DOWEL BARS & DOWEL BAR BASKET ASSEMBLIES
This IM covers the requirements to supply load transfer dowels and dowel assemblies. Dowel assemblies/load transfer dowels shall meet the requirements in standard specification 4151 and standard road plan PV-101.
Approved sources of dowel bar basket assemblies and load transfer dowels can be found in the Materials Approved Products Listing Enterprise (MAPLE).
For manufacturers who are also epoxy coaters, prior to furnishing dowel bar basket assemblies/load transfer dowels on a certification basis, meet the approval requirements in Appendix A of this IM.
For manufacturers who are not also epoxy coaters, prior to furnishing dowel bar basket assemblies/load transfer dowels on a certification basis, meet the following requirements:
1. A request shall be submitted to Central Construction and Materials Office in Ames, Iowa detailing the location of the manufacturing plant and any distribution center(s). Shop drawing shall be submitted with the request letter.
2. Sources of epoxy steel that would be handled by the company and supplied to Iowa DOT projects.
3. Quality control procedures, meeting the minimum requirements outlined below, the company has established to ensure material identity (as to heat numbers and inventory control) from the time the material arrives from a mill or a source, through the fabricating process, shipment and record retention to satisfy IM 107 Buy America.
4. Bond Breaker shall be tested per AASHTO T253 test procedure for pullout resistance. The testing would need to be performed by an independent lab at the fabricators cost. The acceptable pull out resistance is 2500 Ibs or less.
5. An example of certification documents that the company will furnish for Iowa DOT projects meeting the requirements in IM 451.03B.
Upon satisfactory review of this application, satisfactory test results and satisfactory inspection of the facilities for compliance with quality control procedures, the company will be placed on the approved list.
The fabricators shall supply Iowa DOT updated QC plan, shop drawing, pull out test results per AASHTO T253 at the end of even years to continue staying on the approved list.
Prior to delivery to project site, the entire assembly shall be dipped in a bond breaker holding tank meeting the requirements of standard specification 4151.02 and the following:
Approved Bond Breaker or Solvent
1. TectyL 506*
· *TectyL 506 is a solvent/cutback corrosion preventive compound made by Daubert chemical company of Chicago, Ill.
· Is formulated to be used as supplied ( continuous stirring is generally not required)
· TectyL 506 cannot be thinned.
· Recommended ambient temperature for TectyL 506 is between 50° and 95° F at the time of application.
· TectyL 506 cannot be allowed to freeze. It should be stored (in the winter months) at temperatures over 50°.
· TectyL 506 can be spray or dip applied.
· Sample frequency 1.0 sample per fabricator/year. Additional samples may be secured for testing and verification.
2. Bradley Coating Group (BCG 6116 DSMA)
· Bradley Coating is a bond breaker.
· Bradley Coating is a corrosion preventative compound.
· Storage and application at room temperature between 50 and 95° F.
· Mild agitation is necessary prior to application.
· BCG 6116 DSMA can be thinned with either/or one of the following solvents to maintain the recommended liquid viscosity:
a. Tert-butyl acetate (TBA)
b. Mineral spirit
c. Methyl acetate (MA)
· Once the solvents evaporate, the dry film is left for protection.
The certification of compliance shall be signed by a designated or responsible company representative and shall be stated as follows:
The materials itemized in this shipment are certified to be in compliance with the applicable ASTM Standards and the Iowa Department of Transportation Standard Specifications, IMs and meet the Buy America requirements as described in IM 107 for all steel, iron products and coatings.
Authorized Signature & Date
A copy of this document is required for each shipment to a project and shall be provided to the Project Engineer responsible for project administration.
Acceptance is based on approved source and certification. One verification sample per year per source is required at the project site.