Early-Age Shrinkage of CEM I and Fly Ash Combinations Using a New Linear Test Method

Early-age shrinkage is a potential concern particularly due to the increase in use of new generations of concretes with new materials being developed for sustainability. Early-age shrinkage of concrete occurs while it is still in a semi fluid or plastic state. This can lead to cracks on the surface which in turn can lead to further durability concerns. It is evident that a lack of associated data and guidance on early-age shrinkage of concretes using these cement combinations prevents us from a complete understanding of the mechanism. The research reported in this paper utilised a new linear test method to measure the early-age shrinkage of pastes, mortars and concrete using CEM I and fly ash based combinations (II/A-V, II/B-V and IV/B) over a range of w/c ratios (0.4, 0.5 and 0.6). Normalization analysis was carried out to compare early-age shrinkage behaviour of concretes with different cement combinations at particular design strengths of 20, 40 and 60 N/mm2.