16.3.2 PAVERS
The HMA is placed and compacted to a certain degree with the paver (Figure 16.13). The paver
is wheel, rubber, or steel-track mounted and consists of a hopper to receive the material from the
truck or a material transfer vehicle, conveyors to send the material at the back, augers (with available
extensions) to distribute the mix transversely across the width of the pavement, and a screed
(often heated and capable of vibrating, and with extensions), which ensures a specific depth of the
material and preliminary compaction. Paving widths with available equipment can range from 8 to
48 ft. Grade control is usually done with a stringline/mobile ski, sonic/laser, as well as GPS system.
Recent developments in paver technology include the use of variable speed engine to save fuel and
reduce noise whenever possible, specially designed pipes to remove heat and exhaust from the crew,
better turning capability, design of paver components to reduce the chance of segregation of the
mix, and redesign of the paver to improve operator visibility.