Title:
Stabilized Air Void System in Superplasticized Concrete
Author(s):
K. Baekmark, H. Hansen, and J. Reichart
Publication:
Symposium Paper
Volume:
144
Issue:
Appears on pages(s):
177-190
Keywords:
air-entraining agents; air entrainment; durability; slump; specific surface; stability; superplasticizers; water-reducing agents; Materials Research
DOI:
10.14359/4397
Date:
3/1/1994
Abstract:
The fact that a stable air-void system in concrete enhances its durability is well documented today. In Denmark, for example, all concrete to be used for exterior components is air-entrained. The main problem is to insure the stability of the air-void system in the concrete, independent of mixing time, transportation, consistency, fines content, and type of plasticizer or superplasticizer. A new type of air-entrainer has been developed that provides excellent performance in concrete containing a melamine sulfonate-type of superplasticizer. The concrete has a slump of more than 150 mm, and even after 60 min of transportation and pumping, the air-void content and air-void structure are still satisfactory. The air-entrainer is a combination of special surfactants chosen after a long series of tests. Carrying out such a range of tests within the short time available was possible only because of newly developed testing equipment, which made it possible to measure air content and air-void system parameters within 30 min while the concrete was still fresh. Results of the testing, in accordance with ASTM C 457, are presented.