mon Excavation" if the latter classification is included in the proposal, or as “Borrow" when this classification is included in the proposal. BASIS OF PAYMENT 152-4.1 UNCLASSIFIED EXCAVATION. This item will be paid for at the contract unit price per cubic yard for "Unclassified Excavation," which price and payment shall be full compensation for the removal and satisfactory disposal of all excavation regardless of material encountered, necessary in the preparation, construction, and completion of the project; for the removal of stockpiles; for formation, watering, and compaction of embankments; for preparation and completion of the top portion of the subgrade; for final dressing of the surfaces and slopes in accordance with the plans; and for furnishing all labor, equipment, tools, and incidentals necessary to complete this item. 152-4.2 COMMON EXCAVATION. This item will be paid for at the contract unit price per cubic yard for "Common Excavation," which price and payment shall be full compensation for the removal and satisfactory disposal of all excavation not included in "Solid Rock Excavation," necessary in the preparation, construction, and completion of the project; for the removal of stockpiles; for formation, watering, and compaction of embankments; for preparation and completion of the top portion of the subgrade; for final dressing of the surfaces and slopes in accordance with the plans; and for furnishing all labor, equipment, tools, and ïncidentals necessary to complete this item. 152-4.3 SOLID ROCK EXCAVATION. This item will be paid for at the contract unit price per cubic yard for "Solid Rock Excavation," which price and payment shall be full compensation for the removal and satisfactory disposal of boulders, detached rock, and of all rock in ledges or masses, necessary in the preparation, construction, and completion of the project; for incorporation of boulders or rock in embankments and on fill slopes; for final dressing of the surfaces and slopes in accordance with the plans; and for furnishing all labor, equipment, tools, and incidentals necessary to complete this item. 152 4.4 BORROW EXCAVATION. This item will be paid for at the contract unit price per cubic yard for "Borrow Excavation,” which price and payment shall be full compensation for the furnishing and placing of the material; for formation, watering, and compaction of embankments; for preparation and completion of the top portion of the subgrade; for final dressing of the surfaces and slopes in accordance with the plans; and for furnishing all labor, equipment, tools, and incidentals necessary to complete this item. Payment will be made under: Item P-152-4.1 Unclassified Excavation-per cubic yard. ITEM P-153 WATERING DESCRIPTION 153-1.1 This item shall consist of furnishing and applying water required in the compaction of embankments, subgrades, subbases, base courses, and for other purposes in accordance with the requirements of these specifications, or as directed by the engineer. CONSTRUCTION METHODS 153-2.1 Water, when required, shall be applied at the locations, in the amounts and during the hours, including nights, as directed by the engineer. An adequate water supply shall be provided by the contractor. The equipment used for watering shall be of ample capacity and of such design as to assure uniform application of water in the amounts directed by the engineer. METHOD OF MEASUREMENT 153-3.1 The units of watering to be paid for (subject to 4.1) shall be the number of 1,000-gallon units of water, measured in the vehicle at the point of delivery on the airport, and used as ordered. BASIS OF PAYMENT 153-4.1 When the bid schedule contains an estimated quantity for any one of the items below, the units measured as provided above shall be paid for at the contract unit price per 1,000-gallon unit for watering of embankment, watering of subgrade, watering of subbase, or watering of base course, as the case may be, which price and payment shall be full compensation for furnishing, hauling, and placing; and for all labor, equipment, tools, and incidentals necessary to complete the item, including the furnishing of water plants if necessary. When the bid schedule does not contain an estimated quantity for any one of the above items, the performance of these items shall be considered as a subsidiary obligation of the contractor covered under pay items involved in the contract and no allowance shall be made for providing or maintaining a water plant. Payment will be made under: Item P-153-4.1 Watering-per 1,000-gallon unit. 154-1.1 This item shall consist of a subbase course composed of granular materials constructed on a prepared subgrade or underlying course in accordance with these specifications and in conformity with the dimensions and typical cross section shown on the plans and with the lines and grades established by the engineer. MATERIALS 154-2.1 MATERIALS. The subbase material shall consist of hard durable particles or fragments of granular aggregates mixed or blended with fine sand, clay, stone dust, or other similar binding or filler materials, produced from approved sources to