A.
General:
Pavement markings shall conform, except as noted, to the requirements of Item 670, “Pavement Markings (Reflectorized Paint)” of the Standard Specifications for Construction of Highways, Streets and Bridges of the Texas Department of Transportation.
B.
Materials:
Article 670.1 Materials is supplemented as follows:
1.
Traffic stripe reflective glass spheres.
a.
Imperfect glass sphere test: The glass spheres shall not contain more than thirty (30) percent (by weight) irregular shaped particles when tested by ASTM D-1155-53. Spheres shall be essentially free of sharp angular particles, and particles showing milkiness or surface scarring or scratches. Spheres shall be water white in color.
b.
Gradation Test: The glass spheres shall meet the following gradation requirements when tested:
Opening - U.S. Std. Sieves | Percent Passing |
|---|---|
#20 | 100 |
#30 | 80 - 100 |
#50 | 18 - 35 |
#100 | 0 – 4 |
c.
Index of Refraction Test: The spheres, when tested by the liquid immersion method at 25° C shall show an index of refraction within the range of 1.50 to 1.98.
d.
Material Requirements: The spheres shall be capable of being readily wet with water when tested according to test Method Tex-82B. The spheres shall show no tendency toward decomposition, surface etching, change in retro-reflective characteristics, or change in color after 24 hours exposure (according to test method Tex-833B) to weak alkali, or 100 hours of weather-o-meter exposure.
e.
General Requirements: Moisture content, spheres shall contain less than 1/4 of 1% moisture by weight; spheres shall be manufactured from glass, shall be free of trash, dirt, etc. and shall show no evidence of objectionable static electricity when flowing through a regular traffic bead dispenser.
f.
Recommended Application Rate: Six (6) pounds per gallon paint.
2.
Traffic Marking Paint.
a.
Scope and Classification.
(1)
Scope.
It is the intent of these specifications to describe minimum requirements for white and yellow traffic marking paint to be used for marking concrete and asphaltic street surfaces.
(2)
Classification.
The paint shall be suitable for application by means of spray-type pavement marking equipment used by the Contractor and when applied by such equipment shall be capable of producing a solid, full width line of required thickness.
b.
Applicable Specifications.
(1)
The paint shall be capable of being broken up and mixed without difficulty by use of a paddle or paint shaker and show the desired characteristics at any time within a period of six (6) months from day of delivery. If it becomes necessary during the six (6) month period, the paint shall be tested in accordance with ASTM designation D-869 and paint rated below four (4) shall be considered unsatisfactory.
(2)
All materials required to meet Federal or ASTM specifications must meet the specification as shown.
ASTM Spec. D-476-73, Type II |
Federal Spec. TT-P-463A, Type I |
National Bureau of Standards - Chromatic Standard |
No. Sch-30 |
Federal Spec. TT-P-403A |
Federal Spec. MIL-C-429C, Type I |
ASTM Spec. D-362-75 |
ASTM Spec. D-740-69 |
ASTM 600-73 |
Tex-806-B |
Tex-811-B |
c.
Functional Requirements.
(1)
The paint shall be homogeneous, shall be well ground to a uniform and smooth consistency, and shall not skin or settle badly, nor cake, sliver, thicken, curdle, or gel in the container.
(2)
The paint, when applied to a bituminous pavement surface under normal field conditions at the required rate of 0.15 inches wet film thickness, shall have a maximum “no pickup” drying time of fifteen (15) minutes to prevent displacement or discoloration under traffic.
(3)
In preparation of the paint, the pigments shall be dispersed in the vehicle by appropriate methods so that the fineness reading of not less than four (4) is obtained with a Hegman grind gauge.
(4)
Consistency viscosity as determined by the Stromer Viscosimeter at 25° C shall be from 85 to 100 KU.
(5)
A thin film of paint spread on a glass plate and allowed to dry thoroughly shall not darken or show and discoloration when subjected to ultra-violet rays for a period of five minutes.
d.
Material Requirements.
(1)
Raw Materials:
(a)
Substitutions - The exact brand and types of raw materials used in the wet standards are listed for the purpose of facilitating the selection of parallel materials equal, not only in quality and composition, but also in physical and chemical behavior after aging in the finished product.
(b)
It shall be the responsibility of the contractor to utilize materials that not only meet the individual raw material specification, but also that produce a coating that meets the specific formula requirements.
(c)
Materials required to meet Federal and ASTM specifications must meet the specification as shown.
(2)
Pigments.
b.
Medium Chrome Yellow - Color.
Characteristics and Color. The luminance factors of the pigment shall be within the limits listed below when tested before and after exposure. |
Min. | Max. | |
|---|---|---|
Initial | 53 | 59.0 |
Final | 45 |
In addition, the allowable change between the initial and final luminance factors shall be no more than 9 units. |
The initial x, y chromaticity color coordinates of the pigments shall be within the rectangle defined by the sets of coordinates shown below. |
X | Y |
|---|---|
0.490 | 0.455 |
0.511 | 0.433 |
0.514 | 0.480 |
0.535 | 0.458 |
Method of Test: The pigments shall be tested according to test method Tex-810-B. |
Color Standard: National Bureau of Standards Chromatic Standard No. Sch-30. |
The formation of the test enamel using the pigments to be tested is as follows: |
Materials | Part by Weight |
|---|---|
Medium Chrome Yellow | 54.0 |
Long Oil Alkyd Resin (1) | 31.5 |
4% Calcium Drier | 0.6 |
6% Colbalt Drier | 0.3 |
Anti-Livering Agent | 0.1 |
Anti-Skinning Agent | 0.2 |
Mineral Spirits (2) | 13.3(3) |
(1)
Alkyd Resin Solution meeting Federal specification TT-R226-D, Type I, Class A, November 17, 1971.
