CONCRETE SEALERS


 

GENERAL

Concrete sealers for use in protecting concrete from chloride intrusion shall meet the requirements of applicable Iowa Department of Transportation Specifications. Sealers generating a shiny surface are listed in the Appendix A. They are intended for use only on bridge substructure areas such as pier tops and abutments. Sealers that do not affect surface texture are shown in the Appendix B. The sealers listed in the Appendix B can be applied to the bridge decks and the bridge substructure areas. The high molecular weight methacrylate (HMWM) primers/resins listed in the Appendix C can be applied to concrete bridge decks to bond and seal cracks.

 

ACCEPTANCE

Acceptance of concrete sealers for use on the Department of Transportation projects will be on the basis of manufacturer and brand name approval. Approved manufacturers and brands of concrete sealers are listed in the Materials Approved Products Listing Enterprise (MAPLE) as the Appendixes A and B for different applications.

 

MANUFACTURER & BRAND NAME APPROVAL

To obtain approval of a concrete sealer under the Appendixes A and B, manufacturer shall submit the following items to the Office of Construction and Materials in Ames, Iowa:

 

1. Product identification including brand name and product number;

2. Complete manufacturer recommendations of usage including coverage rate;

3. Current Safety Data Sheet (SDS);

4. If available, independent test data showing the effectiveness of the sealer in preventing chloride intrusion; and

5. A sample consisting of at least 1 quart of sealer.

 

The laboratory evaluation will consist of testing in accordance with AASHTO T 259: "Resistance of Concrete to Chloride Ion Penetration," except a C-3 mix shall be used. For a sealer used only on non-traffic surface area, sandblasting prior to applying sealer shall be omitted. For a sealer that can be used on traffic and non-traffic areas, the sandblasting shall be done before applying sealer.

 

The T 259 test result reported by the AASHTO National Transportation Product Evaluation Program (NTPEP) may be acceptable for approval review.

 

The chloride content of the treated concrete at the 1/16 in. to 1/2 in. depth shall not exceed 10 percent of the control concrete at the same depth.

 

Approval of a concrete sealer may be withdrawn because of deficient monitor test results; product changes made after original approval, or unsatisfactory field performance.

 

APPROVAL OF HIGH MOLECULAR WEIGHT METHACRYLATE

High molecular weight methacrylate (HMWM) primer/resin is a penetrant for bonding and sealing cracks in concrete. The accepted HMWM primer/resin shall contain at least 90% of solids by weight, and conform to the following requirements:

 

  1. Viscosity: Less than 25 cps when measured according to ASTM D2849
  2. Density: Greater than 8.4 lb./gal
  3. Flash point: Greater than 180F
  4. Vapor pressure: Less than 1.0 mm Hg @ 77F (ASTM D323)
  5. Gel time: Greater than 40 minutes
  6. Bond strength: Greater than 1000 psi (ASTM C882)

 

Approval of HMWM will be based on manufacturer providing independent laboratory test report to prove the product meets the above requirements. The manufacturer shall also include the following information on the container for the HMWM: The name of the manufacturer, the brand name of the product and the date of manufacture.

 

The sand used to maintain friction shall be a commercial quality dry 8/20 blast sand or other recommended by the HMWM manufacturer.

 

CERTIFICATION

Manufacturer shall file a certification statement at the beginning of each calendar year stating that the material supplied during that year is identical with the formulation previously tested and approved by the Office of Construction and Materials.

 

MONITOR SAMPLING & TESTING

The Office of Construction and Materials may sample and test concrete sealers to verify compliance with specifications.