provide a uniform mixture complying with the requirements of these specifications as to gradation, soil constants, and capability of being compacted into a dense and stable subbase. The material shall be free from vegetable matter, lumps or excessive amount of clay and other objectionable or foreign substances. Pit-run material may be used, provided the material meets the requirements specified. TYPE A SUBBASE (10-inch frost penetration or greater) 3-inch Sieve designation Percent passing 100 Not more than 70 The material passing the No. 10 mesh sieve shall meet the following requirements: If more than forty-five (45) percent of the entire sample is retained on the No. 10 mesh sieve, the amount of material passing the No. 200 mesh sieve may be increased to twenty-five (25) percent if Liquid Limit and Plasticity Index are not increased. The material passing the No. 10 mesh sieve shall meet the following requirements: If more than forty-five (45) percent of the entire sample is retained on the No. 10 mesh sieve, the amount of material passing the No. 200 mesh sieve may be increased to forty-five (45) percent if Liquid Limit and Plasticity Index are not increased. CONSTRUCTION METHODS 154-3.1 GENERAL. The subbase course shall be placed where designated on the plans or as directed by the engineer. The material shall be shaped and thoroughly compacted within the tolerances specified. The granular subbases, which due to grain sizes or shape, are not sufficiently stable to support without movement the construction equipment, shall be mechanically stabilized to a minimum depth of three (3) or four (4) inches of the top layer as directed by the engineer. The mechanical stabilization shall include the addition principally of a fine grained medium to bind the particles of the subbase material sufficiently to furnish a bearing strength so that the course will not deform under the traffic of the construction equipment. The addition of the binding medium to the subbase material shall not increase the soil constants of that material above the limits as shown. 154-3.2 OPERATION IN PITS. All work involved in clearing and stripping pits and handling unsuitable material encountered shall be performed by the contractor at his own expense. The subbase material shall be obtained from pits or sources that have been approved. The material in the pits shall be excavated and handled in a manner that a uniform and satisfactory product shall be secured. 154-3.3 EQUIPMENT. All equipment necessary for the proper construction of this work shall be on the project, in first-class working condition, and shall have been approved by the engineer before construction is permitted to start. Provision shall be made by the contractor for furnishing water at the site of the work by equipment of ample capacity and of such design as to assure uniform application. The processing equipment shall be designed, constructed, operated, and of such capacity so as to thoroughly mix all materials and water in the proportions as directed to produce a subbase course of the gradation and consistency required. 154-3.4 PREPARING UNDERLYING COURSE. Before any subbase material is placed, the underlying course shall be prepared and conditioned as specified. The course shall be checked and accepted by the engineer before placing and spreading operations are started. Grade control between the edges of the runways shall be by means of grade stakes, steel pins, or forms placed in lanes parallel to the centerline of the runway and at intervals sufficiently close that string lines or check boards may be placed between the stakes, pins, or forms. To protect the subgrade and to insure proper drainage, the spreading of the subbase shall begin along the centerline of the runway or taxiway on a crowned section or on the high side of the pavement with a one-way slope. 154-3.5 MATERIALS ACCEPTABLE IN EXISTING CONDITION. When the entire subbase material is secured in a uniform and satisfactory condition and contains approximately the required moisture, such approved material may be handled directly to the spreading equipment for placing. The material may be obtained from gravel pits, stock piles, or be produced from a crushing and screening plant with the proper blending. The materials from these sources shall meet the requirements for gradation, quality, and consistency. It is the intent of this section of the specifications of securing materials that will not require further mixing. The moisture content of the material shall be approximately the required moisture content to obtain maximum density. Any minor deficiency or excess of moisture may be corrected by surface sprinkling or by aeration. In such instances some mixing or manipulation may be required immediately preceding the rolling to obtain the required moisture content. The final operation shall be blading or dragging, if necessary, to obtain a smooth uniform surface true to line and grade. 154-3.6 PLANT MIXING. When materials from several sources are to be blended and mixed or when required in the proposal, the subbase material shall be processed in a central mixing plant or in |