Title:
Diffusivity of Chlorides from Seawater Into High-Strength Lghtweight Concrete
Author(s):
Odd E. Gjorv, Kefeng Tan, and Min-Hong Zhang
Publication:
Materials Journal
Volume:
91
Issue:
5
Appears on pages(s):
447-452
Keywords:
chlorides; diffusivity; high-strength concrete; lightweight aggregates; lightweight concretes; seawater; tests; Materials Research
DOI:
10.14359/4061
Date:
9/1/1994
Abstract:
As part of a more comprehensive research program on high-strength lightweight concrete (50 to 100 MPa), test results on the diffusivity of chlorides from natural seawater are presented. The chloride diffusivity of the various concrete mixes was very low with effective diffusion coefficients typically varying from 2.7 to 5.6 x 10 -9 cm 2/sec. Of the various material parameters included in the test program, it was the presence of silica fume that had the most dominating effect on the diffusivity. Nine percent replacement of the cement by silica fume reduced the chloride diffusivity by a factor of about 5, while an increasing content of the total amount of cementitious materials from 440 to 660 kg/m 3 decreased the diffusivity by a factor of about 2. Five different types of lightweight aggregate with increasing particle densities from 1.07 to 1.44 g/cm 3 were used. The difference of the concretes with the least dense aggregate was about two times higher than those obtained with the most dense aggregate. Type of fine aggregate and maximum aggregate size only had a minor effect on the chloride diffusivity. The impact of the obtained chloride diffusivity on service life is also discussed.