<p><p><figure id='attachment_3479' style='max-width:510px' class='caption aligncenter'><img class="wp-image-3479 size-full" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph showing a High Frequency Double Drum Vibratory Roller at Sakai SW 850." width="510" height="385" /><figcaption class='caption-text'> Sakai SW 850 High Frequency Double Drum Vibratory Roller (Scherocman et al. 2010).</figcaption></figure></p><p><div><h2><strong>Project Summary/Scope:</strong></h2>The project was located on a four-lane portion of California State Route 68 between Salinas and Monterey. The project consisted of a 75-mm thick overlay over an existing asphalt pavement surface. The test area was approximately 1.8 km in length and consisted of two travel lanes totaling 7.2 meters in width. One test section was on the outside driving lane and the second test section was on the inside passing lane.</p><p>Breakdown rolling was performed by using a 12,930 kg smooth dual-drum roller operated at a frequency of 4,000 vpm and amplitude of 0.33 mm. The same roller was used for finish rolling at a frequency of 2,500 vpm and amplitude of 0.33 mm. The frequency, amplitude, and speed settings were selected by the operator based on their past experience.<br><h2>Performance Monitoring:</h2>Density cores to determine percent Theoretical Maximum Density (TMD) after finish rolling.</p><p><u>Breakdown rolling:</u> Coverage map indicated non-uniform distribution of roller passes during breakdown rolling. Many roller passes were made close to the longitudinal joint and in the middle of the lane compacted to the outside (shoulder) edge of the lane. Temperature measurements showed variation between 60^o to 130^o C during compaction. The roller measured a values ranging from 30 MN/m² to 70 MN/m².</p><p><u>Finish rolling</u>: Finish rolling showed much better roller coverage than breakdown rolling, however, not as uniform as it should be. Temperature measurements showed variation between 50^o to 90^o C during the finish rolling process. The roller measured a values ranging from 30 MN/m² to 70 MN/m².<br><h2>Project Technical Paper:</h2>Scherocman, J., Rakowski, S., and Uchiyama, K. (2007). “Intelligent compaction, does it exist?” 2007 Canadian Technical Asphalt Association (CTAA) Conference, Victoria, BC, July.<br><h2>Date Case History Prepared:</h2>November 2012</p><p>&nbsp;</p><p></div></p></p>