As chip sealing operations have begun throughout the state, the Missouri DOT (MoDOT) wants drivers to know what the work entails and why this technique is used to preserve highways throughout the state.
“The bottom line is that chip sealing is a cost-effective way to get more use out of our highways,” Natalie Roark, MoDOT’s state maintenance director, said in a statement.
MoDOT says a chip seal operation entails spraying a heated film of asphalt liquid on the road, followed by placing fine rocks or chips on top. The chips are then compacted to make them adhere to the roadway. Finally, the excess loose chips are swept from the surface, leaving an improved roadway that will hold up longer than it would have without the treatment.
Chip seals are about one-third the cost of a conventional asphalt overlay, averaging $15,000 per mile as compared to an estimated $55,000 per mile for an asphalt overlay. Chip seals keep damaging water from penetrating paved surfaces and extend the life of the pavement for an additional five to seven years. Chip sealing also seals cracks and improves roadway traction.
A surface may be chip sealed several times, providing the road remains structurally sound. The chip seal process is typically used on roads carrying lower traffic volumes which make up more than half of MoDOT’s roadway network.
The videos on the department's chip sealing operations can be found on MoDOT Central District’s YouTube channel here.
SOURCE: Missouri DOT