Maximising Durability and Performance of Marking Systems. NZRF Conference Rotorua Aug

Transcription

1 Maximising Durability and Performance of Marking Systems NZRF Conference Rotorua Aug

2 Factors affecting performance AS Pavement Texture Applications Conditions Application Equipment Application Rate Aggregates Glass Bead Protection from Traffic Traffic Type and Volume Road Geometry and Dimensions Initial and Subsequent Application Compatibility Effect of Contaminants or pre treatments Pavement Luminance

3 Any System have 3 Critical components Effective binder Waterbased, PMMA Thermo Quality reflective Media Potters Glass beads 3M Elements Application technique

4 Components affecting systems performance Critical Components in Systems Binder content - too low / too high Binder quality- poor Reflective media quantity- too low Reflective media quality Application Common problems Excessive wear / dirt pickup, extra cost Yellowing, unpredictable reactions, slow dry, poor adhesion to substrate or reflective media Low retro s, poor retention, excessive wear Poor retention, Low optical quality, eg rounds or inclusions, crushing, dustiness Poor bead retention, rapid wear, low retro, excessive downtime, blockages, incorrect film weights, uncontrolled variances, equipment wear, product loss, high consumables, risky behaviour

5 Application related problems by Binder type Thermoplastic Low initial retro Rapid loss of retro in service Diagnosis Poor quality or insufficient glass bead, excessive temperature at application, incorrect coating on bead, road needs trafficking Thermo too cold at application, incorrect coating on bead Paint or PMMA Low initial retro Rapid loss of retro in service Diagnosis Early bead loss, insufficient film thickness, insufficient beads, incorrect bead coating, bead roll, early trafficking Insufficient paint, insufficient bead

6 Common Diagnosis Effect of Traffic Adhesion Coatings Paint film thickness Bead embedment Bead placement and population

7 Effect of Traffic Optimum Retro Don t measure too soon after application. Paint dust, Thermo waxes Coatings Angular particles shadowing Requires some trafficking and weathering Measure approx one week after Some markings continue to rise over 1yr

8 Adhesion Coatings Proprietary chemical coating Promotes adhesion Binder specifics Other coatings: water proofing or flow enhancers R- Recommended NR-Not Recommended O- Optional System Type B Type C Type D or DHR Thermo NR NR R PMMA R R R Waterborne Paint NR NR O

9 Adhesion Coatings for PMMA No Coating Nearly 100% bead loss Adhesion Coated 100% bead retention

10 Adhesion Coatings for Thermo R etro reflectivty M X30 m cd /lu x/m NOTE: The initial measures w ere taken too soon after application. They should have been exposed to traffic for a couple of days to remove the w axes etc, prior to measuring. The 'initial' may then have AU011 at 51 months (April 2005) - Thermoplastic. Accelerated wear testing by line placement. Intervention Level 150mcd/lux/m2 Adhesive coated Visibeads Uncoated Visibeads Initial 3 month 7 month 10 months 13 mths 18 mths 22 mths 26 mths 32 mths 38 mths 45 mths 51 mths Period of Trafficking. With Vehicles 2.5 million"screwing' around these lines to date, with 0.75 million being trucks (29% ).

11 Paint Film Thickness

12 The surface elements provide a barrier between the binder and the vehicle s tyres to enhance durability

13 Bead Embedment

14 Glass beads require 60% embedment for optimum retroreflectivity and to provide a mechanical lock for durability

15 Bead Placement and Population No bead roll Retroreflectivity equalised for both viewing directions No bead bounce Double the retroreflectivity

16 Do it right in waterborne Section 26 at 53 months 14mm chipseal Waterborne Paint / Visimax Type D-HR Performer Dry retro 232mcd Wet retro 85mcd BPN 55 After approx 23 million LANE vehicles Ref AU017 Trial

17 Do it right in PMMA Section 33 at 53 months Best PMMA Performer Dry retro 292mcd - Wet retro 122mcd - BPN 51

18 Do it Right in thermo 2 ½ years Est ADT 50,000. Dense grade asphalt pavement. Edgeline observations: Almost 100% loss of the smaller sized beads. Dry retro 440mcd, wet retro 107mcd.

19 Summary Choosing good quality products is only half the picture The other half is specification and application SPECIFICATION and APPLICATION The grade of good quality glass bead- Pristine Type B vs Type D drop on The retained bead rate or bead retention vs bead application rate A clear expected retro number 12 months into the life cycle Paint film thickness matching the type of substrate and bead type Wet and dry specs for thermoplastics Coating recommendations for PMMA in Audio Tactile markings AND then know what to look for