August 14, 2001

Refer to: HAS-10/B89

Mr. Bijan Kasraie

Consolidated Tire Corporation

1430 W. Peachtree St., NE Suite 705

Atlanta, GA 30309

Dear Mr. Kasraie:

Late last year, Dr. Dean Alberson sent me information on some pendulum testing he 

had done on offset blocks produced by your company. These blocks are made from 

multiple plies of recycled tire tread laminated together through a patented process 

and intended for use with strong post, w-beam guardrail. Pendulum testing 

consisted of swinging an 820-kg pendulum through a vertical drop of 4 m into a 

fixed steel guardrail post with a short section of W-beam and your blocks attached. 

The posts failed at ground line and the blocks remained intact. However, because 

the blocks did not have a routing on the back face as did similar products, Dr. 

Alberson was advised that crash testing would be needed to verify the expected field 

performance of your block. Alternatively, he was told that if routing was added to 

the existing product, full-scale testing would not be mandatory. 

Mr. Richard Powers of my staff recently received Dr. Alberson’s July 19 letter that 

included a revised drawing with a route incorporated into the design and with 

dimensions that conform more closely to previously tested and/or accepted blocks. 

Please note, however, that - without full scale testing - the minimum depth of the 

block must be 150 mm rather than the 132 mm shown in the enclosed drawing 

(Enclosure 1). A block 200-mm deep would also be acceptable and is likely to 

perform better in service.

Based on the results of the pendulum tests run, your product may be considered 

acceptable for use on the National Highway System (NHS) when it conforms to the 

dimensions shown on Enclosure 1 (as modified above) and is composed of the same 

materials as the tested blocks. As with all other recycled blocks accepted for use on 

the NHS, FHWA acceptance is based solely on the reported impact performance in 

the pendulum test and is not intended to address the long-term performance or 

durability of the product. Since your block is the first laminated design we have 

seen, the effects of weathering in particular should be carefully monitored on initial 

field installations. 

Since your block is a proprietary product, its use on Federal-aid projects, except 

exempt, non-NHS projects, is subject to the conditions listed in Title 23, Code of 
Federal Regulations, Section 635.411, a copy of which is enclosed for your ready 

reference. If you have any questions, please call Mr. Powers at (202) 366-1320.

Sincerely yours,

(original signed by Frederick G. Wright, Jr.)

Frederick G. Wright, Jr.

Program Manager, Safety

2 Enclosures

Sec. 635.411 Material or product selection. 

(a) Federal funds shall not participate, directly or indirectly, in payment for any premium or royalty on 

any patented or proprietary material, specification, or process specifically set forth in the plans and 

specifications for a project, unless: 

(1) Such patented or proprietary item is purchased or obtained through competitive bidding with equally 

suitable unpatented items; or 

(2) The State highway agency certifies either that such patented or proprietary item is essential for 

synchronization with existing highway facilities, or that no equally suitable alternate exists; or 

(3) Such patented or proprietary item is used for research or for a distinctive type of construction on 

relatively short sections of road for experimental purposes. 

(b) When there is available for purchase more than one nonpatented, nonproprietary material, 

semifinished or finished article or product that will fulfill the requirements for an item of work of a 

project and these available materials or products are judged to be of satisfactory quality and equally 

acceptable on the basis of engineering analysis and the anticipated prices for the related item(s) of work 

are estimated to be approximately the same, the PS&E for the project shall either contain or include by 

reference the specifications for each such material or product that is considered acceptable for 

incorporation in the work. If the State highway agency wishes to substitute some other acceptable 

material or product for the material or product designated by the successful bidder or bid as the lowest 

alternate, and such substitution results in an increase in costs, there will not be Federal-aid participation in 

any increase in costs. 

(c) A State highway agency may require a specific material or product when there are other acceptable 

materials and products, when such specific choice is approved by the Division Administrator as being in 

the public interest. When the Division Administrator's approval is not obtained, the item will be 

nonparticipating unless bidding procedures are used that establish the unit price of each acceptable 

alternative. In this case Federal-aid participation will be based on the lowest price so established. 

(d) Appendix A sets forth the FHWA requirements regarding (1) the specification of alternative types of 

culvert pipes, and (2) the number and types of such alternatives which must be set forth in the 

specifications for various types of drainage installations. 

(e) Reference in specifications and on plans to single trade name materials will not be approved on 

Federal-aid contracts. 

ENCLOSURE 2