AASHTO Specs for Storm Water Drainage Pipes, Manholes ETC.

DIGGINGS:

Traffic diversions and signs:

• Before embarking on excavations or backfilling of any work, the contractor must obtain the necessary permits from the relevant authority and provides the engineer with copies of these permits.
• The contractor shall be responsible for preparing traffic diversion plans along the parts of the project before starting work, then establishing and maintaining them during the period of work and removing them after the completion of the works and returning the surface to its origin.
• The roads and streets of the project, including diversions and entrances, must be kept in a safe position, and the contractor must provide appropriate entrances to the site and ensure that traffic is not obstructed as a result of these entrances.
• Equipping all diversions with various barriers so that they are adjacent without voids and with regulatory and warning road signals in accordance with what is stated in the bills of quantities, engineering plans and schedules, and?the contractor must provide any pedestrian bridges or crossings for traffic,?provided that they are of sufficient durability over the trench whenever necessary.?
• Traffic lights must be provided, if necessary.

Earthen and rock fossils:

• The contractor must remove all materials on the surface and determine and plan the proper course before commencing excavation. The width of the pipe trench shall not exceed the maximum permissible limit and shall not be less than the minimum dimensions shown in the plans. The sides of the trench shall be vertical, and the contractor shall take adequate measures to obtain the approval of the engineer to protect the sides of the excavated trench from collapse by using a method approved by the supervising engineer to support the sides of the excavation and the bottom of the excavations shall be according to the required inclination according to the plans. And if there is ground water or water from the wells, or leaks from the water pipes. the contractor shall pump this water, drain the trench and submit a proposal for soil treatment in these areas approved by the engineer or his representative.
• Soil excavations mean drilling in soft materials or incoherent hard materials and stones, which can be dug with ordinary soil excavators, while hard rocks that can only be dug by a rock crushing machine (Jack Hammer) are considered rock fossils.
• The contractor should record the level of the rock surface and detect it at a distance of every 10 meters at the same stations from which the soil levels were taken with the engineer's representative and present it to the supervising engineer in a profile plan (cross sector) for approval and then to calculate the actual quantities in the item.

Trench width:

The width of the trenches of the various box pipes and channels will be restricted to the following maximum and minimum sizes:

• Pipes with a diameter of 300 mm – 600 mm:

1. The minimum width of the trench = outer diameter + 40 cm.
2. Maximum trench width = outer diameter + 80 cm.

• Pipes with a diameter of 700 mm – 1000 mm:

1. The minimum width of the trench = outer diameter + 50 cm.
2. Maximum trench width = outer diameter + 90 cm.

• Pipes with a diameter greater than 1000 mm:

1. The minimum width of the trench = outer diameter + 60 cm.
2. Maximum trench width = outer diameter + 100 cm.

• For box channels made of reinforced concrete:

1. Minimum width of the trench = external width of the channel + 100 cm.

Excess excavations:

• If there are excavations in excess of the maximum width shown in the plans, the contractor shall fill the excess part of the excavation with Class C concrete as requested by the engineer. If the excavations are excessive in depth, they can be stuffed with the same mattress material provided that the increase in digging does not exceed 20 cm. If it is more than that, Class C concrete shall be used, and the backfilling of excess excavation fillings shall be at the expense of the contractor.

Removal of excavated materials:

• All excavated materials must be removed from the site by trucks equipped with a suitable cover that prevents dust and stones from flying. The contractor shall propose sites for the disposal of excavated materials and obtain prior permission from the competent authority.

MATERIALS:

Reinforced Concrete Pipe:

• Comply with ASTM C76M, Class IV, with Wall Type [A] [B] [C]. Concrete for pipes and fittings shall be to the requirements of Division 3 of the specification and shall be made using ordinary Portland cement.
• The entire interior surfaces of pipes and fittings shall be lined with a GRP lining to the product requirements. GRP lining should cover the entire interior of the pipe.
• The GRP lining should be casted into the pipe at the time of manufacture of the concrete pipes. Line the pipes entirely unless otherwise noted.
• The GRP lining cast sheets should be as large as practicable to adequately fit the intended use:

1. Form large sheets by lapping basic size sheets a minimum of 13mm and fusing the sheets together in such manner as to produce a continuous welded joint. Do not allow tears, cracks, or separation in the laps.
2. Cast joint strips of 100mm, ±1 mm in width x 2mm minimum thickness and bevel each edge prior to application.
3. Cast welding strips of 25mm, ±2mm in width x 3mm minimum to 4mm maximum thickness. Use bevelled edges for all welding and outside corner strips at time of manufacture.
4. Maintain all lining sheets, including locking extensions or studs, all joints corner, and welding strips free of cracks, cleavages, or defects adversely affecting the protective characteristics of the material. The Engineer may authorise the repair of such defects by approved methods.
5. Apply and secure lining to the forms. Inspect and approve the lining application prior to the placement of reinforcing steel.

