Void Reducing Asphalt Membrane
a.k.a. Longitudinal Joint Sealant
Everyone knows there is a need for longitudinal joint improvement. The longitudinal joint crack forms because the first paving pass creates an unconfined edge. Rollers can’t compact the edge to the same density as the interior of the mat. Then air and water intrudes into the HMA at the construction joint and damages the pavement over time. This causes premature construction joint failure and triggers maintenance or reconstruction.
A Void Reducing Asphalt Membrane (VRAM) otherwise known as a longitudinal joint sealant (LJS) is placed in the form of a heavy membrane under the intended area for an overlay construction joint, either 12” or 18” wide and with thickness up to 5/32”. The longitudinal joint sealant then migrates into the high air voids in the HMA overlay in the area of the longitudinal construction joint and reduces voids to more typical HMA range.
- During construction
- Upward migration
- Resist Flow
- Crack resistance
- Reduces water and air permeability
- Bonds to existing pavement