Texas Specification No.060-75-02
Effective Date:February 28, 1985
Last Revision:April 10, 1996 SPECIFICATION
TREAD RUBBER STOCK
(Pre-Cured) 1.SCOPE:This specification establishes the minimum
requirements for pre-cured tread rubber stock for use in
retreading pneumatic tires for light duty commercial and truck
2.APPLICABLE SPECIFICATIONS AND STANDARDS:References to
specifications, standards, test materials, and other documents
that are in effect on the date of the Invitation for Bids are
applicable.Copies of the referenced documents are available
from the issuing organizations at the addresses shown.The
following publications are part of this specification to the
extent specified herein:
2.1.FEDERAL TEST METHODS:General Services Administration
(GSA), Business Service Center, Region 3, Seventh and D Streets,
Southwest, Washington, DC 20407:
126.96.36.1991 -- Test Method for Rubber:Sampling and Testing.
188.8.131.5211 -- Test Method for Tensile Strength.
184.108.40.20621 -- Test Method for Elongation, Ultimate.
220.127.116.1131 -- Test Method for Tensile Stress.
18.104.22.16811 -- Test Method for Specific Gravity, Hydrostatic.
22.214.171.12401 -- Test Method for Chemical Analysis of Synthetic
Rubber Compounds, General.
126.96.36.19911 --Test Method for Identification of Synthetic
2.2.AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM), 1916
Race Street, Philadelphia, PA, 19103:
2.2.1.ASTM D 297 -- Chemical Analysis of Rubber Products.
2.2.2.ASTM D 412 -- Tension Testing of Vulcanized Rubber.
2.2.3.ASTM D 3182 -- Standard Materials, Equipment, and
Procedures of Mixing Rubber Compounds and for Preparing
Vulcanized Test Sheets.
3.REQUIREMENTS:The tread rubber stock furnished under this
specification shall meet or exceed the following requirements:
3.1.Type:The tread rubber shall be that known commercially as
the pre-cure type produced in lengths sufficient to tread at
least three (3) tires.
3.2.Grade:The trade rubber shall be a premium grade
compounded specifically for pre-cure retreading and to give top
performance and maximum mileage obtainable unless otherwise
specified (some trailer tires will require other standards).
The physical properties of the tread rubber shall be equal to or
better than those specified in Paragraph 3.5.
3.3.Materials:The tread rubber shall be free from excess
porosity, foreign material, and lumps of cured compound.
3.4.Standard Tread Rubber Formula:The standard tread rubber
formula to be used in compound trade rubber stock to furnished
to the State of Texas tire retreading plant shall be as follows:
188.8.131.52.Percentage of rubber hydrocarbon to be not less than
43% by weight.
184.108.40.206.Rubber hydrocarbon to contain approximately 50%
polybutadiene and approximately 50% styrenebutadiene.
220.127.116.11.Acetone extract to be 19% to 22%.
18.104.22.168.Carbon black of the ASTM N 234 or better type is the
only filler to be used.Percentage of black not to exceed 32%.
22.214.171.124.No off specification materials, reclaimed, or restored
materials are to be used.
3.5.Physical Properties:The physical properties (quality
control standards) of the tread rubber compound (finished
product) shall meet the requirements of the following Table 1,
when tested as specified in Table 2, Paragraph 4.
3.6.Material Preparation:the base of the cured tread strip
shall be buffed, cemented and covered with a backing material
for protection of the adhesive surface.
REQUIREMENTS OF PHYSICAL PROPERTIES
|Specific Gravity, g/cc||1.138 ± 0.01|
|300%, Modulus, psi:||1000 minimum|
|Tensile @ break, psi:||2000 minimum|
|Elongation @ break, percent||475 minimum|
|Shore A hardness||60 -- 70|
4.TESTING:Testing shall be done by or at the direction of,
the Commission and/or the receiving State agency.Tests shall
be performed on products from shipments to ordering agencies.
In the event products tested fail to meet or exceed all
conditions and requirements of this specification, the cost of
the samples used and the cost of testing shall be borne by the
TESTS FOR PHYSICAL PROPERTIES
|Characteristic||Test Method ASTM *1||Test Method Federal *2||Alternate Test Method *3|
|Preparation of Sample||ASTM D 3182|
|300% Modulus (Tensile Stress)||ASTM D 412||4131|
|Tensile Strength||ASTM D 412||4111|
|Elongation, percent||ASTM D 412||4121|
|Specific Gravity||ASTM D 297||14011||Zinc Chloride|
|Chemical Analysis||ASTM D 297||15001 and 15011|
NOTE *1 American Society for Testing and Materials.
NOTE *2 Federal Test Method Standard No. 601.
NOTE *3 Approved Alternate Test Method for Specific Gravity (Filtered
solutions of zinc chloride and distilled water).
5.INSPECTION:Inspection shall be done by or at the direction
of the Commission.The inspector shall have access to the plant
and premises of the manufacturer during all working hours
throughout the life of the contract.The manufacturer shall
furnish, at no charge and at the place of manufacture, all
equipment, apparatus, assistance, information, or evidence which
the inspector may require to satisfactorily determine that the
tread rubber being manufactured complies with all requirements
of this specification.
6.PACKAGING:Pre-cure tread rubber stock shall be packaged in
boxes.The type used shall be in accordance with the
manufacturer's standard practice, assuring safe delivery of the
material to its destination according to the specifications of
the ordering agency on the Invitation for Bids.
7.MARKING and/or LABELING:
7.1.Marking:Each shipping pallet shall be clearly marked with
the following data:
7.1.1. Name of contents.
7.1.2. Quantity contained.
7.1.3. Order number or contract number.
7.1.4. Name and address of ordering agency.
7.1.5. Agency requisition number.
7.1.6. Name and address of manufacturer.
7.2.Labeling:Each product container shall bear a securely
affixed and durable label showing the following:
7.2.1. Date of manufacture.
7.2.2. Trade size.
7.2.3. Trade design.
7.2.4. Weight of tread in container.
8.COMPLIANCE:In order for consideration to be given to the
bid on an item under this specification, the bidder must comply
with the following:
8.1.PRODUCT IDENTIFICATION:The make, model number, name of
the manufacturer, brand or trade name, etc., as applicable, of
the item which the vendor proposes to furnish must be stated as
part of the bid.
8.2.EXCEPTIONS:Notwithstanding the above, any exception taken
by the bidder to the requirements and conditions of this
specification must be stated and described in detail as a part
of the bid.If no exceptions or deviations are identified in
this manner, the items must be furnished exactly as described
8.3.PROOF:The bidder shall bear the burden of proof of
compliance with this specification.
9.ORDERING DATA:When ordering products conforming to this
specification the requisitioning agency shall specify the
9.1.The number of this specification (060-75-02).
9.2.The total number of pounds required.
9.3.Shipping instructions, to include acceptable means of
10.AWARD OF BID:The award of bid will be based on the price
of tread rubber per pound (F.O.B. destination).
11.AVAILABILITY OF SPECIFICATIONS:Copies of this
specification may be obtained by calling or writing:
Texas Procurement and Support Services