• The entire exterior surface should be coated with an approved solvent free 2 component epoxy system. All blowholes and surface defects must be filled with a two-component solvent free epoxy filler prior to top coating.
• Reinforcement: Mesh.
• Inside Nominal Diameter: in mm as per drawings.
• End Connections: Bell and spigot.
• Fittings: Reinforced concrete.
• Joints:

1. Rubber compression gasket.
2. Comply with ASTM C443M and ASTM C361 or BS EN 681.

Double Wall HDPE with smooth interior and corrugated exterior (Type S):

• AASHTO M294, ASTM D2122 Type S, bell and spigot joints tested at pressure at least 11 psi in conformance with ASTM D3212, pipe stiffness in accordance with ASTM D2412

PVC Sewer Pipe and Fittings:

• AWWA C900, Class 100, or DIN 8062, Class 6 kg/cm2; for gasketed joints.

1. Gaskets: ASTM F 477, or BS EN 681: Parts 1 and 2, BS EN 682 and BS 7874, elastomeric seals.

GRP Sewer Pipes and Fittings:

• Pipes and fittings to ASTM D3754, ASTM D3262, ASTM D3517, AWWA M45 and AWWA C950.
• The liner shall have a nominal thickness of 1.0 mm. The liner surface shall be reinforced with "C" glass. The remainder of the liner thickness shall be reinforced with an acid resistant chopper "E" glass strand or mat.
• Pipes shall be provided with a resin rich outer layer reinforced with one layer of "C" glass veil. The exterior layer shall have a minimum thickness of 0.2 mm. The resin layer shall be rich and reinforced with one layer of C glass.
• The resin used for the corrosion resistant liner of the pipe and fittings shall be high grade polyester resin (isophthalic or better) type. For the structural wall and exterior layer of the pipe a high grade isophthalic polyester resin shall be used. No dark pigments shall be used in the pipe or fittings.
• Pipes shall be designed for a life of not less than 50 years. Contractor shall submit calculations for initial and long-term deflection with Truck loads, Buckling, Vacuum, Pressure Class, and Strain in accordance with Appendix "A" of AWWA, C 950 or equivalent. The maximum calculated long-term deflection should not exceed 3%. Copies of the design calculations shall be submitted to the Engineer for approval.

1. Stiffness: Minimum of 5,000 N/m2 for Gravity Pipelines in buried installation with cover depths less than 6 m. for Gravity Pipe lines in buried installation with cover depths more than 6 m and for minimum stiffness shall be 10000 N/m2. For all pressure and exposed pipelines, the minimum acceptable stiffness shall be 10000 N/m2.
2. Suitability of stiffness shall be verified for the various trench and pipe laying conditions and as recommended by the manufacturer.
3. Longitudinal Strength: To ASTM D 3262.
4. Hoop Strength: To ASTM D 3517.
5. Strain Corrosion Resistance: Tests are to be carried out as per ASTM D 3681 or BS 14364 strain corrosion value at 50 years to equal or exceed 0.7%.
6. Markings: To AWWA C950 Sec.6.1.

• Joints: GRP double socket couplings with rubber rings and joints are to meet the laboratory performance requirements of section 7 of ASTM D4161. Elastomeric gaskets shall conform to the requirements of ASTM F477.

Pipe Strength Test:

• At least one sample per 100 units shall be tested if the engineer wishes to subject it to maximum load testing according to ASTM C-497 Triple Load Method.?The pipes are rejected in case of breakage, defects, or roughness of the inner surface.

Pipe extension:

• The pipes inside the trench are lowered very carefully so that the pipes are not exposed to any damage and using a suitable lifter for hanging. The extension of the pipes continues with a smooth inclination of the tip and tail of the pipes in the direction of the flow rush belt and the levels of the pipes must be carefully controlled in order to match the plans and instructions of the engineer.
• As the work progresses, the inside of the sewer lines is cleaned of all dirt and the open ends of the pipes are closed. The maximum permissible deviation in horizontal line alignment for pipes that have been extended is 5 cm for a diameter of 500 mm and 8 cm for pipes with a diameter greater than 500 mm. If there is a subsidence in any pipe in a manner contrary to the plans or instructions of the engineer, this pipe must be re-extended without any additional expenses. A small piece (Short piece) of pipes is placed on both sides of the applicator and traps with a length of 50 cm or the diameter of the pipe, whichever is greater, and the installation is from the applicable to the applicator and it is not permissible to fill until after pouring the packaging concrete for the small piece. In the case of partial delivery of pipes due to the difficulty of implementation, a concrete aphasia is made around the pipe to maintain straightness and the level with a width of 20 cm and a thickness of 15 cm up to both ends of the drilling.
• In the case of laying pipes on a curve, the maximum bending limit for each joint is determined according to the manufacturer's recommendations.

