Use of pore solution analysis in design for concrete durability

Pore solution analysis of hardened cement-based materials has been in increasing use over the last 30 years to determine the ionic composition of the pore fluid at various ages and after exposure to various temperature regimes. In addition, it has been used to evaluate the potential for results of chemical interaction with external solutions or with other concrete materials (such as alkali-reactive aggregates). Once related to physical durability test data, knowledge of the pore solution composition in combination with the nature of the solid phases present can be used to predict the potential for future durability-related chemical interactions. This paper discusses three areas where the usefulness of pore solution analysis has been instrumental in increasing the understanding of concrete durability issues related to: (a) alkali binding as it affects alkali–silica reaction (ASR), (b) chloride-binding as it affects reinforcement corrosion resistance, and (c) delayed ettringite formation (DEF).