Creep of cement paste containing fly ash - An investigation using microindentation technique

Grid-microindentation tests were conducted to study the effect of fly ash content, water-binder ratio and capillary water on creep of cement paste. Cement paste specimens containing 0%, 20% and 40% fly ash (by weight of binder) were tested at 1, 3, 7, 28 and 90 days. It is found that the effect of fly ash content on creep depends on the age at loading. It is also noted that for a given loading age, the creep deformations increase with increase in water-binder ratio. Presence of capillary water is found to have an influence on creep of cement-fly ash paste system. Logarithmic fit for creep deformation, while overestimating the experimental values in the early stages, is in good agreement at later stages.