Comparison of tensile and compressive creep of hydraulic concrete considering loading/unloading under unified test conditions

Abstract

In order to study the relationship between the magnitude of the tensile and compressive specific creep of concrete, and to compare the measured and predicted creep recovery based on the superposition principle. In this paper, combined with the concrete mix proportion of typical hydraulic engineering, creep tests of hydraulic concrete under loading/unloading with different loading ages (7, 28, and 60 days) are conducted under unified test conditions. Furthermore, the equivalent age theory is introduced to establish eight-parameter specific creep models of tension and compression considering the effect of temperature history, and an optimization algorithm is used to identify the parameters of the models. Finally, the recovery of specific creep under tensile and compressive different creep is discussed in detail based on the principle of superposition. The results show that the specific creep in tension is greater than that in compression in all three creep test groups, and the recovery of specific creep in tension and compression after unloading indicates that the predicted values of the recovery of specific creep obtained by superimposing compressive specific creep are in better agreement with the measured values.