Title:
Air Void Stability, Part I: Influence of Silica Fume and Other Parameters
Author(s):
Michel Pigeon, Patrick Plante, Michel Pigeon, Patrick Plante, and Michel Plante
Publication:
Materials Journal
Volume:
86
Issue:
5
Appears on pages(s):
482-490
Keywords:
air entrained concretes; air-entraining agents; air entrainment; fresh concretes; plasticizers; silica fume; stability; Materials Reseach
DOI:
10.14359/2077
Date:
9/1/1989
Abstract:
Thirty concrete mixes were prepared to analyze the influenced of silica fume and other parameters on the stability of the air void system during mixing and agitation. For each mix, four sets of samples were cast over a period of 90 min after initial water-cement contact. The modified point count method (ASTM C 457) was used to determine the characteristics of the air void system on each set of samples. Results indicate that silica fume and type of mixing have little influence on the production and stability of the air void system, but that superplasticizers can cause a significant increase of the value of the spacing factor. This influence of superplasticizers was found to vary quite significantly with the characteristics of the cement and also with the type of superplasticizer and air-entraining agent. Results also show that it is difficult to estimate correctly the value of the spacing factor from that of the air content of the fresh concrete.