The best sealer for your application will depend on location
and whether or not the pavement is a good candidate for crack sealing
Sealant is subjected to the extreme high and low temperatures. The product install will be exposed to the high and low pavement surface temperatures at the site.
Warmer climates require a material that is stiffer to resist flow and tracking, whereas cooler climates require a softer material for flexibility to prevent the sealant from cracking/splitting or de-bonding during expansion and contraction of the pavement.Ā A sealantās performance is controlled by the relationship and interactions of the low temperature, high temperature, and adhesive and elastic properties over the entire range of temperatures and strains experienced.
To help identify the climate conditions in a specific area, The Long Term Pavement Performance (LTPP) program is part of the Strategic Highway Research Program (SHRP) which investigates specific pavement-related details that are critical to pavement performance. One tool of LTPP aides in the selection of sealants based on the climate and pavement temperature it in which it is going to be used.Ā The FHWA-LTPP-BIND process can be used to determine the expected temperature ranges that will be present. The process determines the high and low temperature extremes for most locations in the US and Canada, and is used as the basis for selecting asphalt cement grades for hot mix asphalt concrete pavements. The same process can be used to determine the temperatures that sealant materials will be exposed to and will need to function within.Ā For the website of the “LTPP Pavement Maintenance Materials: SHRP Crack Treatment Experiment, Final Report” andĀ information, please go to:Ā http://www.fhwa.dot.gov/pavement/pub_details.cfm?id=133.
Pavement Condition:Ā Even if sealant is perfect for the application, failure will occur if the pavement is deteriorating, raveling or unstable. Other factors contributing to pavement condition are:
Pavement Type: Itās important to determine if the type is asphalt, concrete or composite: concrete with asphalt overlay.
Crack Types: The key focus is the expected movement based on crack typeāthe sealant selected must accommodate the anticipated pavement movement.
Crack Width:Ā Wider cracks reduce the percentage of movement which can help the sealant stay bonded better, more so than narrow cracks.
Crack Spacing: The wider the spacing between cracks, the greater amount of movement will be generated with temperature changes. Cracks that are spaced closer together will have less movement.
Future Maintenance: For overlays, make sure product is recessed in the cracks; no material on surface.
Surface treatments: Make sure the material is not too soft to bleed through chip or slurry seal.
Traffic Load: Highway high-speed sealant spends less time under traffic vs parking lots where vehicles sit and turn on the sealant. Slower traffic will need a stiffer, more trafficāresistant material.
Maintenance Methods: Material that goes down in an overband, needs to be able to shear off or resist equipment like snow plows or other maintenance activities.
Slopes/Super Elevation: It can be better to have a higher viscosity type of sealant than lower in sloped locations so that the material resists flow out of the end of the crack due to elevation.
For the entire Constructions Pros.com article, please go to:Ā http://www.forconstructionpros.com/pavement-maintenance/preservation-maintenance/cracksealing-equipment-materials/article/20863051/how-climate-and-pavement-condition-determine-sealer-selection.