material tensile stress-strain behavior. In this paper an alternative approach to evaluate the tensile performance of SHCC is investigated. The behavior of the material in tension is studied at the level of a single crack and the tensile performance is evaluated in terms of the tensile stress-crack opening behavior. The experimental procedure and test setup used are discussed. The derived tensile stress-crack opening behavior is utilized to analyze and compare the influence of various composite parameters on the resulting tensile behavior. The deformations occurring during tensile loading are furthermore examined using a digital image analysis technique to gain detailed insight into the crack formation, propagation and opening phases.The authors thank the Portuguese National Science Foundation for the financial support, through grant SFRH/BD/36515/2007, funded by POPH-QREN, the Social European Fund and the MCTES, and DTU-Byg for their support of the work as part of this project