Pipe mattress:

• A mattress is made for all pipes according to the plans with no less than a quarter of the outer pipe diameter (D/4) and a minimum of (15 cm) in clay soil, (20 cm) in rocky soil, and that the mattress type (B) is considered a normal mattress and of granular material conforming to the specifications of (ASTM C-33) insert 8 as shown below:

• The mattress material is approved by the engineer first, then the mattress material is placed at the bottom of the trench that has been examined by the secretariat representative, and the mattress is tamped with a hand tool so that its shape fits the bottom of the pipe. When the pipe is extended on the mattress, additional mattress materials are placed and tamped well with hand tools in successive layers not exceeding 15 cm thick until the level of the centre line of the pipe.
• When the trench is dug anywhere below the required level, the excess excavations are filled with the same mattress material if the excess depth in the excavation is within 20 cm, but if the excess work is more than that, the excess excavations must be filled. Class (C) concrete, and these fillings shall be at the expense of the contractor.

Concrete Packaging:

• The engineer's representative determines the locations and extent to which the pipeline needs additional protection by concrete packaging. The pipes must be placed in the approved trench with a proper level, slope and path, and the pipes must be installed in their places by means of a concrete block of an approved size. Concrete class (B) is carefully poured and moved around the pipe to obtain a solid homogeneous mattress around the pipe and in the required form according to the engineer's instructions.

Connections to current torrential sewer lines:

• When the new torrential lines are connected to the existing torrential drainage network, care must be taken to prevent the entry of dirt and waste into the existing torrent pipes, and the contractor provides the means of opening to facilitate the flow and discharge in the existing sewers and to maintain the trench in a dry state when connecting, as well as repairing any damage to the existing torrential streams in a way that satisfies the engineer.
• It must be ensured that the link between the new line and the old line is tightened by pouring a concrete block of class (B) from all sides and parties to ensure that water does not leak in the future. . The contractor must provide photos and video files before, during and after installation to ensure the quality of the works.
• The contractor shall treat the inner surface of the old ferry where the new line is met with a Grout mortar and ensure that the inner surface of the ferry is finished so that it matches the original surface. The contractor must provide photographs and video files before, during and after installation to ensure the quality of the works.

Horizontal drilling works:

• Horizontal drilling works are carried out when crossing highways and railway lines in accordance with the technical specifications and design plans, as the works include all materials necessary for the extension of pipelines, including the payment and reception rooms, and the contractor must coordinate with the competent authorities and everything necessary to complete the works.

Workshop Drawings (Workshop Plans):

• Four (4) sets of workshop fees must be prepared and submitted to the engineer for approval and production must not be started before receiving the engineer's approval and approval.
• The workshop fee must be complete including the drawings, manufacturing and installation details, connection and installation, properties and qualities of the materials.

Tolerances and finishes:

• The tolerance must meet the ACI 347 specification.
• The formed surfaces of precast concrete products must be factory finished. This means that the finishing of the casting units is natural as they are produced in moulds (such as iron) which give a smooth finish to the concrete.
• It is possible to bypass small surface holes resulting from air bubbles, and from the marks of natural mould joints, as directed by the engineer, but large defects, any damage or any structural defects should not be allowed. Capillary or shrinkage cracks with a maximum tolerance of 0.25 mm can be allowed if the shrinkage crack is wider than 0.25 mm, it must be rubbed, cleaned and filled with non-shrinkable and highly resistant epoxy with resinous fluid cement.
• If the crack passes through the cross section, this element must be rejected. The crack will be measured by a steel gauge (calibration plate) and reflective markings should be placed on the openings, their stations and the total length of the channel with the stations at intervals of 25 meters according to the approval of the engineer.?The maximum permissible tolerance in the upper and lower separators is not more than 6 mm and the width of the separators is not more than 20 mm.

Extensions and clamps:

• Sheets, lifting clamps, nails and plates cast in the installations shall be as detailed in the contract drawings, as indicated on the approved workshop drawings and as required for complete work.
• For fasteners installed in the field, they must be approved by the engineer in terms of quality and location.

