(A) Prior to construction of any base or subbase, the subbase shall be scarified and compacted to a minimum depth of 6 inches. Compaction shall be a minimum of 95% density.
(B) Base course shall consist of a minimum depth of 6 inches of Aggregate Base Course (ABC) or Mineral Aggregate (MA) compacted to a minimum of 95% density. The ABC or MA shall be shaped to the width and cross slope of the approved typical section. Placement of any select material and minimum depth requirements shall be approved by the Road Department. The ABC shall meet the following gradation specifications:
GRADATION SPECIFICATIONS | |||
Percentage by Weight Passing Sieve | |||
Sieve Sizes (Square Openings) | Select Material | Aggregate Base | |
Type A | Type B | ||
GRADATION SPECIFICATIONS | |||
Percentage by Weight Passing Sieve | |||
Sieve Sizes (Square Openings) | Select Material | Aggregate Base | |
Type A | Type B | ||
3 inches | 100 | ||
1-1/2 inches | 100 | ||
1-1/8 inches | 100 | ||
No. 4 | 30–75 | 30–70 | 38–65 |
No. 8 | 20–60 | 20–60 | 20–60 |
No. 30 | 10–40 | 10–40 | 10–40 |
No. 200 | 0–12 | 0–12 | 3–12 |
P.I. Maximum | 5 | 5 | 5 |
(C) All materials in the subbase or base course shall be placed using moisture and density control in accordance with good engineering practice and approval by the Road Department. Prior to the acceptance of roads for maintenance by the town, the contractor shall provide the town with engineering certifications of materials used and density testing.
(D) A dust free surface consisting of tack or prime coat penetrant asphalt and at least a single coarse bituminous surface treatment shall be provided. The Road Department shall have the authority to approve or disapprove the design of the dust free surface and structural section (base/subbase).
(E) (1) Engineering calculations shall be submitted for all drainage required such as but not limited to:
(a) Natural watercourses;
(b) Subgrade;
(c) Side ditches;
(d) Surface runoff; and
(e) Culvert sizes.
(2) Minimum cross culverts shall be 18 inches diameter. Minimum driveway culverts shall be 12 inches diameter.
(F) All computations and certifications required shall be performed and sealed by an engineer licensed to practice by the Arizona State Board of Technical Registration.
(G) (1) The typical section minimum roadway for residential and collector streets shall be:
(2) Notes:
(a) ABC material shall be compacted to 95% density.
(b) All driveways shall have minimum 12 inches C.M.P. where roadway ditch evidenced.
(c) Maximum grade within 100 feet from intersection = 4%.
(d) Cross culverts for existing water courses shall be 18 inches minimum. Culvert size calculations shall be required.
(e) Structural section to be determined by good engineering practice.
(2001 Code, § 7-11-3)