Title: Influence of Curing Conditions on Shrinkage of Blended Cements Containing Various Amounts of Slag

Author(s): Mladenka Saric-Coric and Pierre-Claude Aitcin

Publication: Materials Journal

Volume: 100

Issue: 6

Appears on pages(s): 477-484

Keywords: blended cement; concrete; curing; shrinkage; swelling

DOI: 10.14359/12954

Date: 11/1/2003

Abstract:
The influence of curing conditions on the shrinkage of ternary blended cements containing 20, 30, 50, and 80% slag and 5% silica fume has been studied on a series of concrete specimens having a water-binder ratio (w/b) of 0.35 on small specimens 100 x 100 x 400 mm. Two slags were used to evaluate the importance of their Blaine fineness (430 and 540 m2/kg). The shrinkage behaviors of a Type 10 Canadian cement and a blended cement containing 5% silica fume were also studied as references. When cured under water since their placing, the concretes made with the ternary blended cements swelled less than those made with the pure portland cement, but more than the 5% silica fume concrete. When cured under sealed conditions, concretes containing slag present a much higher autogenous shrinkage than pure portland cement concretes. The higher the amount of slag, the higher the autogenous shrinkage at 1 year. When the concretes made with slag-blended cements received an early water curing lasting 7 days, however, these concretes, after 1 year, present a smaller total shrinkage (autogenous + drying) than the pure portland cement concrete cured under the same conditions. This research emphasizes the importance of a very early water curing when making concretes with ternary slag blended cements to lower the long-term total shrinkage.