Predicting non-evaporable water loss of cement paste at elevated temperature

摘要

A research programme was conducted to predict non-evaporable water loss in hardened cement paste at elevated temperature. Existing models underestimate non-evaporable water loss for blended cement paste as the models are expressed as a function of mass of anhydrous cement. Thermogravimetric analysis and differential thermogravimetry were used to determine the decomposition profile of amorphous hydrates and portlandite. Analysis of test results showed that the decomposition profile of amorphous hydrates and portlandite was independent of mix design, degree of hydration and inclusion of pozzolana. An equation which addresses limitations in existing models is proposed to predict non-evaporable water loss at elevated temperature based on the volumetric ratio and decomposition profile of amorphous hydrates and portlandite in hardened cement paste. Both experimental and predicted non-evaporable mass losses were in accordance.