702-4.2 The volume of concrete for pipe cradles to be paid for shall be the number of cubic yards of concrete complete in place and accepted, determined from the dimensions shown on the plans, or as ordered by the engineer. 702-4.3 Rock required to be removed shall be computed by the cubic yard for the specified width of the trench and to a depth of four (4) inches below the bed of the pipe. No payment will be made for the cushion material placed for the bed of the pipe. BASIS OF PAYMENT 702-5.1 The footage of pipe, measured as provided in Section 4.1, shall be paid for at the contract unit price per linear foot for "Concrete Pipe" of the several classes, types, and sizes, which price and payment shall constitute full compensation for furnishing, hauling, and installing the pipe; for common excavation; for backfill and compaction; for jointing; for connections to drainage structures; and for all material, labor, equipment, tools, and incidentals necessary to complete the drain as shown on the plans, but shall not constitute payment for manholes, catch basins, inlets, cradles, inspection holes, or headwalls, the payment for which is provided for as separate items. 702-5.2 The cubic yards of concrete determined as provided in Section 4.2 shall be paid for at the contract unit price per cubic yard for "Concrete for Pipe Cradles," which price and payment shall constitute full compensation for concrete in place including reinforcing when shown on the plans. 702-5.3 The cubic yards of rock excavation, determined as provided in Section 4.3, shall be paid for at the contract unit price per cubic yard for "Rock Excavation," which price and payment shall constitute full compensation for excavation, placing cushion material, and disposal of material as defined. Item D-702-5.1 ----inch Standard Reinforced Concrete Sewer Item D-702-5.1 ----inch Standard Strength Reinforced Con- Item D-702-5.1 inch Extra Strength Reinforced Concrete Item D-702-5.2 Concrete for Pipe Cradles-per cubic yard. Item D-702-5.3 Rock Excavation-per cubic yard. ITEM D-703 CORRUGATED METAL PIPE, GALVANIZED, OR GALVANIZED AND BITUMINOUS-COATED, FOR STORM SEWERS AND CULVERTS DESCRIPTION 703-1.1 This item shall consist of corrugated sheet metal pipe of the types, classes, sizes, gauges, and dimensions required on the plans, furnished and installed at such places as are designated on the plans and profiles, or by the engineer, in accordance with these specifications and in conformity with the lines and grades given. The item shall include, in the bid price per linear foot of pipe in place, the cost of common excavation and backfill, the cost of furnishing and installing all trench bracing, all fittings required to complete the pipe drain, as shown on the plans; and the material for and the making of all joints, including all connections to existing drainage pipes and structures. MATERIALS 703-2.1 GENERAL. The pipe shall be of the type called for on the plans or in the proposal and shall be in accordance with the following appropriate requirements. When the plans or the proposals permit a choice of pipe, the contractor shall indicate in the bid the type proposed to be furnished. 703-2.2 CORRUGATED METAL CULVERT PIPE. Corrugated metal culvert pipe shall conform to the requirements of A. A. S. H. O. Specification M-36. 703-2.3 BITUMINOUS-COATED CORRUGATED METAL CULVERT PIPE. The pipe shall conform to all the requriments of A. A. S. H. O. Specification M-36, and in addition shall be coated with an asphalt cement that will meet the following requirements: (a) Type 1-Coated Pipe. The pipe shall be coated uniformly, inside and out, to a minimum thickness of 0.05 of an inch, measured on the crests of the corrugations. (b) Type 2-Coated and Paved Pipe. The pipe shall be coated as required for Type 1 pipe. In addition, bituminous material shall be applied in such a manner that a smooth pavement will be formed in the invert (bottom of pipe when installed) and the corrugations will be filled for one-quarter of the circumference of the pipe. The pavement, except where the upper edges intersect the corrugations, shall have a minimum thickness of 0.37 inch, measured on the crests of the corrugations.e (c) Bituminous Material. The tests on the bituminous coating shall be made on samples secured from pipe delivered to, or about to be delivered to, the project. The asphalt cement shall be not less than 99.5 percent soluble in carbon disulphide (A. A. S. H. O. Method T-44). The loss on heating the material to 325° F. shall not exceed one (1) percent (A. A. S. H. O. Method T-47). The penetration of the residue from loss on heating, compared with the penetration of same sample before heating, shall be not less than eighty-five (85) percent (A. A. S. H. O. Method T-49). The asphalt cement shall adhere to the metal tenaciously, shall not chip off in handling, and shall protect the pipe from deterioration, as evidence by meeting the following tests successfully: (1) STABILITY TEST. The asphalt cement shall not lose its stability when subjected to the highest summer temperature, as indicated by passing the test performed as follows: Parallel lines shall be drawn along the valleys of the corrugations of a representative sample of coated pipe and the specimen placed on end in a constant temperature oven, with the parallel lines in a horizontal position. The temperature of the specimen shall be maintained within 2° F. of 150° F., for a period of 4 hours. At the end of this time no part of any line shall have dropped more than one-fourth (4) inch. (2) IMPERVIOUSNESS TEST. The asphalt cement shall be impervious to liquids as indicated by passing the test performed as follows: A 25-percent solution of sulphuric acid, or a 25-percent solution of sodium hydroxide, or a saturated salt solution (such as sodium chloride) shall be held in the valley of a corrugation for a period of 48 hours, during which time no loosening or separation of the bituminous material from the galvanizing shall have taken place. 703-2.4 MORTAR. Mortar for connections to drainage structures shall be composed of one part by volume of Portland cement and two parts of mortar sand. The Portland cement shall conform to the requirements of A. S. T. M. Designation C-150, Type 1. The sand shall conform to the requirements of A. A. S. H. O. Specification M-45. Hydrated lime may be added to the mixture of sand and cement in an amount equal to fifteen (15) percent of the weight of cement used. 703-3.1 CONSTRUCTION METHODS EQUIPMENT. All equipment necessary and required for the proper construction of storm sewers and culverts shall be on the project, in first class working condition, and shall have been approved by the engineer before construction is permitted to start. The contractor shall provide such hand tampers and pneumatic tampers to obtain the compaction of the pipe bed and the backfill as specified. 