658.01 Description. This work consists of furnishing and placing the necessary aggregate and tile for the protection and aeration of the roots of trees and shrubs.
658.02 Materials. Furnish aggregate for tree root aeration and protection consisting of No. 4 or 467 limestone or gravel with a maximum sodium soundness loss of 15 percent.
Furnish 4-inch (100 mm) pipe conforming to 603 Type E conduit. Furnish embankment conforming to Item 203.
658.03 Preparation. The feeding root area to be protected and aerated is the ground surface area lying within the periphery of the tree or shrub not marked for removal. Prepare these areas by excavate all vegetation, wood, brush, and debris.
658.04 Aeration for Trees Not Welled. Where the earth fill is less than 12 inches (300 mm) and more than 4 inches (100 mm) over the feeding root area, loosely spread an aggregate aeration course of one-half the height of fill, but not less than 3 inches (75 mm), over this area. At the tree trunk, increase the thickness to the height of the fill and extend it outward from the tree trunk in collar form for a distance of 15 inches (0.4 m). Place a 2-inch (50 mm) layer of straw or hay over the aggregate.
658.05 Aeration with Tree Wells. Place an aeration course of aggregate while constructing the tree wells and before any other filling. Do not place any aggregate inside the tree well (between the wall and the tree trunk). Place the aggregate over the entire feeding root area outside of the tree wells to a total depth of 6 inches (150 mm) for each 12 inches (300 mm) of earth fill, or proportion thereof, but place a minimum depth of 6 inches (150 mm) regardless of depth of overlying fill. Place a 2-inch (50 mm) layer of straw or hay over the aeration layer.
658.07 Method of Measurement. The Department will measure Tree Root Aeration by the number of cubic yards (cubic meters), measured in the carrier or truck according to 109, of the aggregate furnished, placed, completed, and accepted.
The Department will pay for accepted quantities at the contract price as follows:
Item unit Description
Yard Tree Root