Dynamic mechanical thermo-analysis of Portland cement paste hydrated for 45 years

The effect of prolonged hydration of Portland cement paste on engineering behavior was investigated using dynamic mechanical thermo-analysis (DMTA) methods. Specimens ranged in age from 3 days to 45 years. Compacts of hydrated cement powders and normally hydrated paste specimens were tested. Age dependent nanostructural characteristics of C–S–H were shown to influence the mechanical response of cement paste. Evidence was provided to support the use of compacts as structural models for hydrated cement paste. Details of ageing effects on the DMTA parameters (storage modulus and internal friction) as a function of temperature and porosity are reported.