305— Graded Aggregate Base

300-11 Section 305 — Graded Aggregate Base

305.1 Description 1 Construct an aggregate base course for a prepared foundation (subgrade or subbase). 305.2 Materials 1 When the Contract specifies a graded aggregate base course, the following base courses may appear on the proposal as alternat ives: • Macadam base course, • Marine limestone base course, or • Recycled Portland cement concrete base course. 2 When alternatives appear in the proposal, select the intended bid alternative and provide unit bid prices only on that alternative. 305.2.1 Macadam Base Course 1 Use base course material composed of crushed stone, excluding marine limestone, filled and bound with screenings obtained from an appropriate source listed on Qualified Products List 2. Ensure that the aggregate is free from vegetable matter, sand, lumps or balls of clay, or other deleterious matter. 305.2.2 Marine Limestone Base Course 1 Marine limestone aggregate is defined as any limestone aggregate not meeting the classification of dolomitic limestone. Fossiliferous limestone aggregate and recrystallized limestone aggregate are considered marine limestone aggregates. 2 Use l imestone base course materials produced from a single source or deposit that yields a satisfactory mixture conforming to all requirements and listed on Qualified Products List 2 as suitable for use in Marine Limestone Base. Ensure that the limestone base course does not contain clay, sand, organics, or other materials in sufficient quantity to be considered detrimental to the proper bonding, finishing, or strength of the base course. 305.2.3 Recycled Portland Cement Concrete Base Course 1 Use aggregate in the base course consisting of coarse aggregate of crushed, graded, recycled Portland cement concrete mixed together with sand, sand- gravel, soil, or other approved materials having similar characteristics and combined as necessary.