Non-mechanical markers Road surface marking

1 non-mechanical markers

1.1 paint
1.2 stones
1.3 thermoplastic

1.3.1 preformed thermoplastic


1.4 preformed polymer tape
1.5 epoxy
1.6 negative impacts road surface
1.7 glass beads

non-mechanical markers
paint

paint, additives such retroreflective glass beads, used mark travel lanes. used mark spaces in parking lots or special purpose spaces disabled parking, loading zones, or time-restricted parking areas. colors these applications vary locality. paint low-cost marking , has been in widespread use since approximately 1950s.

paint consists of 3 main components: pigments, resins or binders, , water or solvents. pigments finely grounded materials give out colors or block out surface beneath it. may contain other materials such uv stabilizer, , fillers bring out color pigments required level. resins or binders glue of paint bind pigment , glass beads road surface. resins water-based paints polyvinyl acetate latex, methyl methacrylate or acrylic resin. resins solvent-based paints linseed or soya oils , alkyd resins. pigments , resins mixed water water-based paints , solvents solvent-based paints can applied onto road surface. solvents use can naphtha, toluene, methanol, methylene chloride, , acetone. due environmental concerns, jurisdictions has restriction on solvent-based paints.

pigment yellow 10 common yellow colorant used road marking on u.s. highways.

paint applied right after road has been paved. road marked commonly truck called striper. these trucks contain hundreds of gallons of paint stored in huge drums sit on bed. markings controlled manually or automatically controller sits on bed. paint run through series of hoses under air pressure , applied roadway surface along application of glass beads retroreflectivity. after application, paint dries quickly. glass beads mixed in paint , applied together, not recommended method. usual method use separate gun spray glass beads on wet paint during application.

painted symbols, such turn-lane arrows or hov lane markers, applied manually using stencils. painted markings last 9 36 months. there water-based paints can applied @ double level of thickness of typical latex paints. technique can extend life of markings.

stones

stone road marking in pedestrian crossing in padua, italy

in roads paved setts (like belgian blocks or sampietrini) or cobblestones, markings can made white blocks or stones, marble or other light-colored rocks. kind of marking long lasting, slippery in rain or wet conditions unless surfaced matte or rough finish.

thermoplastic

one of common types of road marking based on balance between cost , performance longevity, thermoplastic binder systems based on 1 of 3 core chemistries: hydrocarbons, rosin esters or maleic modified rosin esters (mmre). thermoplastic coatings homogeneous dry mixes of binder resins, plasticizers, glass beads (or other optics), pigments, , fillers. use has increased on paints due performance benefits of increased durability, retro-reflectivity, , lack of voc solvents.

thermoplastic markings applied using specially designed vehicles. thermoplastic marking mode should apply equipment called road marking machine coat traffic lines, , road paint needs preheating device commonly called preheater. thermoplastic mix heated in trucks 200 °c (400 °f) before being fed application apparatus. screed box or ribbon gun. after thermoplastic has been applied, glass beads laid onto hot material embed before plastic hardens. these beads provide initial retroreflection. marking wears during use , initial beads lost, beads mixed binder uncovered, providing long term retroreflectivity. these can made exceptionally thick produce rumble strip effect.

the thermoplastic marking coating sets quickly. melt adhesion of synthetic resin makes hot-melt paint adhere road surface. additives in coating paint increases coating plasticity, improving anti-settling, anti-pollution, anti-tarnish. thermoplastic marking paint commonly produced in yellow , white. white marking paint contains titanium white, zinc oxide, lithopone, while yellow paint heat-yellowing lead.

in warm climate areas, thermoplastic markings can last 3 6 years. however, snowplows can damage thermoplastics limit usage in cold climate areas. filling materials of road paint can affect mechanical strength, abrasion resistance , hue of coating film. particle size of paint powder influences flow, sedimentation, , surface processing.

