HIGH PERFORMANCE ADMIXTURES FOR SELF-COMPACTING CONCRETE : MECHANISM AND APPLICATION IN CHINA BUILDING
In this paper, the basic functional mechanism of high performance admixture (HPA) in SCC is discussed combining with the development of modern concrete admixture. Major applications of JM-SCC in China construction including hydraulic hydropower, transportation and industrial building, such as the Three Gorges Dam, the Gongboxia Hydropower Station, the Nanjing-Hangzhou Express Way, etc. are presented.
Self-compacting concrete. Development, present use and future
Self-compacting concrete was first developed in 1988 in order to achieve durable concrete structures. Since then, various investigations have been carried out and the concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making it a standard concrete. Recommendations and manuals for self-compacting concrete were also established.
EFFECTS OF ANTIWASHOUT ADMIXTURES ON PROPERTIES OF HARDENED CONCRETE
The effects of incorporating two commonly used types of antiwashout admixtures, welan gum and hydroxypropyl methyl cellulose, on properties of hardened concrete are investigated for mixes with water-cement ratios ranging between 0.30 and 0.60. Compressive strength, flexural strength, and modulus of elasticity development up to 3 months, as well as bond with reinforcing steel, apparent chloride ion permeability, and pore size distribution are evaluated.