Title:
Quality Control of 55 MPA Concrete
for Collins Place Project, Melbourne
Australia
Author(s):
K. W. Day
Publication:
Concrete International
Volume:
3
Issue:
3
Appears on pages(s):
17-24
Keywords:
cement content; high strength concretes;
histograms; laboratories; mix proportioning; quality
control; standard deviation; tests; variability.
DOI:
Date:
3/1/1981
Abstract:
The paper covers the results of operating an advanced system of quality control over a 3-year period of 55 MPa (800 psi) concrete supplied to a twin tower 4-story office building. The test results are analyzed with respect to variability, normality of distribution, testing error, and disagreement between testing laboratories. An account is given of the sources and magnitudes of the factors causing variability, including hot weather concreting using ice for cooling, The paper concludes that it is practicable to produce concrete of this strength at quite low variability over an extended period but that testing techniques and in terlaboratory disagreements tend to cause more problems than the actual concrete. [Author]