Unified modelling of the temperature effect on the autogenous deformations of cement-based materials

摘要

Temperature effects are of primary importance for designing concrete structures. Some of the early age temperature effects on the concrete behaviour can be accurately taken into consideration by well-known maturity functions. However, the effect of temperature on the autogenous deformations development is more complex, and results in contradictory evidence. This paper studies the influence of various isothermal curing temperatures from 10 degrees C to 30 degrees C on the autogenous deformations of concrete. Binary and ternary binders containing up to 30% of limestone filler and 70% of blast-furnace slag are studied. The amplitude of both the self-desiccation deformation and the early age swelling deformation are observed to decrease with increasing temperature, whatever the binder nature. Mechanisms for this observation are suggested, and a corresponding model is developed. The effect of the binder nature, age and temperature on the autogenous deformations is assessed with this model. Based on this new model, it is shown that the effect of temperature on the autogenous deformation development can be either beneficial or detrimental, depending on the nature of the binder.