Title:
Concrete Incorporating Supplementary Cementing Materials: Effect of Curing on Compressive Strength and Resistance to Chloride-Ion Penetration
Author(s):
M. H. Zhang, A. Bilodeau, V. M. Malhotra, Kwang Soo Kim, and Jin-Choon Kim
Publication:
Materials Journal
Volume:
96
Issue:
2
Appears on pages(s):
181-189
Keywords:
chlorides; compressive strength; curing; fly ash; silica fume; slag
DOI:
10.14359/443
Date:
3/1/1999
Abstract:
This paper presents the results of an investigation dealing with the effects of a curing method on the compressive strength and the resistance to chloride-ion penetration of concrete incorporating supplementary cementing materials. The concrete was either cured under wet burlap for seven days followed by exposure to the laboratory air, or was cured using three different curing compounds. The effect of the water-cement ratio (w/c) and the type of supplementary cementing materials including fly ash, silica fume, and ground granulated blast-furnace slag were evaluated. The compressive strength of the concrete was determined at 7, 28, and 91 days, and the resistance of the concrete to the chloride-ion penetration was determined at 28 and 91 days. For the portland cement concrete with a w/c ratio of 0.32, the compressive strength and the resistance of the concrete to the penetration of chloride ions were not affected significantly by the curing conditions. The portland cement concrete with w/c ratios of 0.55 and 0.76 and cured under wet burlap had significantly higher resistance to the penetration of chloride-ions and higher compressive strength than those cured using Compound I. For the portland cement concrete with a water-to-cementitious materials ratio of 0.32 and incorporating silica fume and slag, the compressive strength of the cores taken at 7 and 28 days and the resistance of the concrete to the penetration of chloride-ions were not affected significantly by the curing conditions. However, at 91 days, the cores taken from the concrete cured under wet burlap had higher compressive strength than those cured using Compound I. For the concrete with a water-to- cementitious materials ratio of 0.32 and incorporating ASTM Class F or Class C fly ash, the compressive strength of the cores taken at 7 days was not affected by the curing conditions. However, at 28 and 91 days, the concrete cured under wet burlap showed higher compressive strengths than that cured using Compound I. For the concrete incorporating ASTM Class F fly ash, the resistance to the penetration of chloride-ions was affected by the method of curing, with the concrete cured under wet burlap showing superior resistance to that cured using Compound I. For concrete incorporating ASTM Class C fly ash, the resistance to the penetration of chloride-ions was not affected significantly by the method of curing. In general, the type of curing compounds used did not affect either the compressive strength or the resistance of the concrete to chloride-ion penetration significantly.