Construction Requirements 620.03 A foundation bed shall be excavated in accordance with Section 206, or as directed by the Engineer. Stones shall be laid flat on firm beds and securely placed, with broken joint lines. The larger stones shall generally be located in the lower part of the structure and voids shall be eliminated to the extent possible. Spalls smaller than the minimum stone-size specified in subsection 620.02 shall be used to chock the larger stones solidly in position and to substantially fill voids between the major stones as laid in the embankment. The exposed face of the rock mass shall be reasonably uniform, with no projections of more than 12 inches (305 mm) for derrick-placed embankment or 6 inches (152 mm) for hand-laid embankment, beyond the neat line shown on the plans or directed by the Engineer. Backfill adjacent to the rock embankment shall consist of material from excavation items, compacted in accordance with Section 203. Method of Measurement 620.04 The quantities to be paid for will be the number of cubic yards, measured in place, or tons, of special rock embankment of the kind shown by the bid schedule, furnished, placed, and accepted. Basis of Payment 620.05 The quantities determined as provided above, will be paid for at the contract price per unit of measurement for each of the pay items listed below that appear in the bid schedule, which price and payment will be full compensation for the work of this section, except that excavation will be paid for as provided in Section 206 and backfill material will be paid for under the appropriate section. Payment will be made under: Pay item 620(1) Hand-laid rock embankment. Pay unit Cubic yard. Ton. Section 621.-CORRUGATED METAL SPILLWAYS Description 621.01 This work shall consist of furnishing and installing corrugated metal spillway inlet assemblies and outlet pipes, and other appurtenances in accordance with these specifications, and in reasonably close conformity with the design, grades and at the locations shown on the plans or as established by the Engineer. Materials 621.02 Spillway inlet assemblies, outlets and connectors, shall be of the type and thicknesses shown on the plans, and shall be constructed of corrugated sheet metal conforming to the requirements of Section 603. The dimensions and proportions of inlet assemblies shall be in substantial agreement with those of the design shown on the plans, but minor variations may be accepted at the discretion of the Engineer to permit the use of manufacturer's standard jigs and templates in the fabrication. Bulkheads and connections for outlet pipes shall be filletwelded or riveted to the inlet chamber to form watertight joints. Anchors, lips, and skirts shall be securely riveted or welded. Connections for outlet pipes shall be of the size shown on the plans and shall conform to the requirements of Section 603 except that all coupling bands shall be not less than 12 inches (305 mm) wide. Outlet pipes shall be full circle, half-round, or a combination of both, of the size and arrangement shown on the plans, and shall meet the applicable requirements for corrugated metal pipe in Section 603. Half-round pipe shall have end sections punched to permit riveting of joints in the field. Elbows shall be of the full-circle type. Other components shall be as shown on the plans. When called for in the bid schedule, spillway inlet assemblies and outlet pipes shall be bituminous coated as required for bituminouscoated corrugated pipe in Section 603. Construction Requirements 621.03 Spillway inlets shall be placed in the position shown on the plans and the earth backfill shall be consolidated by tamping. Outlet pipes shall be installed in accordance with the requirements in Section 603. All field joints for half-round pipe shall be riveted. Care shall be used to prevent damage to the asphalt coating during hauling and placing. All spots on the inlet assemblies or pipe where the coating has been damaged and all field rivet heads shall be painted with two coats of an approved asphalt paint. Method of Measurement 621.04 The quantity of spillway inlet assemblies to be paid for will be the number installed and accepted. The quantity of half-round outlet pipe to be paid for will be the actual number of linear feet of pipe of the several sizes, measured as installed in place, completed, and accepted. The measurement will be from end to end of each outlet pipe, excluding elbows. Full-circle outlet pipe will be measured as provided in Section 603. Basis of Payment 621.05 The quantities, determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each of the particular pay items listed below that is shown in the bid schedule, which prices and payment will be full compensation for the work prescribed in this section, except full-circle outlet pipes and fittings which will be paid for as provided in Section 603. Payment will be made under: 622.01 This work shall consist