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 are typically penetrating epoxy sealers applied to the gutter line, curb, and barrier rail. The sealers listed in Appendix C are typically silanes applied to the bridge deck surface.
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, B, and C for different applications.
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". 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 comparison between control and treated slabs by an independent laboratory will be acceptable for approval.
For Appendix B, 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. For Appendix C, the chloride content of the treated concrete at the 1/16 in. to 1/2 in. depth shall not exceed 50 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Approval of a concrete sealer may be withdrawn because of deficient monitor test results; product changes made after original approval, or unsatisfactory field performance.
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 Construction and Materials Bureau.
The Construction and Materials Bureau may sample and test concrete sealers to verify compliance with specifications.