Admin Order 58-16-01 - Laserfiche WebLink

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Bituminous treated base (BTB) 0.22 *Layer coefficient for ICTB maybe used whereat least 50 percent, by weight, of the existing material to be treated is granular. Surface Course coefficient, all lifts (al) Plant mix AC 0.42 Minimum Thickness — Should the pavement design result in a thickness less than shown in the table below, the minimum AC pavement thickness required shall be as shown below: Street Classification Minimum Thickness Local or Neighborhood Collector 6 inches Local or Neighborhood Collector w/bus route 8 inches Major Collector 8 inches Arterial 9 inches Round pavement thickness calculations up to the nearest half-inch (0.5"). The minimum AC thickness for Local and Collector streets listed above may be decreased by up to two inches (as calculated using the layer coefficients above) if ICTB or CTB (place CTB on subgrade fabric) a minimum of 10 inches thick with a 7 day strength of between 300-500 psi is constructed as a base layer for the AC. Treated subgrade, ICTB, or a layer of aggregate subbase or base material or cement treated base over subgrade geotextile shall be included under the pavement section in the construction plans as a working platform for construction in the following situations: 1. Where soils testing has been performed and one or more of the following conditions apply: a. The report indicates that the soils are weak,• and/or b. The report states the soils will not be compactable to Standard Specifications requirements; and/or c. The report states the soils will be prone to pumping during the construction period; and/or d. The subgrade soils do not meet compaction and/or deflection requirements during construction. 2. Where the designer has not performed soils testing and has assumed soil strength R=5 (or Mr = 3775) for design purposes. Public Improvement Design Standards Manual, 2016 Page 2-33