of paving ditches, gutters, spillways, and other similar waterways with concrete, grouted rubble, mortared rubble, concrete and rubble, or a mixture of aggregate and bituminous material, constructed on a prepared bed in reasonably close conformity with these specifications and with the lines, grades, and dimensions shown on the plans or established by the Engineer. If shown on the plans, the work shall include the construction of a bed course. Materials 622.02 Materials shall meet the requirements specified in the following sections or subsections: 703 Aggregates for bituminous mixture___ Materials and proportions for bituminous mixtures will be specified in the special provisions. Rubble for pavement shall consist of approved, sound, durable stone of the sizes indicated on the plans. All stone will be inspected before and after laying, and all rejected material shall be removed immediately from the work. Construction Requirements 622.03 Bed. The bed shall be formed at the required depth below and parallel with the finished surface of the waterway. All soft and yielding or other unsuitable material shall be removed and suitable material substituted. The bed shall be compacted and finished to a smooth, firm surface. If shown on the plans, bed course material shall be placed and compacted to form a bed course of the required thickness. 622.04 Grouted Rubble. The pavement stones shall be bedded in the foundation with flat faces up and their longest dimensions at right angles to the center line of the waterway. Joints shall be broken and shall not exceed 1 inch (25.4 mm) in width. The stones shall be rammed until the surface is firm and reasonably true to the finished surface in grade, alinement, and cross section. Any stone having an irregular or uneven surface shall be taken up and satisfactorily relaid. After the stones have been rammed into place and the surface is satisfactory, the spaces or voids between and around the stones shall be filled with filler aggregate to within 4 inches (102 mm) of the surface, after which cement grout shall be poured and broomed into the spaces between the stones, this operation being continued until the grout remains about 1 inch (25.4 mm) below the tops of the stones. The grout shall be of such consistency that it will flow readily into the spaces between the stones, but it shall not be so wet that the solid matter separates from the water. 622.05 Mortared Rubble. The pavement stones shall be laid with flat faces up and their longest dimension paralled to the gutter line. Joints shall be broken and shall not exceed 1 inch (25.4 mm) in width. After each stone has been rammed into place and the surface is satisfactory, mortar shall be applied on its exposed side in such quantities that when the adjacent stone is placed and rammed into position the mortar shall fill, to within an inch (25.4 mm) of the surface, the interstices between the rock, but shall not protrude above their tops. The finished rock surface shall be free from mortar stain. 622.06 Reinforced Concrete and Rubble. Upon the prepared foundation constructed to the lines and grades established by the Engineer, a reinforced concrete foundation shall be as shown on the plans. This foundation shall be constructed progressively with the laying of surface stones in such a manner that stones shall be securely bedded in the concrete before it hardens. The face of stone in contact with the concrete shall be clean and free from any defects that will impair its bond with the concrete. Prior to laying, stones shall be thoroughly wetted, with allowance of ample time for absorption to near saturation. Joints between stones shall be filled with mortar. Adequate means shall be provided for keeping the reinforcement steel bedded within the middle third of the depth of the concrete as construction proceeds. 622.07 Bituminous Mixture: (a) Preparing mixture.-The mixing may be done in either a rotary or pugmill type mixer or by spreading the aggregate on a flat, firm surface, off the area to be surfaced, applying the bituminous material and mixing by road-mix methods. If a pugmill is used, it may be either the batch or continuous type. Except when emulsified asphalt is used, the aggregate shall not contain more than 2 percent of moisture at the time it is mixed with the bituminous materials. However, if the Contractor elects to use an additive approved by the Engineer, the aggregate may contain moisture up to a maximum of 5 percent. Bituminous material shall be applied to the aggregate or introduced into the mixture at the temperature at which the aggregate will be coated uniformly and completely. When mixing is done in a mixer, the mixing period, measured from the time all materials are in the mixer until they are discharged, shall not be less than 40 seconds. When road-mix methods are used, the mixing shall continue until all aggregate particles are uniformly coated with bituminous material. |