TUBE AS 3658909 - Caterpillar

Establishing a Rolling Zone
As a rule, rolling should start immediately behind the paver. How close is determined by the mix composition and temperature of the mix. If lateral displacement occurs or the mix cracks, the operator is running too close. How far back does not matter providing densities are being obtained and the finish is satisfactory.This area is known as the rolling zone.Rolling Edge of Mat
1. If the mat has unconfined edges, the initial pass of the roller should be made on the outside (shoulder side) of the mat with the drums 152 mm (6 in) from the edge. This will help prevent the mix from pushing out.2. On the return pass, align the drums with the edge. The compacted pass will support the roller while the edge is being compacted. 3. If the outside edge is confined by a curb or gutter, the initial pass toward the paver should be run flush with the edge.Making Subsequent Passes
On the next pass and each subsequent pass of the roller, overlap the previous pass by 152 mm (6 in).If the inside of the mat is to be joined with another pass of the paver, leave about 152 mm (6 in) uncompacted until the next paver pass.If the inside edge is not to be mated, follow the same procedure as the outside edge and stay away from the edge on the pass toward the paver and roll flush with the edge coming away from the paver.Reversing Procedures
When approaching the paver, never reverse the roller abruptly. Before reversing, always turn off the vibration and steer the roller into a gradual arc until the machine is at a 45° angle to the paver. This will prevent a ridge in the mat that will be difficult to get out later.Rolling in Arcs
If space permits, such as airport projects, it may be better to work in arcs. This method permits all reversals to be done on the precompacted asphalt mix eliminating the chance of ridges. Care should be taken not to run the arcs over a crown.Rolling Zone Changes
Zone changes should only be made on previously compacted material. This rule should be followed when lining the roller up for the next pass and also when returning the roller to the starting point for the next rolling sequence.Rolling a Longitudinal Joint
1. Keep the roller primarily on the cold side of the mat. Overhang the drums onto the hot side by about 152 mm (6 in). This will pinch the hot mix into the joint.2. Both drums should be run with the vibratory system OFF (static).3. The reverse pass should be made in the same position. 4. On the next pass and initial pass on the hot mat overhang the drums about 125 mm (6 in) on the cold side and run with both drums vibrating.Rolling a Crown
When rolling a crown, always work from the downside first. On the inside or top passes, overhang the drum by about 152 mm (6 in) on both sides of the