Title:
Application of Super Workable Concrete to Reinforced Concreted Structures With Difficult Construction Conditions
Author(s):
N. Miura, N. Takeda, R. Chikamatsu, and S. Sogo
Publication:
Symposium Paper
Volume:
140
Issue:
Appears on pages(s):
163-186
Keywords:
durability; flowability;, mix proportioning; placing; quality control; reinforced concrete; segregation; viscosity; workability; Materials Research
DOI:
10.14359/3787
Date:
9/1/1993
Abstract:
In Japan, a new super-workable concrete, which has higher flowability and filling capacity, has attracted attention as being effective in rationalization of concrete execution. It can be applied for simplifying placing work while securing high quality of reinforced concrete structures. Especially in case of heavily reinforced structures, it is highly applicable because of its excellent filling capacity or lower consolidation effort. For several years, the authors have studied improvements of workability of some special concretes, such as anti-washout underwater concrete, expansive grouting concrete for inverted placement, and ultra high-strength in-site concrete, and have consequently succeeded in developing super-workable concrete, suitable for rapid placing or perfect filling without consolidation. The authors also have established a new evaluating method for segregation resistance of mortar and aggregate, that is useful to design mix proportion, or keep high quality of super-workable concrete in site. Recently, opportunities to apply super-workable concrete to several actual structures with difficult construction conditions have arisen. One is the LNG (liquefied nitrogen gas) in-ground storage tank, which has much complicated reinforcement at the junction of base mat and side wall, another is a tall, thin reinforced concrete wall, which must be placed from upper point, 6 to 8 m in height. This paper describes the basic properties of super-workable concrete, the new method of quality control, and a summary of applications to reinforced concrete structures mentioned.