A. 
Pipe size, type, joint and class shall be designated on the plans or specified elsewhere. Unless otherwise approved in writing by the District, or as specifically indicated on the plans approved by the District, all pipe, fittings, and accessories shall be as delineated in this section.
B. 
All pipe used for force mains shall be of the pressure type with pressure-type joints.
All pipe shall be one of the following:
A. 
Ductile iron pipe.
(1) 
Ductile iron pipe shall be centrifugally cast metal molds or sand lined molds with a thickness approved for gravity sewers. Class 50 cement lined conforming to AWWA C104. Ductile iron pipe for force mains shall be cement-mortar lined in accordance with AWWA C104 Specification. Cement for the mortar shall be Type II Portland cement.
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
(2) 
Mechanical joints and push-on joints shall be manufactured in accordance with AWWA C111. Gaskets shall be furnished by the pipe manufacturer. Ductile iron pipe with flanged joints shall be manufactured in accordance with ANSI Specification A21.15.
(3) 
Fittings shall be manufactured in accordance with ANSI Specification A21.10. All fittings shall be cement-mortar lined inside in accordance with ANSI Specification A21.4. The coatings of the fittings shall be as specified for the pipe.
B. 
Polyvinyl chloride pipe. Pipe for gravity sewers shall be manufactured in accordance with ASTM Designation D3034 and shall meet the requirements for SDR 35. Joints shall consist of an integral wall section with a solid cross section rubber gasket conforming to ASTM Designation D-1869. Minimum "pipe stiffness" (F/Y) at 5% deflection shall be 46 psi when tested in accordance with ASTM D-2412. The maximum allowable deflection shall be 5% after backfill has reached 95% compaction. PVC pipe for force mains shall be in accordance with AWWA C900.
C. 
Air release valve assemblies.
(1) 
Air release valve assemblies shall be installed at high points in the line or where required otherwise. Each assembly shall consist of an approved one inch corporation stop, a riser pipe a of suitable length, and a one inch air release valve equal to Crispin Model US205B. A one-inch ball valve shall be installed as shown in the construction standards to allow servicing of the air release valve.
(2) 
The air release valve assembly enclosure or chamber shall have a cast iron frame and cover of sufficient size equal to Ford Meter Box Company, Incorporated.
A. 
General. All manholes on one project shall be constructed of the same materials; all cleanouts on one project shall be constructed of the same materials.
B. 
Concrete. Structural concrete shall be used for the construction of foundation slabs and special structures. All concrete shall be in accordance with § 332-37, Concrete.
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
C. 
Waterproofing. The waterproofing material shall be Bitumastic No. 50 or approved equal.
D. 
Frames, covers and steps.
(1) 
Frames and covers shall be the best quality gray iron, cast in accordance with ASTM Designation A-46 or ASTM A536 for ductile iron. Castings shall be sound, true to form and thickness, sand blasted clean and machined on all bearing surfaces. Steps shall be polypropylene coated smooth steel rod.
(2) 
Watertight manhole covers are to be used whenever the tops may be subject to flooding. As a minimum watertight covers are to be used to the elevation of the fifty-year flood/wave action.
E. 
Precast concrete manholes.
(1) 
Precast concrete manholes shall be constructed of reinforced concrete. Rubber gaskets shall be the round "O" ring type conforming to ASTM Designation C-443 or ASTM C990 for bitumen or butyl rubber.
(2) 
Flexible connections for pipe jointing at the manhole shall be comprised of rubberboots and stainless steel straps or approved equal. The waterproofing material shall be Bitumastic No. 50 or approved equal.
A. 
General requirements. All work shall comply with the "Building Code Requirements for Reinforced Concrete," ACI 318, latest edition.
B. 
Materials:
(1) 
Concrete. Unless otherwise indicated on the drawings, concrete for structures shall be proportioned and mixed in accordance with the Road and Bridge Specifications, Virginia Department of Transportation, dated 2002, General Use Concrete, Class A-3, Table II-17, Section 217. Concrete for miscellaneous purposes, such as fill concrete, thrust blocks, concrete encasement, etc., shall have a twenty-eight-day strength of 2,500 psi. The mix proportions and test data for this concrete shall be submitted by the contractor for approval by the District. All concrete shall be made with Type II Portland cement manufactured in accordance with ASTM C-150.
