A detailed investigation was carried out on 30-year-old concrete specimens made with ordinary portland cement (OPC), high early-strength portland cement (HES), Type B slag cement (SCB), and alumina cement (AL). In each specimen, steel bars were embedded at cover depths of 20, 40, and 70 mm. Mineralogy and microstructure of mortar portions at the inner and outer regions, aggregate-matrix and steel-matrix interfaces, and deposits in the voids of the mortar portions were investigated. It is concluded from the results that the microstructure of concrete at the outer region for AL and SCB becomes denser compared with the inner region. For AL, the inner region is relatively more porous, and a porous steel-concrete interface is also found. Other conclusions on the ingress of SO 3 and Cl, leaching of Ca, and healing of voids in concrete are also summarized herein.
|Number of pages||10|
|Journal||ACI Materials Journal|
|Publication status||Published - Jan 1 2004|
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Building and Construction
- Materials Science(all)