POLYMER GROUTS AND ADHESIVE ANCHORS
Polymer grouts shall and adhesive anchors meet the requirements of applicable Iowa Department of Transportation Specifications. Approval of polymer grouts and adhesive anchors may be withdrawn because of deficient monitor test results; product changes made after original approval, or unsatisfactory field performance.
Acceptance of polymer grouts and adhesive anchors for use on Department of Transportation projects will be on the basis of manufacturer and brand name approval. Approved manufacturers and brand names of polymer grouts and adhesive anchors are listed in the Materials Approved Products Listing Enterprise (MAPLE) as Appendixes A, B, C, and D for different types of applications. The ASTM C 881 requirements outlined below are applied to the epoxy-based adhesives only. Other type adhesives will be evaluated and approved based on the equivalent performance.
1. Product identification including brand name and product number
2. Complete manufacturer recommendations for usage
3. A current Safety Data Sheet (SDS)
4. A sample consisting of enough material for three pullout tests with dispensing tool.
Appendix A contains pourable polymer grouts intended for vertical installations or angled installations less than 45° from vertical. Mechanical mixing is required to blend the material to uniform consistency. The adhesives listed on Appendix A shall also be compliant with ASTM C881, Type IV or V.
Appendix B lists viscous polymer grouts intended for horizontal installations. Mechanical mixing is required to blend the material to uniform consistency. The adhesives listed on Appendix B shall also meet the requirements of ASTM C881, Type IV or V, Grade 2 or 3 (except gel time).
The laboratory evaluation for both Appendix A and B will consist of bonding a No. 5 reinforcing bar in a 4-inch deep, 3/4-inch diameter hole in a concrete specimen and performing a pullout load test. After a seven-day cure at laboratory temperature, the test specimen shall have a 9,000-pound minimum load. The reported pullout load shall be the average of two tests.
The test result of confined tensile (pull-out) test of single anchor, specified and reported by the AASHTO National Transportation Product Evaluation Program (NTPEP), may be acceptable for approval review. The test specimen shall have a minimum 1,300 psi of pull-out strength.
Appendix C contains polymer grouts for dowel bar installation. Either an encapsulated chemical anchor system or a pressure-injectable system with mechanical proportioning and mixing shall be required to blend the material to uniform consistency.
To obtain approval for products under Appendix C, the laboratory evaluation will consist of bonding a No. 5 reinforcing bar in a 4-inch deep, 3/4-inch diameter hole in a concrete specimen and performing a pullout load test. The test specimen shall develop a minimum pullout load of 40 pounds in one hour, and at least 10,000 pounds of pullout strength in 24 hours. The specimens will be kept and tested at laboratory temperature. Two tests are required to obtain the average of each pullout load. A product meeting this strength requirement for Appendix C may also be placed on Appendixes A and B, provided that it meets the ASTM C881 Type and Grade requirements specified in the previous section.
Appendix C also lists approved adhesives with high pullout strength. In addition to the above pullout test requirement, manufacturer shall provide the test result indicating that adhesive listed shall be able to generate a minimum ultimate-pullout load of 25,000 pounds for a 5/8 in.-diameter steel rod embedded 5-5/8 in. in concrete with a minimum compressive strength of 4,000 psi.
Appendix D lists approved adhesives used as chemical anchors. Approval of adhesive anchors shall be based on tension (pull-out) and shear tests in accordance with ASTM E488. Tests shall be performed by an independent certified laboratory. Manufacturers shall provide characteristic strength design values or allowable loads for design purpose. The characteristic strength design values provided shall be derived based on statistical evaluation of the experimental strength test data. The allowable loads recommended shall not exceed 1/4 of ultimate loads.
To obtain the approval of adhesive chemical anchors, manufacturers shall also provide independent test results to show that their products meet the creep criteria of ICC-ES AC 308 or AC 58 (International Code Council, Evaluation Service).
The adhesive anchors listed in Appendix D shall not be used in sustained tensile-load overhead applications in highway projects.
The 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.
The Office of Construction and Materials may sample and test polymer grouts to verify compliance with specifications.