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60 TABLE 13 OHIO DOT's CHIP SEAL PERFORMANCE CRITERIA, 2002 Defect Severity Extent Surface Patterns Severe--light and heavy lines Greater that 40% of segment over the pavement surface length affected, continuous, or localized Bleeding/Flushing Moderate--excess binder on Greater than 5% of segment surface (loss of stone/tire length affected continuously contact) not subject to or total of 20% localized wearing off quickly problems Loss of Aggregate Moderate--patches of aggregate Greater than 10% of segment loss length affected continuously or total of 20% localized problems Source: Supplemental Specification 882, Chip Seal with Warranty 2002. Transverse joints have no more than 0.25 inch (6.5 mm) dif- Chapter four discusses performance risk distribution in chip ference in elevation across the joint as measured with a 6 foot seal contracts. This is extremely important in the context of this (2 m) straightedge. Chip seal edge is neat and uniform along the roadway lane, chapter, in that performance risk can be measured only by per- shoulder, and curb lines. formance indicators. As a performance indicator's measure- Chip seal edge has no more than 2 inches (50 mm) variance in ment grows more objective, the agency's capacity to enforce a any 100 feet (30 m), along the roadway edge or shoulder (Ohio DOT 2002). construction warranty increases. Therefore, the following best practices were identified from this chapter's analysis: PERFORMANCE CONCLUSIONS 1. An approved method, such as the sand patch method, AND BEST PRACTICES to measure chip seal macrotexture can furnish an objec- The performance of chip seals is affected by a variety of tively measured chip seal performance indicator. factors related to design, materials, and construction. The 2. The use of the chip seal deterioration model expressed literature review and survey results confirm that bleeding in the New Zealand P17 Specification will furnish an by far leads the predominant distress category. Therefore, objective definition of chip seal performance based on an effort needs to be made to quantitatively measure bleed- engineering measurements. ing and identify any means that can minimize it. Chip seal 3. The two aforementioned methods can be supplemented conditions deteriorate with age, and as such, measuring tex- with a continued visual distress rating based on the ture is a useful tool in developing a pavement condition index Ohio DOT's chip seal performance criteria, as shown for the seal. in Table 13.