Title: Application of Super Workable Concrete to Construction of a 20-Story Building

Author(s): S. Kuroiwa, Y. Matsuoka, M. Hayakawa, and T. Shindoh

Publication: Symposium Paper

Volume: 140

Issue:

Appears on pages(s): 147-162

Keywords: compressive strength; cores; deformability; durability; slump; mix proportioning; multistory buildings; quality control; strength; reinforced concrete; segregation; workability; Materials Research

DOI: 10.14359/3909

Date: 9/1/1993

Abstract:
A super-workable concrete, which has excellent deformability and resistance to segregation and can be filled into heavily reinforced formwork without vibrators, was developed. This new type of concrete is made not only with the general materials for concrete such as ordinary portland cement, aggregates, water, and air-entraining water-reducing agent, but also with blast-furnace slag, fly ash, superplasticizer, and a newly developed viscosity agent. When the slump of this super-workable concrete is tested, diameter of the flow is more than 60 cm. Since the super-workable concrete has excellent durability as well as superior filling ability, it should be a proper concrete for projects under severe conditions. The super-workable concrete was employed in the construction work of a 20-story building. It was placed in the center-core from the basement to the third floor. The building was designed as a hybrid structure, in which the reinforced concrete core was surrounded by the steel structures. The specified design strength of the concrete was 480 kgf/cm 3 (47.1MPa). The greatest nominal diameter of deformed bars was 51 mm, and they were very congested. The super-workable concrete was produced in ready mixed concrete plants near the construction site, and 1500 m of the super-workable concrete was placed successfully. Through this project it was confirmed that the super-workable concrete can be supplied from general ready mixed concrete plants with practical care of quality control in materials.