703-3.2 EXCAVATION. (a) Common. The contractor shall do all common excavation to the depth shown on the plans. Common excavation shall consist of all excavation not included under rock excavation. (b) Rock. The contractor shall do all rock excavation to the depth shown on plans plus at least four (4) inches. Rock excavation shall consist of the removal of boulders and detached rock, one-half (2) cubic yard in volume or greater, and of all rock in place in ledges or masses which can be removed only by the use of bars and sledges or by blasting. When rock or noncushioning material is encountered in trench excavation, a cushion at least four (4) inches thick shall be placed between the rock and the bottom of the pipe. The cushion shall consist of clean sand or equivalent granular material. The cost of furnishing and placing the cushion material shall be included in the bid price per cubic yard for rock excavation. Before any rock is removed, the engineer shall have the opportunity to obtain the necessary data to determine the yardage to be used for payment. The bottom of the trench shall be excavated to a horizontal section as far as practicable. (c) General. Excavated material not required or acceptable for backfilll shall be disposed of by the contractor as directed by the engineer. Common excavation shall not be carried below the required depth; when this is done the trench shall be backfilled at the contractor's expense with material approved by the engineer and compacted to the density of the surrounding earth material as determined by the CAA compaction control tests T-611. When directed, unstable soil shall be removed for the full width of the trench and replaced with sand or with approved granular material. The engineer shall determine the depth of removal of unstable soil and the amount of backfill necessary. The backfill shall be thoroughly compacted and shaped to form the bed for the pipe. When not specified in the special provisions, the cost of removing unstable soil and replacing it with approved material shall be covered by a supplemental agreement for the cubic yards of excavation and the cubic yards of approved material. The depth of cut shown on the plans is from the surface grade to the invert of the pipe line. In case the depth of cut is changed from that shown on the plans, the change shall not exceed six (6) inches without a revision in the contract unit price per linear foot of pipe. However, if the depth of cut is changed more than six (6) inches, compensation or deduction of work involved, whether increased or decreased, shall be provided for in a supplemental agreement. The minimum width of the trench at the top of the pipe, when placed, shall be a width which will permit the proper construction of joints and compaction of backfill around the pipe, but shall be at least equal to the outside diameter of the pipe plus six (6) inches on each side of the pipe. The trench shall be excavated accurately to the established line so that at least a six (6) inch space will exist between the side of the trench and the side of the pipe. The sides of the trenches shall be vertical, unles otherwise approved by the engineer. The maximum allowable width of trench shall not exceed twelve (12) inches on each side of the pipe when placed, unless otherwise approved by the engineer. The bed for the pipe shall be so shaped that at least the lower quarter of the pipe shall be in continuous contact with the bottom of the trench. The contractor shall do such trench bracing, sheathing, or shoring necessary to perform and protect the excavation; also, as required for safety and to conform to governing laws. Unless otherwise provided the bracing, sheathing, or shoring shall be removed by the contractor after the completion of the backfill to at least six (6) inches over the top of the pipe. The cost of the bracing, sheathing, or shoring, and the removal of same, shall be included in the unit price bid per foot for the pipe. 703-3.3 PLACING PIPE. The pipe shall be laid with the separate sections joined firmly together, with coupling bands described in A. A. S. H. O. Specification M-36, with outside laps of circumferential joints pointing upgrade, and with longitudinal laps on the sides. Any metal in the pipe or bands which is not protected thoroughly by galvanizing shall be coated with a suitable asphaltum paint. Proper facilities shall be provided for lowering the pipe when it is to be placed in a trench. The pipe shall be laid carefully and true to lines and grades on a bed which is uniformily firm throughout its entire length. Any pipe which is not in true alignment, or which shows any undue settlement after being laid or is damaged, shall be taken up and relaid or replaced without extra compensation. During installation, the asphalt-protected pipe shall be handled without damaging the asphalt coating. The pipe shall be placed so that the element of the cylindrical pipe constituting the centerline of the paved section shall coincide with the flow line of the culvert or sewer. Sections of paved pipe shall be laid so that the flow line is smooth and continuous across joints. Any breaks in the bitumen or treatment of Type 1 or Type 2 pipe shall be repaired with the type and kind of bitumen used in coating the pipe originally. Pipes 48 inches or larger in diameter shall be strutted as shown on the plans. The struts shall be placed before the backfill or embankment is made, and shall be removed when removal is ordered by the engineer. Pipe shall not be laid on frozen ground. 703-3.4 MORTAR. Mortar shall be mixed in a ratio of one part by volume of Portland cement and two parts by volume of sand. The mortar shall be of the desired consistency for caulking and filling between the pipe and the drainage structures. Mortar that is not used within forty-five (45) minutes after water has been added shall be discarded. Retempering of mortar will not be permitted. 703-3.5 BACKFILLING. All trenches and excavations shall be backfilled in a reasonable time after the pipes are installed therein unless other protection of the pipe is directed by the engineer. The |