The subbase is the improved layer constructed on the prepared subgrade below the pavement.
(A) Construction specifications. Where granular subbase is required, the subdivider/developer shall use “subbase granular material, Type A,” conforming to Section 311 - Granular Subbase of the IDOT Standard Specifications except as otherwise noted.
(B) When constructing the subbase, if a soft spot in the soil subgrade is discovered, it shall be undercut to remove the unsuitable soft or spongy areas to the satisfaction of the city. The excavation shall be backfilled with CA-1 aggregate to bring the subject area back up to the subgrade elevation.
(C) To avoid segregation, a suitable spreader box or paver shall be used to place granular subbase.
(Ord. 2009-21, § 18.5-3-14, passed 10-5-2009; Am. Ord. 2016-29, passed 11-7-2016)