December 8th, 2012
ROCKY ROADSPreserve Infrastructure, by Catherine Higgins.
Why do asphalt roads deteriorate? Sometimes the causes of road deterioration are easy to determine and sometimes the causes can remain a bit of a mystery.
Some common causes of deterioration include:
Traffic – heavy truck and automobile traffic causes wear and rutting over time.
Water – water that seeps under the pavement and makes the earth underneath soft. The freeze-thaw cycle causes damage when water seeps into the pavement, freezes and expands, then melts. Over time, the freeze-thaw cycle can break pavement.
Erosion – water can erode slopes and excavate under roads causing indentations and cracking.
Time and sunlight – UV light ages asphalt over time.
Pavement preservation techniques, including surface treatments like slurry sealing, crack sealing, micro surfacing, and help preserve asphalt roads.
One less known cause of pavement deterioration is pavement markings. A UDOT Research project looked at 13 areas around the state, where pavement markings and deterioration had occurred together, to determine if the markings caused deterioration.
Researchers carefully examined each area, making note of all distresses. Pavement markings were found to be significant contributors to pavement deterioration in some cases.
Researchers theorize that water vapor condenses underneath the paint leading to damage to the pavement in the form of raveling or de-bonding. Cracking near the pavement markings also seem to indicate that paint causes stresses that cause cracks that can lead to more damage. Laboratory tests have not yet confirmed the theories.
Selecting the right preservation treatment for the right pavement condition, along with proper production and placement helps eliminate the deterioration that seems to be caused by pavement markings. UDOT has discontinued the use of some pavement treatments that allows water vapor to become trapped between paint and the pavement surface.