retroreflective road markings - euroadbead color of the road marking is retroreflected. the striping...

SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007

Reflective Road Markings presentation

Retroreflective Road Markings



Road markings: safer mobility by day and night



The „secret“ of night time visibility of road markings: glass beads



What happens at night

Without beads, there is no retroreflection !

The poor visibility of the road marking is only based

on the contrast between the illuminated striping and

the dark pavement.



What happens at night

Glass beads create retroreflection!

The visibility of the road marking rises significantly,

because the color of the striping is reflected to the

car driver.



Retroreflection – how it works

The headlight beam penetrates the glass bead, hits the

pigmented road marking, and is reflected.

The color of the road marking is retroreflected.

The striping seems to „light up“.

reflected light

marking material



Quality features of glass beads

• refractive index

low index: 1.5

high index: >1.9

• roundness (min. 80%)

• transparency

• sieving gradations

• coatings

flat glass cullet is recycled into a road safety product



Quality of retroreflection depends on

• Bead quantity applied

• Bead distribution in/on the marking

• Ratio of bead size and layer thickness

of the marking

• Degree of bead embedment

(ideally 50 – 60 % of bead circumference)

• Viscosity of marking material

• Ambient conditions

(rain, quality of road surface, etc.)



Glass bead types

• Drop-on beads

– For high initial retroreflection, applied onto the road marking material before it „sets“ at a consumption rate of 400-600 g/m2

• Intermix beads

– Mixed into the road marking material for improved long term reflectivity and durability of the line (thermoplastics)

• Injection beads

– Beads that are injected into the road marking material during the application process (high build paint)



Drop-on bead types

• STANDARD

– Size range from 100 - 800 microns

– Primarily in paints, thermoplastics, and cold plastics

– Typical application rates of 400 – 600 g/m2

• LARGE (MEGALUX-BEADS®)

– Size ranges from 600-1500 microns

– Higher roundness (>90%) and smoother surface

– High performance road marking systems (wet night – profiled), cold plastics and thermoplastics


• BLENDS

– Blend size ranges from 100-1300 microns

– Applied in any road marking material for improved performance




Glass bead specification applied in Saudi Arabia

AASHTO M247: Glass Beads used in Traffic Paints

• The beads shall be transparent, clean, colorless glass, smooth and

spherically shaped, free from milkiness, pits, or excessive air

bubbles and conform to:

• Roundness minimum 70%

• Refractive index minimum 1.5

• Crushing resistance: retained 0.425 mm (no. 40) sieve 133 N

(30 lb) minimum

• Moisture Resistance-Flow Characteristics: beads shall not

absorb moisture in storage; shall remain free of clusters and lumps

and shall flow freely from dispensing equipment

• Flotation: minimum 90% beads shall float in xylene



Thermoplastic specification applied in Saudi Arabia

AASHTO M249: White and yellow reflective

thermoplastic striping material (solid form)

• colors: white or yellow

• resins: alkyd or hydrocarbon

• specific gravity of thermoplastic material shall not exceed 2.15

• material supplied either in granular or block form

• application by spraying, screed extrusion, or ribbon extrusion, as

specified by the purchaser



Thermoplastic specification applied in Saudi Arabia

The thermoplastic material shall be homogeneously composed

of pigment, filler, resins and glass reflectorizing spheres.

Composition acc. to AASHTO M249 [%]:

COMPONENT WHITE YELLOW

Binder 18.0 min 18.0 min

Glass beads 30-40 30-40

Titanium dioxide 10.0 min -

Calcium carbonate & inert fillers 42.0 max at the option of the manufacturer

Yellow pigments -



Reflectivity standards (European Standard EN 1436)

EN 1436 defines the performance requirements of road

markings:

• daytime visibility

• nighttime visibility

• color

• skid resistance

Minimum nighttime visibility value

for white road markings in Germany:

> 150 mcd



5x brighter with high performance glass beads



M. SWAROVSKI GmbH / Amstetten / Lower Austria

SWARCO‘s Competence Center for Glass Technology

linked to Reflective Road Safety



Thanks for your attention !

retroreflective road markings - euroadbead color of the road marking is retroreflected. the striping...

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