A novel durability design approach for new cementitious materials: Modelling chloride ingress in strain-hardening cement-based composites

To fully utilise the advantageous durability properties of new cementitious materials such as fibre-reinforced Strain-Hardening Cement-based Composites (SHCC), a performance-based durability design approach is required. For crack-free ordinary concrete first promising concepts exist, e.g. the DuraCrete model. However, the parameters of these models, which were quantified for ordinary concrete, cannot be applied to SHCC due to its significantly different composition. As multiple cracking with limited crack width under tensile load is a characteristic material property of SHCC, any durability model for this material furthermore has to consider the cracked state. In this paper a novel durability design approach is presented exemplary for chloride ingress in SHCC. The developed approach takes into account the limited availability of relevant data for new materials, which prevents a reliable stochastic quantification of model parameters. The DuraCrete ingress model was adapted for SHCC with the help of fuzzy-probability theory, which allows the quantification of parameters using expert knowledge even if the data basis is very limited. the engineering properties of the material including tensile strength and strain capacity (Kabele et al. 2006). The limited available data on chloride ingress in SHCC (Miyazato & Hiraishi 2005; Oh & Shin 2005) indicates that the water-binder ratio may have a more significant influence on the transport properties than in ordinary concrete, and that in the cracked state the material exhibits superior resistance to the ingress of corrosive media. More recently Sahmaran