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48 TABLE 32 MICROSURFACING ROLLER REQUIREMENTS BY AGENCY Specification Content Roller Requirements U.S./State Canada/Province Analysis/State Static Steel 1/NC 0 1/AL Pneumatic Tired 7/AL, NC, NV, NY, 1/NS 4/AL, OK, PA, VA OK, PA, VA Combination 1/NC 2/NS, QB 0 Pneumatic/Steel No Rollers Specified 17 5 13 10-ton (maximum) pneumatic tire roller equipped with a water SUMMARY spray system. All tires should be inflated per manufacturer's specifications. Rolling shall not start until the microsurfacing has Good microsurfacing products are impossible without well- cured sufficiently to avoid damage by the roller. Areas which require rolling shall receive a minimum of two (2) full coverage calibrated and well-functioning equipment. Because micro- passes (ISSA 2010b). surfacing is an equipment-intensive activity, special attention is necessary for the machines that will ultimately make micro- The Quebec MOT added an interesting comment to its surfacing a profitable pavement maintenance and preserva- answer to this question when it stated it only uses rolling to tion tool. The next chapter will focus on how to employ the "accelerate the curing period." A follow-up revealed that tools and techniques of this and previous chapters to produce the agency believes that because rolling promotes embed- a high-quality microsurfacing product. The following effec- ment that the road can be opened to traffic earlier than tive practices were identified in this chapter: without rolling. This appears to run parallel to the ISSA rec- ommendation that "airports and parking areas should be rolled . . ." Presumably, the purpose is to promote greater 1. Requiring a test strip of 500 to 1,000 ft (152.4 to embedment or adhesion and thus at an airport rolling would 304.8 m) in length be constructed and accepted allows reduce the amount of foreign, objects, and debris (FOD) that the agency and the contractor to ensure that the equip- could damage a jet engine. Parking lots are low-volume facil- ment is properly calibrated and that any workmanship ities and hence will not experience as much traffic com- issues are resolved before full-scale microsurfacing paction as a road, making rolling desirable. Going any deeper production. If the microsurfacing is scheduled to occur into this question is beyond the scope of this report; however, after dark, the test strip is to be constructed after dark. it does beg the question of whether or not rolling has any 2. It is important that a microsurfacing placement machine impact on microsurfacing performance, and hence makes a be recalibrated every time there is a change in material good area in which to conduct future research. source or composition.