Can the maturity concept be used to separate the autogenous shrinkage and thermal deformation of a cement paste at early age?

The influence of temperature on the autogenous shrinkage of cement paste has been studied using the maturity approach based on Arrhenius' law. Application of this law requires knowledge of the apparent activation energy, E-a, of cement. In this work, E-a has been determined by the "setting time method." The external volume change of cement paste was measured by hydrostatic weighing. In order to separate the thermal and autogenous deformations, the thermal dilation coefficient (TDC) was determined at both 20 and 30 degreesC. Investigations have shown that maturity can be used to predict autogenous shrinkage under isothermal and realistic conditions as long as temperatures remain between 10 and 40 degreesC. Outside of this temperature range, the calculated autogenous deformation and measured isothermal shrinkage are quite different and, as a result, autogenous shrinkage appears to be dependent on more than hydration advancement alone. (C) 2002 Elsevier Science Ltd. All rights reserved.