Title:
Alkali-Silica Reaction-Induced Strains over Concrete Surface and Steel Bars in Concrete
Author(s):
Tarek Uddin Mohammed, Hidenori Hamada, and Toru Yamaji
Publication:
Materials Journal
Volume:
100
Issue:
2
Appears on pages(s):
133-142
Keywords:
alkali-silica reaction; expansion; steel; strain
DOI:
10.14359/12553
Date:
3/1/2003
Abstract:
A detailed experimental investigation was carried out to understand the alkali-silica reaction (ASR) induced strains over the concrete surface and embedded steel bars in concrete. For this study, prism specimens 250 x 250 x 600 mm were made with different layout of the reinforcements in concrete, that is, different restraint conditions. Additional NaOH was added to raise the total Na2O equivalent alkali content in concrete to 6 kg/m3. The specimens were submerged in seawater at 40 °C in a closed container. Lateral and longitudinal strains over the concrete surface and strains over the steel bars were measured. Crack maps over the specimens were also recorded periodically. In addition to the prism specimens, cylinder specimens 100 mm in diameter and 200 mm in length were also investigated for pulse velocity, compressive strength, and Young’s modulus. Based on the experimental data, ASR-induced expansion process and strain induced over the concrete surface and steel bars with the variation of restraint conditions provided by the steel bars in concrete are summarized.