Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/142598
– saved the county $109,000, compared to conventional conveys recycled asphalt pavement back to a self-contained, hot mix. At Upper Big Tujunga Canyon Drive, a much larger closed-circuit asphalt recycling plant, which is towed by the project (approximately 135,000 square yards), the county milling machine. For this project, PRS used a CRMX 2 cold estimates that the CIR treatment saved $1.2 million comrecycling plant made by Nesbitt Contracting of Arizona. pared to hot mix asphalt. In California, all recycled asphalt is required to meet a speTwo of L.A. County's cold recycling projects used cold cific gradation requirement of 100-percent passing a 1-inch central plant recycling (CCPR); on those projects, PRS used a screen. The recycling plant has a screen deck that vibrates as the RAP passes over the screen. Oversize material goes through a vertical impact crusher and is returned to the top of the screen deck where the material is rescreened. The process continues until all of the RAP is sized to meet the required gradation, says James Emerson, project developer with Pavement Recycling Systems. Once through the screen, the RAP loads onto a conveyor belt equipped with a weigh bridge that continuously weighs the material and streams the weight information to a computer. From there, the RAP travels through a dual-shaft pugmill for mixing with an engineered emulsion. Using software developed by Nesbitt, the recycling plant Cox Rolling Thin Film Oven computer meters the application of the emulsion based on the weight of the RAP delivered to the pugmill to rejuvenate the asphalt. In the case of Altadena Drive, the CRMX 2 recycling unit added a designed percentage of PASS-R emulsion made by Western Emulsions. The now recycled asphalt is discharged from the pugmill into a windrow underneath the recycling unit. A windrow pickup machine and a Caterpillar AP 1055 Stainless Steel Sieves Gilson Rotary Sifter tracked asphalt paver follow close behind to pick up and place the recycled asphalt in a 3- to 4-inch pavement mat. The laydown operation is followed by compaction with a 12-ton Caterpillar double steel drum asphalt roller and a 25-ton BOMAG Gilson Company, Inc. is pleased to offer our products along with all of James pneumatic roller operating in series. To Cox & Sons' products. Whatever your needs, we've got you covered. cap the recycled asphalt at Altadena Drive, L.A. County elected to place a 1.5-inchthick layer of rubberized hot mix asphalt as a wearing course. Kelley estimates that the CIR process at Altadena Drive – not a major project (approximately 10,000 square yards) need it We've got you covered. 800.444.1508 / www.globalgilson.com Text INFO to 205-289-3789 or visit www.betterroads.com/info Better Roads July 2013 7 HighwayCon_BR0713.indd 7 6/26/13 4:42 PM