Expansion of Curbstone Concrete Imitated Granite
By H. Matsushita and Y. Kawabata
Concrete Journal, Vol.43, No.12, Dec. 2005
- Synopsis
- Recently, the failure of curbstone concrete have been reported in Fukuoka, Yamaguchi and Okayama Prefecture. The concrete have been characterized by expansion and cracking after several years of service in environments exposed in water. The concrete consists of white cement, limestone and copper slag and it has been manufactured at elevated temperatures for early shipment. As a result, examination identified delayed ettringite formation (DEF) as the damaging mechanism. SEM-EDX analysis identified that ettringite accumulated around limestone in damaged concrete. Therefore, this study concluded that expansion of curbstone concrete have been due to delayed ettringite formation because of steam curing above 80 deg C and the reaction between calcite and monosulfate.
- Keywords:
- expansion, white portland cement, limestone, copper slag, steam curing, ettringite, DEF
