Comparison of numerical predictions for early-age creep

Creep at early ages significantly affects the volumetric deformation of cementitious materials. Efficient modelling of early-age creep is a challenging task, mainly due to continuously evolving material properties (hydration) and other phenomena (e.g. autogenous shrinkage) taking place in parallel. Various methods were introduced during the past decades to achieve a successful prediction. However, few comparisons between different methods are available until now. This study re-examines different numerical predictions for creep of cement pastes before 28 days. The investigated predicting methods include the recently proposed incremental rheology model [1], fictitious time (age) model [2] and solidification theory [3–5]. To compare the performance of these predictions, experimental creep results of cement pastes with water to cement ratio of 0.35 were used. Creep results under separate loading/unloading cycles were used to calibrate the parameters in the different methods, while creep results under sequential loading were used to validate their predictions. The advantages and disadvantages of each method are discussed. This study provides an assessment of the different methods and clarifies their requirements