Polyurea
Polyurea markings are a sprayed, two-component durable pavement marking material that is relatively new to the pavement marking market. Various formulations of polyurea markings exist on the market and are available from a number of vendors. Polyurea pavement markings have been used on an experimental basis by TxDOT.
Polyurea materials are marketed as durable pavement markings that provide exceptional color stability, resistance to abrasion, and adhesion to all pavement surfaces. Polyurea markings appear to be less sensitive to pavement surface moisture than thermoplastics and can be applied at temperatures as low as freezing. Most of these materials are marketed as fast curing materials, achieving proper bonding and no-track conditions in 2 minutes or less. Polyurea markings have been reported to have service lives of up to 5 years, although limited data exist to support this statement.
One of the drawbacks associated with polyurea materials is that some must be applied by a special striping apparatus, which limits the number of contractors available to apply the material. Other polyurea materials, however, can be applied by a standard epoxy truck. The type of truck required is based on the resin-catalyst mix ratio. Polyurea mixes with a 2:1 mix ratio can be applied with a standard epoxy truck. Table 2-14 summarizes the recommended uses of polyurea pavement markings.
- | Asphalt | Concrete | Surface Treatments | ||||||
|---|---|---|---|---|---|---|---|---|---|
- | AADT <1,000 | AADT 1,000 –10,000 | AADT >10,000 | AADT <10,000 | AADT 10,000 –50,000 | AADT >50,000 | AADT <1,000 | AADT 1,000 –10,00 0 | AADT >10,000 |
Use 2 | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Thickness | 15–25 mils | 15–25 mils | 15–25 mils | ||||||
Surface prep. | Remove existing markings, clean, & dry | Remove existing markings, clean, & dry | Remove existing markings, clean, & dry | ||||||
Expected service life | Up to 4 years | Up to 4 years | Up to 3 years | Up to 4 years | Up to 4 years | Up to 3 years | Up to 4 years | Up to 4 years | Up to 3 years |
Approx. bid price (per lf) | $1.00 | $1.00 | $1.00 | ||||||
Estimated cost per year of service life (per lf) 3 | $0.25 | $0.25 | $0.33 | $0.25 | $0.25 | $0.33 | $0.25 | $0.25 | $0.33 |
Footnotes: 1. The cost and performance of polyurea is based on limited experimentation both in Texas and nationwide. 2. Y = suitable for use. 3. Prices include a proprietary retroreflectivity-enhancing ceramic element embedded into the marking surface. Polyurea materials applied without the proprietary ceramic element may be less expensive. | |||||||||