INVESTIGATION OF DISCOLORATION OF CONCRETE SLABS
Brown discoloration of concrete slabs has been associated with an/or attributed to the use of plastic sheeting for curing or protecting concrete (among other possible causes). Previous research has been performed without yielding a thorough understanding of the mechanisms behind the problem, which has been known to occur in Wisconsin, northern Illinois, and Louisiana. This study was undertaken to ascertain the causes of buff/red surface color variations in concrete flatwork, experienced especially during periods of high relative humidity and high ambient temperature. The results indicate that: The variations may be attributed primarily to differences in curing and degree of hydration of the surface cement. The small amounts of ferrous iron in the cements and Class C fly ashes may make some discoloration almost inevitable on properly cured concrete surfaces. The problem may be mitigated by: delaying the curing; using selected curing compounds; and/or curing the surface for an extended period, possibly as long as ten days. It is recommended that further laboratory and site work be performed to evaluate the effects of different curing regimes.
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Corporate Authors:
5420 Old Orchard Road
Skokie, IL United States 60077 -
Authors:
- Miller, F M
- Powers, L J
- Taylor, P C
- Publication Date: 1999
Language
- English
Media Info
- Features: Figures; References; Tables;
- Pagination: 22 p.
Subject/Index Terms
- TRT Terms: Cement; Concrete; Concrete curing; Curing agents; Fly ash; Humidity; Hydration; Iron; Plastics; Temperature; Time periods
- Uncontrolled Terms: Discoloration
- Subject Areas: Highways; Materials; I32: Concrete;
Filing Info
- Accession Number: 00792168
- Record Type: Publication
- Report/Paper Numbers: PCA R&D Serial No. 2228
- Files: TRIS
- Created Date: May 4 2000 12:00AM