La. Admin. Code tit. 73 § III-305

Current through Register Vol. 50, No. 11, November 20, 2024

Section III-305 - Minimum Standard for Thermoplastic Pavement Markings

A. Description. This specification covers hot-sprayed or hot-extruded reflective thermoplastic compound for pavement markings on asphaltic or portland cement concrete pavement. Thermoplastic marking material applied to asphaltic surfaces shall consist of an alkyd-based formulation. Thermoplastic marking material applied to portland cement concrete surfaces shall consist of either an alkydbased or hydrocarbonbased formulation. Material shall be so manufactured as to be applied by spray or extrusion to pavement in molten form, with internal and surface application of glass spheres, and upon cooling to normal pavement temperature, shall produce an adherent, reflectorized pavement marking of specified thickness and width, capable of resisting deformation.

1. Material shall not scorch, break down, or deteriorate when held at the plastic temperature specified in Subsection 732. 03(d)(1)* for four hours or when reheated four times to the plastic temperature. Temperature-vs-viscosity characteristics of plastic material shall remain constant when reheated four times, and shall be the same from batch to batch. There shall be no obvious change in color of material as the result of reheating four times, or from batch to batch.

B. Suitability for Application. Thermoplastic material shall be a product especially compounded for pavement markings. Markings shall maintain their original dimension and placement and shall not smear or spread under normal traffic at temperatures of below 140 ° F (60 ° C) . Markings shall have a uniform cross section. Pigment shall be evenly dispersed throughout its thickness. The exposed surface shall be free from tack and shall not be slippery when wet. Material shall not lift from pavement in freezing weather. Cold ductility of material shall be such as to permit normal movement with the pavement surfaced without chipping or cracking.

C. Standard Thermoplastic Pavement Markings. Materials shall be approved products listed in Q PL 63 and shall comply with AASHTO M 249 and the specifications as stated herein with the following modifications.

1. Color. The yellow thermoplastic shall comply with the requirements of Table 1015-7 when tested in accordance with ASTM E 1349.

Table 1015-7 Color Specification Limits (Daytime)
Color	1		2		3		4
Color	x	y	x	y	x	y	x	y
Yellow	0.4756	0.4517	0.4985	0.4779	0.5222	0.4542	0.4919	0.4354
(The four pairs of chromaticity coordinates determine the acceptable color in terms of the CIE 1931 Standard Colorimetric System measured with Standard Illuminant C.)

2. Whiteness Index. The white thermoplastic shall have a minimum whiteness index of 40 when tested according to ASTM E 313.

D. Inverted Profile Thermoplastic Pavement Markings. Materials shall be approved products listed in Q PL 63 and shall comply with AASHTO M 249 and these specifications as follows:

1. Bead Content. Glass bead content for inverted profile thermoplastic pavement markings shall be in accordance with Table 1015-8.

Table 1015-8 Bead Content
U.S. Standard Sieve Size (Microns)	Class A¹-10% min. (by wt.) of thermoplastic compound, Percent Retained	Class B¹-25% min. (by wt.) of thermoplastic compound
14 (1400)	0-1	Beads shall meet gradation requirement of AASHTO M 247, Type I.
16 (1190)	0-20
18 (1000)	0-45
20 (840)	30-80
30 (595)	20-50
Pan	0-10

¹Refer to Section 732 when applying as drop-on beads for inverted profile thermoplastic pavement markings.

2. Bead Quality. The glass beads shall be coated with A-116 Silane or other adhesion promoting coating. The glass beads shall have a maximum of 3 percent irregular particles and a maximum of 5 percent air inclusions. The percentage of true spheres shall be 90 percent minimum for Class A beads and 80 percent minimum for Class B beads.

3. Binder Content. The binder content of the thermoplastic material shall be 19 percent minimum.

4. Titanium Dioxide. The titanium dioxide shall meet ASTM D476, Type II, Rutile grade, 93 percent minimum titanium content.

5. Yellow Pigment. The yellow pigment for the yellow thermoplastic material shall be 4 percent minimum.

6. Color. The yellow thermoplastic shall comply with the requirements of Table 1015-9 when tested in accordance with ASTM E 1349.

Table 1015-9 Color Specification Limits (Daytime)
Color	1		2		3		4
Color	x	y	x	y	x	y	x	y
Yellow	0.4756	0.4517	0.4985	0.4779	0.5222	0.4542	0.4919	0.4354
(The four pairs of chromaticity coordinates determine the acceptable color in terms of the CIE 1931 Standard Colorimetric System measured with Standard Illuminant C.)

7. Whiteness Index. The white thermoplastic shall have a minimum whiteness index of 40 when tested according to ASTM E 313.

8. Specific Gravity. The specific gravity of the thermoplastic pavement marking material shall not exceed 2.35.

9. Flowability. After heating the thermoplastic material for four hours +- 5 minutes at 425+- 3 ° F (218+- 2 ° C) and testing flowability, the white thermoplastic shall have a maximum percent residue of 22 percent and the yellow thermoplastic shall have a maximum residue of 24 percent.

10. Reflectivity. The initial reflectance for the in-place marking shall have the minimum reflectance value of 450 mcd/lux/sq m for white and 350 mcd/lux/sq m for yellow when measured with a geometry of 1.5 degrees observation angle and 86.5 degrees entrance angle.

11. Wet Reflectivity. The minimum in-place marking when wet shall have the minimum reflectance value of 200 mcd/lux/sq m for white and 175 mcd/lux/sq m for yellow when measured with a geometry of 1.5 degrees observation angle and 86.5 degrees entrance angle. The stripe shall be wet utilizing a pump-type garden sprayer for 30 seconds. After five seconds, place the reflectometer on the stripe and measure the retro reflectance.

12. Retained Reflectivity. The thermoplastic pavement marking material shall retain the minimum reflectance value of 130 mcd/lux/sqm for at least four years after placement. Failure to meet this requirement shall require the contractor to replace the portion of the material shown to be below these minimums. The contractor shall provide a written warranty indicating the terms of this requirement.

13. Inverted Profile. The thermoplastic pavement marking material shall be applied to have individual profiles having a minimum height of 0.140 inches (3.5 mm) with the recessed inverted profiles having a thickness of 0.025 to 0.050 inches (0.6 mm to 1.25 mm). The profiles shall be well defined and not excessively run back together.

La. Admin. Code tit. 73, § III-305

Promulgated by the Department of Transportation and Development, Office of Weights, Measures and Standards, LR 24:707 (April 1998), amended LR 30:506 (March 2004).

In §305. A 1, Subsection 732. 03(d)(1) is found in Louisiana Standard Specifications for Roads and Bridges.*

AUTHORITY NOTE: Promulgated in accordance with R.S. 48:35.