Pass the Test
It's worth repeating that a properly conducted test strip can form the basis of an effective rolling pattern. The key is to treat the test strip as a microcosm of the entire paving application. What is learned during the test strip should translate directly to the rolling pattern.

To begin measuring a test strip, mark out a section of the mat when production begins. The next step is to build a pass-density pattern with the breakdown roller. Following each pass with this roller, an onsite density test should be conducted. This eventually establishes a growth curve, showing the amount of density achieved after each pass and clarifying when the pneumatic roller should take over.

For example, consider that the density requirement of a particular job is 93 percent to achieve a 100-percent pay factor. While rolling the test strip, the paving foreman instructs the breakdown roller operator to make four passes over the mat with a double-drum vibratory roller, taking a density measurement after each pass. The following results are recorded: