Once the placement of hot-mix begins, it is important to consider the overall length of time and seasonal weather conditions that may occur prior to placement of the SMA (surface) lift to ensure surface water is not trapped in the structure through low density joints or segregation. Strict enforcement of density provisions in the applicable HMA specifications and considerations for use of positive drainage (edge drains) should be made. Where scheduling/traffic control plans prevent the SMA surface from being placed for extended periods of time, placement of a seal coat should be considered as an interim driving surface to minimize trapped moisture.

Detailed perpetual pavement design construction considerations are available through this

link

.