NEW DEVELOPMENT FOR HIGH QUALITY CONCRETE WITH
31st Our World in Concrete and Structures (OWICs) - 2006
K. Iriya*, Technical Institute of Obayashi.Corporation, Japan
R. Chikamatsu, Technical Institute of Obayashi.Corporation, Japan
N. Takeda, Technical Institute of Obayashi.Corporation, Japan
S. Sogo, Technical Institute of Obayashi.Corporation, Japan
pozzolan, sulfate acid, control of unit water weight, expert system, construction procedure
Concrete has been ordinarily used as one of structural materials, however, it
is now adopted for several extended fields, such as sulfate acid attack circumstance
so on. The sulfate acid resistance cement which has been described consists of
Ordinary Portland Cement, Silica fume, Fly ash and Blast furnace slag, which
converts portlandite to silicate minerals. This type of cement is not used for only
structural massive concrete but also repairing surface of deteriorated wall.
The quality of concrete with such extended functions is assured by severe
quality control and inspection upon mixing and construction. Especially controlling
unit weight of water, by means of adjusting surface water content of aggregate, is
very important in mixing plants. Excessive water induces rising water cement ratio
and decreases required functions.
Suitable construction procedure is also very important in construction sites.
Unsuitable construction procedure induces several problems as generating defective
zone such as cold joints, honey comb defects, and cracking and it may deteriorate
the extended functions.
Sulfate acid resistance concrete has been developed to apply concrete for its
severe condition. The high reliable concrete producing system can adjust the amount
of surface water of aggregate with high accuracy by immerging aggregate into
mixing water. Navigating system on a constructing procedure is effective in order to
avoid making defective zone due to mistakes in construction planning. These new
development can be reliable for high quality concrete with extended functions.