preformed thermoplastic

preformed thermoplastic markings ready applied road surface blow torch in brussels, belgium

preformed thermoplastic pavement markings (sometime called tape , not confused preformed polymer tape) thermoplastic cut final shapes manufacturers , ready position onto asphalt or concrete pavement surface. preformed thermoplastics put place on road surface , applied using propane heat torch. models require heating road surface prior placement of preformed thermoplastics. these markings used because of durability , cost-effective service life. since plastics melted surface, not damaged snowplows. typically, preformed thermoplastic markings can last 3 6 years. common applications of preformed thermoplastic pavement markings found @ intersections transverse markings such stop lines, legends, crosswalks, arrows, bike lane symbols, , accessibility symbols.

preformed polymer tape

preformed polymer tapes used crosswalk markings in street of new york city. notice tape failure on left stripe.

commonly referred tape or cold plastic, product heavy-grade material reflective beads embedded in plastic. commonly used mark crosswalks, stop bars, , traffic guidance such turn lanes, hov lanes, train crossings, pedestrian crossings, taxi lanes, bus lanes, , bike lanes. there 2 ways apply tape:

overlay—the application being laid on surface of pavement. using industrial-grade rubber cement, once tape combined pavement, should last 3 years. major obstacles estimated life snow-plows, salt, , mis-application.
inlay—the tape physically becomes part of asphalt. using heat generated in paving process, road workers lay special tape on asphalt in hardening process, , rollers compress 2 together.

the life of preformed polymer tapes can vary based on applications. if applied correctly, can last between 4 , 8 years. however, there have been cases tape failures start after installation. conditions may contribute tapes peel off time of year of installation close winter, surface preparation, , workmanship. technique can used minimize tape getting scraped off snowplows sandblasting groove surface , fixing tape onto groove. technique diminishes advantage of low labor cost of tapes. preformed polymer tape markings slippery when wet, in large sections such crosswalks, , caution should used due poor wet traction.

epoxy

epoxy contains 2 parts pigmented resin base , catalyst. 2 parts mixed in specialized truck epoxy marking application. epoxy heated prior spraying onto road surface. retroreflective glass beads applied using separate bead gun behind epoxy spray gun. typically, epoxy markings last 4 years.

epoxy has been in use since late 1970s , has gained popularity on 1990s technology has become more affordable , reliable. material competes directly plastic respect usage , cost.

negative impacts road surface

road surface raveling , potholes found exclusively along pavement markings

non-mechanical markers found contribute deterioration of asphalt concrete road surface courses. paint , tape markers can cause road surface crack, , in more severe cases, markers contribute road surface raveling (a process in aggregate particles dislodged road surface, causing surface texture become pitted , rough) or potholes.

this type of surface damage can found exclusively underneath pavement markings such lane markings , turn-lane arrows. there no definitive explanation of relationship between pavement markings , surface deterioration, there several hypotheses. 1 water vapor may have been trapped underneath road surface markings, causing de-bonding of asphalt binder aggregate materials. hypothesis reflectivity of markings may create differences in solar heating , thermal expansion strains between areas , without markings. small flaws caused differential strains may combined longitudinal cracks along markings. there surface treatments can make road surface less susceptible type of distresses, such slurry seals , stone mastic asphalt.

glass beads

glass beads composed of soda lime glass essential providing retroreflectivity in many kinds of road markings. retroreflectivity occurs when incident light vehicles refracted within glass beads imbedded in road markings , reflected driver s field of view. in united states, demand glass beads has led importing countries using outdated manufacturing regulations , techniques. these techniques include use of heavy metals such arsenic, antimony, , lead during manufacturing process decolorizes , fining agents. has been found heavy metals become incorporated bead s glass matrix , may leach under environmental conditions roads experience.

abrasion may dislodge these beads road marking itself, , reaction of these beads aqueous environment vastly accelerates decomposition , heavy metal release. during both routine road marking removal , harsh environmental conditions, these glass beads can degrade , leach incorporated heavy metals. there other, non-toxic metals can achieve same results. these may include zirconium, tungsten, titanium, , barium.