The influence of temperature on electrical conductivity measurements and maturity predictions in cementitious materials during hydration

Electrical property measurements are being increasingly used to assess the transport properties of building materials. While conductivity measurements have been extensively used, the combined dependence of electrical conductivity on measurement temperature and microstructural development (cement hydration) is often overlooked. In this paper the influence of temperature and microstructural development (i.e. hydration) are separated. Two cement paste mixtures are assessed at 283K, 296K, and 309K, and the conductivity response is analysed to differentiate the contribution of maturity (pore structure refinement due to hydration) and temperature (due to changing ionic mobility). The conductivity measurements are used to determine the activation energy of electrical conduction (i.e. temperature dependence of ion mobility) and hydration (i.e. temperature dependence of reaction rates). This workprovides an improved understanding of how temperature influences electrical measurements in cementitious systems at early ages, and can provide for an accurate interpretation of the electrical properties of the system. This information will enable improvements in the use of electrical measurements for quality control and quality assurance (QC/QA) testing.