CONCRETE LIBRARY OF JSCE NO. 18, DECEMBER 1991
CHANGE IN MICRO-STRUCTURE OF CONCRETE DUE TO CARBONATION
(Reprint from Transaction of JSCE, Vol.420/V-13,Aug.1990)
Tatsuhiko Saeki
Hiroyuki Ohga
Shigeyoshi Nagataki
SYNOPSIS
Micro-structure of concrete is changed due to carbonation and the change in
micro-structure affects properties of concrete. An accelerated carbonation test
and a wet-dry test are performed to investigate the change in micro-structure of
mortar considering water-cement ratio and initial curing condition. The depth of
carbonation, the amount of calcium hydroxide and calcium carbonate, pore volume,
pore size distribution, and the weight of mortar are measured.
The change in pore volume and pore size distribution due to carbonation depends
on water-cement ratio and initial curing period. Pore volume in the carbonated
portion is decreased in the case of the continuous carbonation test. Denseness
of structure induced by carbonation affects a subsequent carbonation process. T.Saeki is a research associate of Department of Civil Engineering at Niigata
University, Niigata, Japan. He received his master of engineering degree from
Tokyo Institute of Technology in 1989. His research has been on carbonation of
concrete. He is a member of JSCE and JCI.
H.Ohga is a research associate of Institute of Industrial Science at the
University of Tokyo, Tokyo, Japan. He received his doctor of engineering degree
from Tokyo Institute of Technology in 1991. His recent research has 1xxn1 on
properties of concrete containing mineral admixtures, and durability of
concrete. He is a member of ACI, JSCE and JCI.
S.Nagataki is a professor of Department of Civil Engineering at Tokyo Institute
of Technology, Tokyo, Japan. He received his doctor of engineering degree from
the University of Tokyo in 1966. His research interests cover properties of high
strength concrete, effective use of industrial by-products in concrete,
durability of concrete. He received a fellow of ACI in 1986. He is a member of
ACI, ASCE, JCI, JSMS and RILEM.
__Z_