INTERNAL SEALING OF CONCRETE WITH DEGRADABLE POLYMER BEADS

This report describes the selection, screening, fabrication, and testing of solid polymer beads and capsules for use as internal sealants which degrade insitu in a wet concrete mix without the application of external heat. Known sealant material candidates such as linseed oil or silane were combined with carrier/release agents such as bentonite, ammonium stearate, or degradable polymers and tested in Ca(OH)2 or NaC1 solutions or neat cement bars for release of sealant. Materials showing release and having suitable fabrication characteristics were fabricated into beads. Beads with and without degradable polymer coatings were incorporated into actual concrete mixes for evaluating air entrainment, slump, strength, freeze thaw, and chloride penetration characteristics. Beads which gave an acceptable combination of properties were used to prepare a field mix in a redi-mix truck, which did not give the same reduction of chloride penetration observed in laboratory mixes. Although this work has shown that chloride penetration can be reduced two-fold or more by 4 v/o (volume percent) beads, other properties are sacrificed and even at this loading the concrete is not fully sealed. The use of internal sealants which are themselves compatible with the concrete is recommended to obtain maximum sealing efficiency with minimal effect on strength and othe rproperties. (FHWA)

  • Corporate Authors:

    Battelle Columbus Laboratories

    505 King Avenue
    Columbus, OH  United States  43201

    Federal Highway Administration

    Research, Development and Technology
    6300 Georgetown Pike
    McLean, VA  United States  22101
  • Authors:
    • Kistler, C W
    • Benton, B F
  • Publication Date: 1983

Media Info

  • Pagination: 78 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00387778
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-RD-83-091 Final Rpt.
  • Contract Numbers: DTFH G1-80-C-0025
  • Files: TRIS, USDOT
  • Created Date: Sep 28 1984 12:00AM