This IM covers mechanical splices.  The requirements for mechanical splices can be found in standard specification 4151.  Approved suppliers of mechanical splices for reinforcing bars can be found in the Materials Approved Products Listing Enterprise (MAPLE).



Prior to furnishing mechanical splices to a project the supplier or fabricator shall request approval by submitting the following items:


1.     A written application for approval shall be submitted to the Office of Construction and Materials in Ames, Iowa, and shall contain the following items.


a.     Source of steel

b.     Grade of steel

c.      Grade of couplers

d.     Name of fabricator

e.     Epoxy powder brand name and coater’s name, if applicable


2.     Quality control procedures that the company has established to ensure material identity (heat number, source, etc.)


3.     A typical example of certification documents that the company will furnish to Iowa DOT projects.


4.     Test reports from independent / certified lab showing test compliance with the intended requirements.


5.     Submit three different samples of three different sizes for testing (coated and uncoated)




·        The steel mill, fabricator or supplier shall furnish a letter of compliance with a certification statement indicating the couplers meet the ASTM and Iowa DOT specification requirements.  The letter shall indicate the project number, county and contractor’s name.

·        If epoxy coated couplers are used, the certification statement shall also include the name of the epoxy coating company and powder brand.

·        The steel mill, fabricator or supplier shall furnish an identification list, invoice or bill of lading for each shipment to each project.  It shall show the project and quantity of couplers shipped to the project.

·        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


·        The signed mill test reports used in the fabrication of the couplers shall include the chemical and mechanical properties, ASTM designation, grade and type for each heat. 

·        The signed mill test reports/certification shall also include a statement indicating that the steel meets the requirements of IM 107, Group 1, Buy America.



Acceptance of mechanical splices shall be on the basis of certification from an approved source and certification as described above.