Title:
Comparative Study of Latex-Modified Concretes and Normal Concretes Subjected to Freezing and Thawing in the Presence of a Deicer Salt Solution
Author(s):
Daniel Bordeleau, Michel Pigeon, and Numkumar Banthia
Publication:
Materials Journal
Volume:
89
Issue:
6
Appears on pages(s):
547-553
Keywords:
air entrainment; concretes; deicers; freeze-thaw durability; latex; water-cement ratio; Materials Research
DOI:
10.14359/4001
Date:
11/1/1992
Abstract:
Freezing and thawing tests in the presence of a 2.5 percent NaCl solution were carried out on normal concretes and styrene butadiene rubber (SBR) latex concretes in accordance with ASTM C 672. Latex-modified concretes were prepared with 7.5 and 15 percent of solid polymer-to-cement ratio. All mixtures were made with a Canadian Type 10 portland cement. Three different water-cement ratios were used: 0.30, 0.35, and 0.40. For a given latex content and water- cement ratio, a minimum of three mixtures with air-void spacing factors ranging from 100 to 1000 were prepared. Normal concretes were moist-cured for 3 days while SBR concretes were cured for only 1 day using wet burlap. Deterioration of the concrete surfaces was evaluated by measuring the mass of scaled-off particles and by visual rating. The results indicate that SBR in concrete improves very significantly the resistance of the concrete surface to freezing and thawing in the presence of deicer salts. This improvement depends on the quantity of SBR, the air-void spacing factor, and the water-cement ratio. Only 2 of the 9 standard mixtures, but 12 out of the 17 modified concrete mixtures, had mass losses lower than 1 kg/m 2 at 100 cycles. The results also show that a conventional concrete with a good air-void spacing factor and a low water- cement ratio can be almost as resistant to salt scaling as latex-modified concrete.