Going Beyond the Pre-Activity or Pre-Paving Meeting
The Paving Superintendent is responsible for the individual crew members while monitoring plant production vs. amount and speed of hot mix being delivered. However, the inspectors responsible for the ACP operations should get to know the principal members of the contractor's paving crew−the screed operator and the person taking cores and profiles−and determine their experience level and role in the operations. If possible, find out the experience level of the roller operators, especially the break-down roller operator. They are key parts of attaining a quality hot mix surface.
The screed operator is probably the most important person in the paving train. He sets the grade control and establishes flow gates, tow points, and auger settings. He will need to maintain the paver speed at 60 feet per minute or less to prevent mat irregularities caused by an erratic tow point. He will be matching any longitudinal joints when placing against an existing mat and setting the height of the end gate relative to the existing mat. It is very important for the inspector to discuss these things before and during the placement operations. The inspector should watch when adjustments are being made and try to understand from him why they are needed.
The contractor's 1B person should keep control of the rollers, monitor mix temperature variations, and visually check the mat for segregation, dryness/wetness (lack of or too much asphalt), and longitudinal joint compaction. The inspector should also watch this person closely to see that all items are being covered and talk to him/her frequently about their observances.
Even though today a results-oriented specification puts the quality burden on the contractor, the inspectors should not solely rely on the contractor or on future test results to attain good quality. Hot mix repairs, especially on a surface course, can be difficult, time-consuming, and detrimental to the aesthetics of a finished project. Visual inspection and frequent communication by all parties during the operations are essential to making sure all aspects of the hot mix operation lead to a superior quality product.
Ride quality tip
Smoothness and consistency of longitudinal joints are not reflected in the IRI results by the inertial profiler. The end gate of the paver should be kept above the adjacent mat joint ½” to 1” to help ensure good joint smoothness and compaction.