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)
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Corporate Authors:
Battelle Columbus Laboratories
505 King Avenue
Columbus, OH United States 43201Federal 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
- TRT Terms: Air entrainment; Calcium hydroxide; Chlorides; Concrete; Freeze thaw durability; Glass beads; Polymers; Sealing compounds; Slump test; Sodium chloride; Strength of materials
- Uncontrolled Terms: Concrete strength; Degradation
- Old TRIS Terms: Beads; Internally sealed concrete
- Subject Areas: Highways; Materials; I32: Concrete;
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