SURFACE DISCOLORATION OF CONCRETE FLATWORK

LABORATORY STUDIES OF MOTTLING DISCOLORATION OF HORIZONTAL CONCRETE SLABS ARE DESCRIBED, SHOWING THAT DISCOLORATION IS INCREASED BY HARD TROWLING, BY USE OF CALCIUM CHLORIDE ADMIXTURES, OR BY POOR CURING OF THE SLABS. LOCAL DISCOLORATION CAN ALSO BE CAUSED BY NON-UNIFORM CURING CONDITIONS. AVOIDING THE USE OF CALCIUM CHLORIDE IN HARD- TROWELED FLATWORK WOULD ELIMINATE MUCH FLATWORK DISCOLORATION. IF CALCIUM CHLORIDE IS NECESSARY, CURING PROCEDURES RECOMMENDED TO MINIMIZE LOCAL DISCOLORATION ARE WATER PONDING OR USE OF SPRAYED MEMBRANE CURING COMPOUNDS. THE EFFECT OF CALCIUM CHLORIDE IS DEPENDENT ON THE ALKALI CONTENT OF THE CEMENT. IMMEDIATE AND THOROUGH WASHING OF THE CONCRETE SURFACE WITH WATER SEEMS THE EASIEST WAY OF "ERASING" DISCOLORATION. SPECIAL CHEMICAL TREATMENTS TO ERASE DISCOLORATION ARE OF ADDITIONAL BENEFIT. /PCA/

• Authors:
  • Greening, N R
  • Landgren, R
• Publication Date: 0

Media Info

• Serial:
  • Portland Cement Assoc R & D Lab Bull
  • Issue Number: 0

Subject/Index Terms

• TRT Terms: Alkali; Calcium chloride; Color; Concrete; Concrete curing; Laboratory studies; Membrane curing; Slabs; Washing
• Uncontrolled Terms: Discoloration
• Old TRIS Terms: Alkalies; Troweling
• Subject Areas: Highways; Maintenance and Preservation; Materials;

Filing Info

• Accession Number: 00213638
• Record Type: Publication
• Source Agency: Portland Cement Association
• Report/Paper Numbers: No 203
• Files: TRIS
• Created Date: Jun 1 1970 12:00AM