Title:
Application of an Air-Entraining and Plasticizing Admixture to High-Strength Concrete
Author(s):
Norio Marushima, Kenji Kuroha, and Kuniyiki Tomatsuri
Publication:
Symposium Paper
Volume:
121
Issue:
Appears on pages(s):
599-618
Keywords:
admixtures; air-entraining agents; concrete durability; dispersants; high-strength concretes; plasticizers; precast concrete; quality assurance; reinforced concrete; workability; General
DOI:
10.14359/3758
Date:
11/1/1990
Abstract:
High-strength concrete tends to mean small water-cement rations, implying poor workability. This tendency becomes more pronounced when much higher strength is required, and conventional concreting processes cannot sufficiently guarantee high-quality work. In current construction work, therefore, maximum use has been made of precast concrete (guaranteeing quality and minimizing the need for concrete cast in situ) and a new high-performance, air-entraining, and plasticizing admixture has been used for the necessary in situ concrete. The concrete prepared in this way exhibited a mix strength of 55 MPa at best. This value, in itself, is by no means high, but meaningful efforts to establish methods of concreting that insure still greater strength have been made. This construction work has demonstrated that combining the reinforced concrete (RC) layer method (which uses a large proportion of precast members) with high-strength concrete obtained from mixing with the new high-performance, air-entraining, plasticizing admixture is an extremely effective way to secure quality structures. Since this admixture is a novel product, the physical properties of the resulting concrete have been thoroughly checked to supplement the results of laboratory experiments and preliminary field tests.