Title: Role of Expansive Admixtures in High-Performance Concrete

Author(s): C. Enyi and L. Huizhen

Publication: Symposium Paper

Volume: 149

Issue:

Appears on pages(s): 575-588

Keywords: admixtures; cracking (fracturing); deformation; drying shrinkage; fly ash; high-performance concretes; segregation; strength; workability; Materials Research

DOI: 10.14359/4099

Date: 10/1/1994

Abstract:
Besides high workability (high filling capacity and high resistance to segregation), little drying shrinkage and high resistance to cracking are important properties required for high-performance concrete. Addition of expansive admixture by appropriate proportion is an efficient way to compensate drying shrinkage for conventional concrete. By experimental investigations, it is confirmed that there is a very similar effect for high-performance concrete (HPC). But the effects of different types of expansive admixture for improving properties of high-performance concrete are various. As distinguished from using silica fume to produce HPC, fly ash is adopted in tests. It is found that appropriate amount of fly ash can not only avoid segregation, but also helps regulate unfavorable expansion of concrete caused by excessive content of expansive admixtures. Four types of expansive admixture are used in tests. Their effects on workability, deformation, and strength of HPC are discussed in this paper.