(2)
Mineral Spirits meeting Federal specification TT-T-291E, October 12, 1970, amend-1 6/12/75.
(3)
The amount of mineral spirits may be varied slightly to produce the desired grinding consistency. Number of coats: Two (2).
(3)
Inert.
(a)
Talc, paint-grade magnesium silicate: Shall meet Federal Specification TT-P-403A.
(b)
Calcium Carbonate:
CaCO 3 | Minimum 97.0% |
H2O | Maximum 0.4% |
Specific Gravity | 2.63 - 2.73 |
Weight retained on #325 Screen | Maximum 0.75%. |
Color: Equal to material listed in standard formula. Substitution in standard formula shall not result in viscosity variation greater than 4 K.U. |
(4)
Resins:
(a)
Chlorinated Paraffin: Shall meet Federal Specification MIL-C-429C, Type I, May 6, 1969.
(b)
Chlorinated Rubber: Viscosity @ 25°C *20% solution with Toluene* 406 cups.
*Toluene shall meet ASTM Specification D-362-75.
(c)
Traffic paint alkyd resin solution:
(1)
General:
Type: Pure, drying alkyd |
Length: Medium |
Type Oil: Soya, linseed or tall. No mixture of two or more oils will be permitted. |
Type Solvent: Toloul |
Compatibility: A solution of one part 75% traffic alkyd and five parts toloul shall be clear. |
A solution containing the equivalent of 150 grams of 5 cps chlorinate rubber, 130 grams of 75% traffic alkyd, 200 grams of methyl ethyl ketone shall be clear, transparent, and show no separation after 24 hours of storage in a 3/4 full test tube at 80 degrees, plus or minus 5 degrees F. This rubber-alkyd-solvent solution shall produce a clear film upon drying. |
(2)
Solid Resin Basis:
Percent Phthalic Andydrides | 33 to 37 |
Percent Oil Acids | 48 to 55 |
Acid number, maximum | 8.0 |
Ash residue, maximum | 0.10% |
Unsaponifiable, maximum | 2.0% |
Iodine number of fatty acids, minimum | 115 |
Retractive Index of fatty acids, minimum | 1.4660 |
Percent Rosin based on fatty acids (tall oil alkyds), maximum | 1.0 |
(3)
45% Solids Basis:
Color: Gardner 1953 Standard - 9 maximum
Drying Time: A wet film 3 mils thick shall set to touch in not more than 90 minutes.
[Driers: Based on the resin solids present, add the equivalent of 0.06% Cobalt (metal) and 1.0% lead (metal).]
(4)
Turbidity: In addition to the above requirements, the traffic alkyd resin shall meet the following % transmittance requirements when tested according to test methods Tex-814-B, utilizing methyl alcohol as primary solvent, and methyl alcohol as precipitating agent.
% Transmittance | Minimum | Maximum |
|---|---|---|
T1 | 10% | |
T2 | 70% |
Calcium volume in milliters of precipitating agent as follows: V1 - 91X. |
Where V1 = volume of precipitating agent required for T1 |
X = grams of alkyd resin solids and V2 = 1.398 V1 |
Where V2 = additional volume of precipitating agent required for T2. |
(7)
Formula:
a)
White Traffic Paint:
Pounds | |
|---|---|
Traffic Alkyd, 75% Solids | 130 |
Chlorinated Rubber, 5 cps. Hercules, Parlon S-5 | 150 |
Chlorinated Paraffin, Type I, Hercules, Chlorafin 40 | 75 |
Treated Bentonite Clay | 5 |
Titanium Dioxide, Rutile, DuPont, R-900 | 200 |
Lead Free Zinc Oxide, ASARCO, AZO-33 | 50 |
Talc, Nytal 300 | 225 |
Calcium Carbonate, T.W., Snowflake White | 250 |
24% Lead Drier | 3 |
6% Colbalt Drier | 2 |
Thermolite 813, M & T Chemical Inc. | 0.75 |
Aromatic Naphtha, SC-150 | 5 |
Methyl Ethyl Ketone | 245 |
1,340.75 |
Grind 4 minimum particles: 8 maximum (Test method Tex 806-B) |
Gallon Weight + 0.05 of theoretical gallon weight |
Consistency: 85 to 100 K.U. |
Skinning: No skinning within 48 hours (Test Method Tex 811-B) |
b)
Yellow Traffic Paint:
Pounds | |
|---|---|
Traffic Alkyd, 75% Solids | 130 |
Chlorinated Rubber 5 cps., I.C.I. Allporene X-5 | 150 |
Chlorinated Paraffin, Type I, I.C.I. Cereclor 42 | 75 |
Treated Bentonite Clay | 5 |
Titanium Dioxide, Rutilel, DuPont, R-900 | 25 |
Lead Free Zinc Oxide, ASARCO, AZO-33 | 50 |
Medium Chrome Yellow, DuPont, Y-469-D | 175 |
Calcium Carbonate, T.W., Snowflake White | 250 |
Talc, Nytal 300 | 250 |
24% Lead Drier | 3 |
6% Cobalt Drier | 2 |
Thermolite 813, M & T Chemical Inc. | 0.75 |
Aromatic Naphtha, SC-150 | 5 |
Methyl Ethyl Ketone | 255 |
1,370.75 |
Grind 4 minimum particles: 8 maximum (Test Method Tex 806-B) |
Gallon Weight 0.05 of theoretical gallon weight |
Consistency: 85 to 100 K.U. |
Skinning: No skinning within 48 hours (Test Method Tex 811-B) |
(Ordinance 2007-106, App. B, adopted 3/20/07)