400 Seventh St., S.W. 

Washington, DC 20590 March 8, 2007 

In Reply Refer To: 

HSSD/B-155 

Mr. Ing. M.E. Hernando Salas J. 

Corpacero 

Gerente Division Armco 

Carrera 68 # 23 – 52 

Bogota, Colombia 

Dear Mr. Salas: 

In your November 15, 2006, letter to Mr. Nicholas Artimovich of my staff, you sent him a copy 

of a test report prepared by the Texas Transportation Institute, dated November 10, 2006, and 

entitled “Pendulum Testing of the Corpacero Spacer Block” and a CD showing the tests that 

were conducted with your product. You requested acceptance of your product for use with 

strong steel-post W-beam guardrail on the National Highway System (NHS). 

The Corpacero HDPE spacer blocks were 350 mm (13.8 inches) tall, 187 mm (7.4 inches) deep, 

and 100 mm (3.9 inches) wide. The chemical composition of the spacer blocks was 55.0 percent 

recycled HDPE, 43.5 percent recycled rubber, 1.0 percent Black Master Batch, and 0.5 percent 

anti-oxidizing agent, produced by Mater Andina S.A. ref. M010051093. The spacer block used 

in the first pendulum test weighed 3.7kg (8.2 pounds) and the block used in the second pendulum 

test weighed 3.5 kg (7.8 pounds). The Corpacero HDPE spacer blocks were mounted on 

W6 x 9 steel posts, which were mounted on a steel reaction plate. A W-beam backup plate was 

mounted on the front of the spacer block to simulate a W-beam guardrail. A drawing of the 

Corpacero HDPE spacer block is enclosed for reference. 

In both tests the posts rotated approximately130 degrees and the W-beam backup plate separated 

from the spacer block. The blocks themselves remained on the post in one piece with only a 

slight tear on the right side lip and the face was indented. 

Based on the results of the pendulum tests using the Corpacero offset block, your product may be 

considered acceptable for use when requested by a highway agency on the NHS with a strongpost W-beam guardrail when it conforms to the dimensions noted above and the enclosed 

drawings, is composed of the same materials as the tested blocks, and is installed flush with the 

top of the post. As with all other alternative material offset blocks accepted for use on the NHS, 

this acceptance is based solely on the reported impact performance of the Corpacero block and is 

not intended to address the long-term performance or durability of the product. Field 

installations should be carefully monitored to verify expected performance and service life. 
2

Please note the following standard provisions that apply to the FHWA letters of acceptance: 

• Our acceptance is limited to the crashworthiness characteristics of the devices. 

• Any changes that may adversely influence the crashworthiness of the device will require 

a new acceptance letter. 

• Should the FHWA discover that the qualification testing was flawed, that in-service 

performance reveals unacceptable safety problems, or that the device being marketed is 

significantly different from the version that was crash tested, it reserves the right to 

modify or revoke its acceptance. 

• You will be expected to supply potential users with sufficient information on design and 

installation requirements to ensure proper performance. 

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

essentially the same chemistry, mechanical properties, and geometry as that submitted for 

acceptance, and that they will meet the crashworthiness requirements of the FHWA and 

the NCHRP Report 350. 

• To prevent misunderstanding by others, this letter of acceptance, designated as number 

B-155, shall not be reproduced except in full. As this letter and the supporting 

documentation which support it become public information, it will be available for 

inspection at our office by interested parties. 

• If the Corpacero HDPE spacer block is or becomes patented, it is considered 

"proprietary”. When proprietary devices are specified by a highway agency for use on 

Federal-aid projects: (a) they must be supplied through competitive bidding with equally 

suitable unpatented items; (b) the highway agency must certify that they are essential for 

synchronization with existing highway facilities or that no equally suitable alternative 

exists; (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, a copy of which is enclosed. 

• This acceptance letter shall not be construed as authorization or consent by the FHWA to 

use, manufacture, or sell any patented device for which the applicant is not the patent 

holder. The acceptance letter is limited to the crashworthiness characteristics of the 

candidate device, and the FHWA is neither prepared nor required to become involved in 

issues concerning patent law. Patent issues, if any, are to be resolved by the applicant. 

Sincerely yours, 

John R. Baxter, P.E. 

Director, Office of Safety Design 

Office of Safety 

Enclosures