PHYSICAL FACTORS INFLUENCING RESISTANCE OF CONCRETE TO DEICING AGENTS

STUDIES WERE MADE OF THE EFFECTS OF VARYING CONCRETE PRODUCTION METHODS UPON POTENTIALLY DURABLE CONCRETE. VARIATIONS IN THE SURFACE POROSITY, STRENGTH AND AIR VOID SYSTEM PRODUCED BY DIFFERING FINISHING TECHNIQUES WERE EVALUATED FOR TYPICAL AIR-ENTRAINED CONCRETES. LARGE AND SMALL SCALE SPECIMENS WERE CAST AND EFFECTS OF PERIOD AND TIME OF FINISHING, ENVIRONMENTAL CONDITIONS, AND ADDITIONS OF WATER DURING FINISHING WERE EVALUATED USING SURFACE SCALING TESTS, SURFACE TENSILE STRENGTH TESTS AND MICROSCOPICAL DETERMINATION OF SURFACE AIR VOID PARAMETERS. THE RESULTS INDICATED THAT THE SURFACE MORTAR AIR CONTENT IS LOWER THAN THE MORTAR AIR CONTENT WITHIN THE CONCRETE. BUT THE SPACING BETWEEN THE VOIDS IS AT LEAST AS SMALL AS THE VOID SPACING WITHIN THE CONCRETE. THUS THE EFFICIENCY OF THE AIR VOID SYSTEM AT THE SURFACE IS NOT AFFECTED BY THE LOWER AIR CONTENT. OVER-FINISHING AND ADDITIONS OF WATER DURING FINISHING GENERALLY HAD NO HARMFUL EFFECTS UPON THE SURFACE AIR VOID SYSTEM, BUT OVERFINISHING DID RESULT IN MORE SEVERE DETERIORATION IN SURFACE SCALING TESTS. THE ADDITION OF MODERATE AMOUNTS OF WATER TO THE SURFACE IMMEDIATELY AFTER CASTING, AND IMMEDIATE FINISHING, DID NOT RESULT IN SIGNIFICANT DECREASES IN SURFACE DURABILITY. COMBINATIONS OF PREMATURE FINISHING, HEAT AND WIND APPLICATIONS AND RETARDED CONCRETES DID NOT PRODUCE WEAKENED PLANE SCALING AND HAD DIFFERING EFFECTS UPON SURFACE TENSILE STRENGTH. THE SURFACE TENSILE STRENGTH DID NOT CORRELATE WELL WITH THE SURFACE SCALING RESISTANCE. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_27.pdf
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00775614
• Supplemental Notes:
  • Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved. No 27, 41 PP, 13 REF, 4 APP
• Authors:
  • Malisch, W R
  • Raecke, D A
  • Fischer, D M
  • Lott, J L
  • Kennedy, T W
  • Kesler, C E
• Publication Date: 1966

Media Info

• Media Type: Digital/other
• Serial:
  • NCHRP Report
  • Issue Number: 27
  • Publisher: Transportation Research Board
  • ISSN: 0077-5614

Subject/Index Terms

• TRT Terms: Air entrained concrete; Air voids; Concrete; Concrete finishing; Deicers (Equipment); Environmental impacts; Physical condition; Porosity; Production methods; Seal coats; Specimens; Strength of materials; Tensile strength; Testing; Time; Water
• Uncontrolled Terms: Deicers; Scaling
• Old TRIS Terms: Air voids content; Resistance
• Subject Areas: Construction; Environment; Highways; Maintenance and Preservation; Materials; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00212279
• Record Type: Publication
• Files: TRIS, TRB, ATRI
• Created Date: Nov 18 1994 12:00AM