Title:
Give It a Week: 7 Days of Initial Curing
Author(s):
M. N. Haque
Publication:
Concrete International
Volume:
20
Issue:
9
Appears on pages(s):
45-48
Keywords:
blast furnace slag; compressive strength; curing; fly ash;
high-strength concretes; humidity; hydration; silica fume;
DOI:
Date:
9/1/1998
Abstract:
Seven high-strength concretes with total cementitious contents of 450 kg/m3 were made. The concretes consisted of plain cement and 10 and 30 percent fly ash, ground granulated blast furnace slag, and condensed silica fume. The specimens were exposed to 10 different curing regimes consisting of fog room curing, 45 percent relative humidity, and oven drying at 110 C. The results suggest that a complete cessation in hydration at an early age with no provision of subsequent curing and with subsequent curing, results in about a 40 and 20 percent loss in strength, respectively, which can otherwise be achieved by adequate curing of the concretes. A 7-day initial curing of all the concretes considerably improved the quality of the cover concrete and its compressive strength. For the concretes cured for an initial period of 7 days, the subsequent curing or complete lack thereof was neither critical nor important with regard to the development of the compressive strength and the 2-hour water absorption of the cover.