retroreflective road markings - euroadbead color of the road marking is retroreflected. the striping...
TRANSCRIPT
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
Retroreflective Road Markings
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
Road markings: safer mobility by day and night
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
The „secret“ of night time visibility of road markings: glass beads
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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.
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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.
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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.)
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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)
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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
– Typical application rates of 400 – 600 g/m2
• BLENDS
– Blend size ranges from 100-1300 microns
– Applied in any road marking material for improved performance
– Typical application rates of 400 – 600 g/m2
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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 -
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
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
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
5x brighter with high performance glass beads
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
M. SWAROVSKI GmbH / Amstetten / Lower Austria
SWARCO‘s Competence Center for Glass Technology
linked to Reflective Road Safety
SWARCO MS/RN / Wattens Saudi Arabia 5 Dec 2007
Reflective Road Markings presentation
Thanks for your attention !