Head of Construction Materials Section, Canada Centre for Mineral and Energy Technology, Mineral Sciences Laboratories, Ottawa,
This investigation was undertaken to develop data on the durability of non-air-entrained, air-entrained, and air-entrained superplasticized concrete when tested in accordance with the ASTM Test for Resistance of Concrete to Rapid Freezing and Thawing (C 666) Procedures A and B. A total of nineteen 0.06-m3 mixes were made with water-to-cement ratios ranging from 0.35 to 0.70. Apart from the control mixes, all other mixes were either air-entrained or air-entrained and superplasticized. A number of test prisms were cast and subjected to repeated cycles of freezing and thawing and air-void parameters of the hardened concrete were determined. The following conclusions were made from the test results.
1. Regardless of the test procedures used, the test prisms cast from non-air-entrained concrete disintegrated at less than 31 cycles. The only exceptions were the test prisms cast from concrete with a water-to-cement ratio of 0.35, which indicated satisfactory resistance to repeated cycles of freezing and thawing in test Procedure B, the durability factor after 300 cycles being greater than 90.
2. Regardless of the test procedure used, the concrete prisms cast from air-entrained concrete and air-entrained superplasticized concrete performed satisfactorily when subjected to repeated cycles of freezing and thawing. At the end of 300 cycles, the durability factors were greater than 90. This was in spite of the fact that the bubble spacing factor ¯L for air-entrained superplasticized concrete was, in some instances, greater than 0.20 mm.
Paper ID: CCA10219J