September 18, 2002 

 HSA-10/B49C 

Mr. Chad Heimbecker 

Director, Product Development 

Bryson Products, Inc. 

224 Nazareth Pike, Suite 22 

Bethlehem, PA 18020 

Dear Mr. Heimbecker: 

In your July 25 letter to Mr. Richard Powers of my staff, you requested formal 

acceptance of a revised plastic guardrail offset block named RE-BLOCK:IV and 

provided a copy of a Texas Transportation Institute report dated July 19, 2002, and 

entitled “Pendulum Testing and Evaluation of the Central Fabricator’s Guardrail 

Blockout.” 

The RE-BLOCK:IV, as shown in the enclosure, is a hollow 4 inch x 8 inch block 

with three horizontal stabilizer bars and a depth of 14 inches for use with W-beam 

and 21-5/8 inches for use with Thrie-beam. Its material composition is similar to the 

original RE-BLOCK, using an average blend of 50 per cent HDPE and 50 per cent 

LDPE. Additionally, successful pendulum tests were conducted on a block made 

with 100 per cent HDPE and one made with 80 per cent HDPE and 20 per cent 

cross-linked HDPE/PP. All of these formulations include approximately 1 per cent 

carbon black to reduce the effects of UV degradation. 

Based on staff review of the information you provided, the appropriate-sized REBLOCK:IV may be used with wood or steel strong-post W-beam and Thrie-beam 

guardrail systems on the National Highway System (NHS) when such use is 

acceptable to the contracting agency. 

Please note the following provisions that apply to all FHWA letters of acceptance for 

synthetic offset blocks: 

• Any changes that could adversely influence the impact resistance of the REBLOCK:IV may require a new acceptance letter. 

• FHWA acceptance is based on the reported impact performance of the REBLOCK:IV and is not intended to address the durability of this product. 

• Should the FHWA discover that the qualification testing was flawed, that inservice performance reveals unacceptable safety problems, or that the device 

being marketed is significantly different from the version that was originally 

approved, it reserves the right to modify or revoke its acceptance. 

• You will be expected to certify to potential users that the material furnished 

has essentially the same chemistry, mechanical properties, and geometry as 

that submitted for acceptance, 

• When proprietary products, such as the RE-BLOCK:IV, are specified for 

use on Federal-aid projects, except exempt, non-NHS projects, they: (a) 
must be supplied through competitive bidding (b) the highway agency must 

certify that they are essential for synchronization with existing highway 

facilities or that no equally suitable alternative exists or; (c) they must be 

used for research or for a distinctive type of construction on relatively short 

sections of road for experimental purposes. Our regulations concerning 

proprietary products are contained in Title 23, Code of Federal Regulations, 

Section 635.411. 

Please contact Mr. Powers at (202) 366-1320 should you have questions. 

 Sincerely yours, 

(original signed by Carol H. Jacoby) 

 Carol H. Jacoby, P.E. 

 Director, Office of Safety Design 

Enclosure 
BACK SIDE

TOP

ALL DIMENSIONS SUBJECT TO

MANUFACTURERS TOLERANCES

COMPOSITION: 80% HDPE/20% CROSSLINK HDPE(PP)/~1% CARBON BLACK

AVERAGE BLEND +/- 2%

Comments:

PART# XP4

UNIT WEIGHT: 9

DATE MADE: 5/2/02

MODIFIED: 5/2/02

MADE BY: CGH

W-BEAM

DESCRIPTION:

BRYSON PRODUCTS, INC.

4" X 8" X 14" RE-BLOCK - ADJUSTABLE
BACK

BACK

TOP

TOP

ALL DIMENSIONS SUBJECT TO

MANUFACTURERS TOLERANCES

COMPOSITION: 80% HDPE/20% CROSSLINK HDPE(PP)/~1% CARBON BLACK

AVERAGE BLEND +/- 2%

Comments:

PART# XP4T

UNIT WEIGHT: 9

DATE MADE: 5/2/02

MODIFIED: 5/2/02

MADE BY: CGH

THRIE-BEAM

DESCRIPTION:

BRYSON PRODUCTS, INC.

4" X 8" X 21 5/8" RE-BLOCK - ADJUSTABLE