(2) 
Steel reinforcement. All reinforcement bar shall be deformed new billet steel conforming to ASTM A615-40 Grade 60. Bars shall be formed to the dimensions indicated by the drawings.
(3) 
Wire reinforcement. Welded wire fabric shall conform to ASTM Designation A185.
(4) 
Curing compound. Curing compound shall conform to ASTM Designation C309, Type 2.
(5) 
Joint filler. Expansion joint material shall conform to AASHTO M213.
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
(6) 
Joint sealant. All concrete joints shall be prepared and sealed with Colma joint sealer, as manufactured by Sika Chemical Corporation, W.R. Grace Joint Sealer, or equal.
(7) 
Waterstops. Flexible waterstops shall be manufactured from virgin polyvinyl chloride plastic compound. Properties of polyvinyl chloride used shall conform to Corps of Engineers Specification CRD-C572. All waterstops shall be capable of withstanding a head of water equal to the depth of installation or 30 feet, whichever is greater.
C. 
Slump. Slump shall be from two to four inches and will be determined in accordance with ASTM Method C143. Samples for slump determination will be taken from the concrete during placement in the forms.
D. 
Testing. The twenty-eight-day concrete compressive strengths will be verified during the progress of the work by testing standard concrete cylinders. The owner shall furnish the necessary labor, molds, and facilities for taking the samples and handling and storing the cylinder at the site of the work. The making, curing, and testing of specimens will be in accordance with ASTM Method C31 and C39. For the first 24 hours after molding, the cylinders shall be kept moist in a storage box constructed and located so that its interior air temperature will be between 60° and 80° F. At least three cylinders will be required for each 50 cubic yards of concrete placed or for each item of work. Should the cylinder specimens fail to meet the specified strength, sample cores may be cut from the suspect concrete at the District's direction. Concrete shall be deemed acceptable if these cores test at 85% design strength. If not, a load test shall be performed as outlined by ACI 318. All core testing shall be performed at the owner's expense. If still unsatisfactory, any necessary support and remedial work shall be furnished by the owner's contractor.
E. 
Forms.
(1) 
All concrete shall be formed unless directed otherwise. Forms shall be true to line and grade and shall be mortar tight. All exposed joints, edges, and external corners shall have 3/4 inch chamber. Forms shall be of wood, plywood, or steel. Form design shall be subject to approval, but the adequacy of ties, supports, bracing and shoring to support the imposed live and dead loads, etc., shall remain the responsibility of the developer. Embedded wall ties shall be set 1 1/2 inches from exposed concrete surfaces. The heights or form for each vertical lift shall not exceed 10 feet unless indicated on the drawings. Forms for continuous surfaces shall be fitted over the completed surface to assure alignment and to prevent leakage of mortar. Before placing reinforcement steel the contact surfaces of forms shall be cleaned and coated with a nonstaining form oil. Temporary openings shall be provided at the base of column and wall forms to facilitate cleaning just prior to concrete placement.
(2) 
Embedded items such as anchor bolts, frame curb angle, conduit, pipe sleeves, and openings shall be carefully located and securely anchored in the forms.
(3) 
Forms for columns, walls, sides of beams, and other members not supporting the weight of the concrete may be removed 36 hours after placing of concrete. Supporting forms for beams, girders, and slabs shall remain in place until the concrete has reached its twenty-eight-day strength.
F. 
Construction joints. Construction joint surfaces shall be thoroughly cleaned before placement of concrete. All laitance, coatings, stains, debris, and other foreign material shall be removed from the surface before the new concrete is deposited. Waterstops and shear keys shall be provided at construction joints. Joints in metal waterstops shall be vulcanized. Waterstops shall be installed so as to form a continuous watertight seal in each joint. Construction joints will not be permitted within two feet of design water level on wetted surfaces. Shear keys shall be installed for ease of removal of the form. Blockouts for pipe sleeves, if approved by the District, shall be provided with keyway and waterstops and shall be detailed as a plug.
G. 
Placing reinforcement. Steel reinforcement bars shall be placed in accordance with the approved detail drawings and shall be supported by concrete blocks or galvanized metal bar chairs. Reinforcement shall be free from loose rust, mill bond. Reinforcement shall be held securely in place to prevent dislocation during concrete placement.
H. 
Delivery of concrete.
