Why do chip seals fail?

Oil and stone, more properly known as a chip seal, fail for a variety of reasons but, more often than not fail when the stone does not properly adhere to the pavement. This stone loss is most commonly a result of a misstep in the initial installation.

Installation factors that can attribute to stone loss include:

• Applying the treatment in the wrong weather
• An improper emulsion application rate
• An improper aggregate application rate
• Placing the aggregate too late and after the emulsion has broken
• Dirty aggregate

Aside from timing and application rates, there are five steps that should be taken during the construction process:

• Sweeping before the emulsion application
• Spraying the emulsion
• Spreading the aggregate
• Rolling the aggregate
• Sweeping the excess stone off of the road surface a day or two after the chip seal is placed.

References

Pavement Cracking: A Failure Indicator of Your Roads
NYSLTAP-CLRP Quick Answer

Pavement Maintenance
NYSLTAP-CLRP Workshop Manual

June, 17'