Characterization of cement paste by dynamic mechanical thermo-analysis. Part I: Operative conditions

The present study presents dynamic mechanical thermoanalysis (DMTA) of cement pastes and promotes the specificity of this non-destructive technique. Operative conditions and their impact on results are reviewed. A set of silicate rich cement pastes (HTS) vapour cured at 80 C for 48 h, is submitted to a very small sinusoidal torsion strain. Dynamic mechanical behaviour of the sample is studied within a [-150 degrees C, 226 degrees C] temperature range. A rate of temperature increase of 2 K min(-1) is fixed. The sinusoidal strain imposed has a frequency of 1 Hz in further tests. Different temperature paths are defined to characterize a sample: single run/double run and step run. Results show that DMTA is useful to characterize porosity, silicates hydration and silicates degradation. Moreover DMTA is able to check whether polymer is well dispersed in the cement matrix or not. (c) 2006 Elsevier Inc. All rights reserved.