Effect of fly ash and repeated loading on diffusion coefficient in chloride migration test

✍ Scribed by Wu-man Zhang; Heng-jing Ba; Shang-jiang Chen

• Book ID: 104017403
• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 599 KB
• Volume: 25
• Category: Article
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2010.11.016

✦ Synopsis

In this paper, the effect of fly ash (FA) on the diffusion coefficient of concrete subjected to repeated loading was examined. Portland cement was replaced by three percentages (20%, 30% and 40%) of FA. Five repeated loading were applied to concrete specimens using a WHY series full automatic testing machine. The maximum loadings were 40% and 80% of the axial cylinder compressive strength (f 0 c ). The diffusion coefficients were calculated from the steady state in the chloride migration test by using the Nernst-Planck equation. The results indicate that the use of FA causes a lower cylinder compressive strength and a higher diffusion coefficient at the age of 28 d. This trend increases with increasing of FA replacement. Compared with nonload specimens, five repeated loadings at 40% or 80% f 0 c increases the diffusion coefficients (D 28 ) for all mixes investigated in this study. The impacts of FA and repeated loading on the service life prediction from Life-365 model are discussed.