(1) 
Concrete mixing equipment and methods shall be subject to approval. Each load shall be accompanied by a ticket showing mix design, mix starting time, and batch weights. The maximum time between introduction of cement into the concrete readymix truck and discharge into the forms shall be two hours where the temperature is less than 80° F. and 1 1/2 hours above 80° F. Any deviation from the mixing time and the truck ticket information required shall be cause for return of the concrete without use in the forms.
(2) 
Concrete manufactured at the job site shall be subject to the requirements of the aforesaid Road and Bridge Specifications.
I. 
Placement of concrete. Concrete placing equipment and methods shall be subject to approval. All surfaces, forms, etc., shall be thoroughly cleaned of debris, dirt, wood chips, etc., and shall be thoroughly dampened prior to placement. Concrete shall not be placed under water. Cement-sand grout in mix proportions of one to three by weight shall be placed to a depth of one inch at all contact surfaces between old and new concrete. The maximum free fall of concrete during placement shall be six feet. Placement at greater heights than six feet shall be accomplished by chutes, slides, or other approved methods. Concrete shall be placed so as to avoid formation of cold joints between successively deposited layers. Concrete shall be placed in the dry and placement will not be permitted during adverse weather conditions. To prevent segregation, the concrete should be deposited in approximately horizontal layers of 12 inches to 18 inches as near as possible to its final position.
J. 
Vibration. All concrete shall be consolidated with high frequency, internal, mechanical vibrating equipment supplemented by hand spading and tamping. Vibrators shall be designed to operate with the vibratory element submerged in the concrete and shall have a frequency of not less than 7,000 impulses per minute when submerged. Adequate numbers of sufficiently powered vibratory units shall be furnished at all times to properly consolidate the concrete. Vibration of forms and reinforcement shall not be permitted. Vibrators shall not be used to transport the concrete in the forms. Where concrete is placed in more than one lift, the vibrator shall penetrate the previous lift to prevent the formation of cold joints.
K. 
Placing concrete in cold weather. Except on specified authorization, concrete shall not be placed when the atmospheric temperature is below 40° F. Requests for permission to place concrete at less than 40° F. shall include the method to be used to provide concrete at 55° F. and to maintain a temperature of 60° F. during the seven-day curing period. Placing and curing of concrete during cold weather shall conform to ACI 306. Materials for heating concrete shall be on site and in proper working order prior to placing concrete.
L. 
Repair of surface defects.
(1) 
Surface defects shall be repaired immediately after form removal. Honeycombed and other defective concrete shall be removed down to sound concrete. A 1:1 sand-cement bonding grout shall be brushed into the surface; then a stiff patching mixture of the same proportions as the concrete, except coarse aggregate, shall be applied to the defective area. The patching mixture shall be thoroughly consolidated and struck off slightly higher to allow for shrinkage, then finally finished one hour later. The patch shall be kept damp for seven days.
(2) 
Tie holes shall be cleaned, thoroughly dampened and filled solid with patching mortar.
M. 
Surface finish.
(1) 
Concrete surfaces not treated architecturally shall be finished as follows. Exposed wall shall be rubbed immediately after form removal and completion of all patching. Surfaces shall be wetted and rubbed with carborundum brick or other abrasive until a uniform color and texture are produced. No additional cement grout shall be used other than that paste drawn from the green concrete by the rubbing process.
(2) 
Floor slabs shall receive a steel trowel finish. The surface shall be initially float finished after the mix has hardened sufficiently to permit proper operation of a power-driven float. Power troweling and hand troweling shall complete the slab finished which shall be free of trowel marks, uniform in texture and appearance and shall be true within 1/4 inch in 10 feet, determined by a ten-foot straight-edge placed anywhere on the slab. All concrete floors, unless noted otherwise, shall be treated with a floor hardener of Masterplate, as manufactured by Master Products Company, or Hydroment, as manufactured by USM Corporation, or approved equal.
(3) 
Stair treads and other surfaces requiring a nonslip finish shall be finished with a wood float. Aluminum oxide abrasive aggregate particles shall be spread on the surface at a rate of 1.25 pounds per square foot and floated to a uniform granular finish.
N. 
Protection and curing. Concrete shall be protected adequately from injurious action by the sun, rain, flowing water, frost and mechanical injury, and shall not be allowed to dry out for seven days after placing. Curing shall be accomplished by water curing or by application of curing compound, except that compound shall not be used on surfaces to be rubbed, or where its appearance would be objectionable or where additional concrete is to be placed. Vertical wall forms shall be kept continuously wet while the forms are in place.