Shrinkage and creep behavior of an alkali‐activated slag concrete

Abstract

In this paper, experimental results about the shrinkage and creep behavior of an alkali‐activated slag concrete (AAS‐concrete) are presented. The autogenous shrinkage of AAS‐concrete is pronounced at a relatively high water to binder ratio of 0.41. The ultimate value of autogenous shrinkage is determined to be higher than that of high‐strength concrete (HSC). The observed self‐desiccation at a later concrete age can be one of the reasons for the autogenous shrinkage. In a drying environment of 65% relative humidity AAS‐concrete exhibits a significantly higher total shrinkage compared to normal‐strength concrete composed of Portland cement. In the contrary to normal and HSC carbonation shrinkage must not be neglected for AAS‐concrete in the early concrete age. The sum of drying and carbonation shrinkage develops much more rapidly for AAS‐concrete in the first weeks after the beginning of drying. Based on the experimental results the shrinkage behavior of AAS‐concrete cannot be predicted by conventional models. The creep behavior of the AAS‐concrete was investigated under sealed and unsealed conditions. The creep coefficients for both conditions are higher than those calculated when using conventional models.

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