Placement and Compaction
Screed Width
Placement
In addition to paver speed, screed width and lift depth, longitudinal joint temperatures can significantly affect productivity. If conditions are favorable (high production, short distance to pave in one night, hot air and surface temperatures) adjacent pulls by the same paver could be close enough together to qualify the longitudinal joint as a “hot joint” as defined by the Unified Facilities Guide Specification (175°F or hotter) and the FAA specification (160°F or hotter). Hot joints require no further preparation while cold joints must be treated (usually cut back to a straight vertical edge), which requires time.
Although Advisory Circular 150/5370-13 states that paver screed widths of 25 ft are preferred, widths beyond the typical 12 ft (See Image) are not likely except in larger paving markets.
Compaction
Lower nighttime temperatures mean less time available for compaction before the HMA cools to cessation temperature. A straightforward computer program, MultiCool, that can predict time available for compaction is available from the following websites:
