208 SUBGRADE PREPARATION
From MDOT Policy Manual
- Prepare, protect, and maintain the subgrade prior to the construction of succeeding courses.
- After roadway excavation and embankments are completed in conformance with Section 204, fine grade and compact the subgrade to at least 97 percent of the maximum dry density per T 180.
- 208.03.01 Removal and Replacement of Unsuitable Material. Remove and dispose of all soft and unstable material and any other portions of the subgrade that will not properly compact. Replace with suitable material and compact.
- 208.03.02 SubgradeThe top surface of a roadbed upon which the pavement structure, shoulders, and curbs are constructed. Control. Bring the subgrade surface to line and grade and shape it to the specified cross section. Set grade for subgrade control both longitudinally and transversely with fixed controls not exceeding 25 ft spacing. Limit the finish subgrade deviation to ½ in. from the established grade. Compact and smooth the subgrade over its full width by the use of an approved smooth faced, steel-wheeled roller approved by the EngineerAny person designated by the Administrator or the procurement officer, acting directly or through his duly authorized representative, such representative acting within the scope of the particular duties assigned to him or of the authority given him.. Use mechanical tampers and vibratory compactors if rolling is not feasible.
- 208.03.03 Bleeder Ditches. Maintain adequate open bleeder ditches along the subgrade at all times to keep it thoroughly drained. Maintain erosion and sediment control practices as specified in Section 308.
- 208.03.04 SubgradeThe top surface of a roadbed upon which the pavement structure, shoulders, and curbs are constructed. Maintenance. Prevent damage by heavy loads or equipment. Repair or replace any defects or damage.
- 208.03.05 SubgradeThe top surface of a roadbed upon which the pavement structure, shoulders, and curbs are constructed. Approval. Do not place subsequent cover material upon a frozen subgrade or any subgrade until it has been checked and approved.
208.04 MEASUREMENT AND PAYMENT.
- SubgradeThe top surface of a roadbed upon which the pavement structure, shoulders, and curbs are constructed. preparation, including bleeder ditches and any mechanical tamping will not be measured but the cost will be incidental to the pertinent items specified in the Contract DocumentsThe written agreement executed between an Administration and the successful bidder, covering the performance of the work and furnishing of labor, equipment and materials, by which the Contractor is bound to perform the work and furnish the labor, equipment and materials, and by which the Administration is obligated to compensate him therefore at the mutually established and accepted rate or price. The Contract Documents shall include the Invitation for Bids, Notice to Contractors, Instructions to Bidders, Proposal, Contract Forms and Bonds, General Provisions, Specifications, Supplemental Specifications, all Special Provisions, all Technical Provisions, all Plans and Notices to Proceed, also any written Change Orders and Supplemental Agreements that are required to complete the construction of the work in an acceptable manner, including authorized extension thereof.