Title: Mechanical Properties, and Freezing-and-Thawing Resistance of Non-Air-Entrained and Air-Entrained Condensed Silica-Fume Concrete Using ASTM Test C 666, Procedures A and B

Author(s): V. M. Malhotra

Publication: Symposium Paper

Volume: 91

Issue:

Appears on pages(s): 1069-1094

Keywords: air-entrained concretes; air entrainment; concretes; freeze-thaw durability; plasticizers; silica; water-cementitious ratio.

DOI: 10.14359/10113

Date: 2/1/1986

Abstract:
This report presents the results of a study dealing with the resistance to repeated cycles of freezing and thawing of non air-entrained and air-entrained condensed silica-fume concrete when tested in accordance with ASTM C 666, Procedures A and B. A total of twenty-two air-entrained and non air-entrained concrete mixtures, 0.06 m3 in size, were made. The water-to-(cement + silica fume) ratio (W/C+S) of the mixtures ranged from 0.40 to 0.60, and the percentages of cement replacement by condensed silica fume were 0, 5, 10, 15, and 30 per cent on a weight basis. Any loss in slump due to the use of condensed silica fume was compensated for by the use of a superplasticizer. A number of test cylinders were made for testing in compression at various ages, and test prisms were cast for determining their resistance to repeated cycles of freezing and thawing in accordance with ASTM C 666, Procedures A and B. Sawn sections of the test prisms were used for determining the air-void parameters of the hardened concrete. Based upon the analysis of the test data it is concluded that the use of non air-entrained condensed silica-fume concrete is not recommended when it is to be subjected to repeated cycles of freezing and thawing. Furthermore, the users of condensed silica fume are cautioned against using high percentages of the material as replacement for portland cement in concretes with W/C+S of the order 0.40 if these concretes are to be exposed to repeated cycles of freezing and thawing.