3-1 DIVISION 3 - BASES Section 301. Subbase ....................................................................................... 3-3 Section 302. Aggregate Base Course ............................................................... 3-4 Section 303. Open-Graded Drainage Courses .................................................. 3-8 Section 304. Rubblizing Portland Cement Concrete Pavement ...................... 3-14 Section 305. HMA Base Crushing and Shaping .............................................. 3-19 Section 306. Aggregate Surface Course and Maintenance Grav el ................. 3-22 Section 307. Aggregate Shoulders and Approaches ....................................... 3-26 Section 308. Geosynthetics for Base .............................................................. 3-30 3-2 NOTES 3-3 Section 301. Subbase
301.01 Description
This work consists of constructing a granular subbase on a surface approved by the Engineer.
301.02 Materials
Provide material in accordance with the following section: Granular Material Class II ..................................................................... 902
301.03 Construction
Spread the subbase material evenly and compact to at least 95% of the maximum unit weight, at a less -than-optimum moisture content, for its entire thickness. Place the subbase in layers no greater than 18 inches. Where the required depth is more than 18 inches, place the material in layers of equal thickness. Construct the subbase to plan grade within a tolerance of plus 1 inch. Do not place subbase on frozen, soft, unstable, or rutted subgrade. If subbase material becomes mixed with subgrade material, remove, dispose of, and replace the subbase material at no additional cost to the Department.
301.04 Measurement and Payment
Pay Item Pay Unit Subbase, LM ................................................................................... Cubic Yard Subbase, CIP .................................................................................. Cubic Yard
A.Subbase, LM. The Engineer will measure Subbase, LM based on hauling unit dimensions and load count before placement and compaction. The unit price for Subbase, LM includes the cost of providing, hauling, placing, compacting, and grading the material.
B.Subbase, CIP. The Engineer will measure Subbase, CIP by the staked-section method as described in subsection 205.04. The unit price for Subbase, CIP includes the cost of providing, hauling, placing, compacting and grading the material.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 176–178 of 1,146.