Effects of variable curing temperatures on autogenous deformation of blended cement concretes

- Autogenous shrinkage under variable temperature curing investigated.
- Concretes with blended cement (fly ash) tested.
- Prominent expansive behavior found in high temperature curing.
- Expansion could not be linked to fly ash content.
- Different curing paths likely result in different thermal coefficient developments.

Shrinkage tests have been performed on blended Portland cement based early-age concrete with different w/c ratios, undergoing variable temperature curing. Results showed presence of induced non-negligible autogenous swelling which could mitigate part of the stresses related to shrinkage at very young concrete age. Recorded swelling was higher at higher curing temperatures and longer duration, especially pronounced for the low w/c mix. The swelling continued for several days after the temperature stabilized. Although not investigated directly, evidence to the nonlinear nature of the thermal expansion coefficient in young concrete has also been provided.

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