Transportation and installation:

• Precast concrete parts must be raised and supported during manufacture and showing when the durability of concrete reaches 140 kg/cm2 and transportation and installation operations when it reaches the required durability of 350 kg/cm2 and using lifting and support points only, or both, as shown in the contract drawings and the approved workshop drawings. Transportation, on-site handling and installation must be carried out by equipment and methods acceptable to qualified personnel. Before installation, the contractor shall inspect all loading surfaces, places and alignment Materials and fastening materials cast in construction, noting that the correction of defects is the responsibility of the contractor.
• Balancing parts must be placed and aligned in their final position in the works, and the work will include but is not limited to the following:

1. Field welding, removal of lifting hooks, correction and adjustment of line and level, installation of sealing tools, mortar injection, plastering, laying of sealants and supply and laying of precast concrete for sealing tools and connections.
2. Fluid mortar should be brushed over the entire width of the upper surface of the wall elements before laying the elements of the upper tiles. Care must be taken against premature hardening.
3. For precast wall elements to be placed on concrete cushions or equivalent for level control, as well as all voids under the precast pieces must be injected with fluid mortar by pressure to ensure full loading. After the channel floor is tamped up 95% of the modified density of the proctor if the soil is suitable or replaced with a suitable new soil with a thickness of 15 cm.

BACKFILLING:

Materials used in backfilling:

• If the excavated materials are used in the backfill, they must be appropriately graded to give the required compaction and density and not contain any stones, rocks or concrete pieces.
• Borrowed materials: The borrowed materials used in the backfilling work must be good, clean, non-polluted and granular and must not contain more than 10% by weight of clay and silt together or individually.
• granular sand (unwashed sand): The sand must be free of impurities and organic matter, and its granular gradient must be within the following limits:

Backfilling around the installations:

Backfilling of pipe trenches and around manholes and assembly basins:

• No backfilling operations should begin until all unwanted materials have been removed from the trenches and written approval has been obtained from the engineer.
• The part of the trench, which starts from the middle of the pipe up to 30 cm above its upper surface, is backfilled with unwashed sand and handled to a density of not less than 90% of the maximum density according to the AASHTO T180/ASTM D1557?test, or 70% of the relative density, while for the part with a depth of 30 cm below the lower level of the asphalt pavement, it is backfilled in two layers with approved sub-foundation layer materials so that the thickness of each layer does not exceed 15 cm and is tamped to a density of no Less than 100% of the maximum density according to AASHTO T180/ASTM D1557, the part under the sub-foundation layer up to the upper surface of the unwashed sand should be backfilled with a layered material not exceeding 30 cm thick per layer and should be tamped to a density of not less than 95% of the maximum density according to AASHTO T180/ASTM D1557.?All density tests must be performed by ASTM 1557 modified proctor test.

Backfill test:

• Any source of backfill material must be tested to match the gradient and to determine other criteria required to determine field densities, and unless otherwise noted, the Sand Cone Test method shall be used to test field density and at least one test must be performed for successive layers between each section or in every 100 m. The use of bullets in backfilling is according to the following table:?

Stomach Type & Minimum backfill height over pipes

PRECAST CONCRETE MANHOLE:

Description: Reinforced precast concrete conforming to (ASTM) C478M with resilient pipe connectors conforming to ASTM C923M. (Rubber gasketed joints)

Joints for Precast Manholes and Structures:

• Conforming to ASTM C913.
• (Maximum Leakage: 94.6 ml per hour per 0.3 m of joint at 91 cm of head.)?

Ladders:

• Install ladders inside manholes and structures where indicated on drawings.
• Description: GRP ladder conforming to ASTM C478M and BS 4211, with an approved pattern, dimensions, and design to suit each installation as indicated on drawings.
• Fixation: Drill for wall fixing at both ends of ladder. Additional intermediate fixing connections shall be provided at centres not greater than 1.5 m apart. Fixings for ladders shall ·be approved stainless steel stud anchors. Fixings holes shall be grouted with epoxy mortar and sealed.
• Rungs: At 300 mm centres and at a distance not less than 150 mm from the wall. Rungs shall be ribbed to provide a non-slip surface. Each rung shall be able to withstand a point load of 1.5 kN.

Steps:

• Install steps inside manholes and structures where indicated on drawings.
• Description: Steps conforming to ASTM C478M and BS EN 13101.
• Material: Mild steel galvanized to ASTM A123M or BS EN ISO 1461 with 200 grams of zinc per square meter and covered with two layers of polyethylene (PE) or polypropylene.
• Formed integral with manhole sections.
• Diameter: 19 mm.
• Width: 300 mm.
• Spacing: 300 mm. vertically, set into structure wall.

FRAMES, COVERS, AND GRATES

• Construction: Ductile iron to ASTM A536 or BS EN 124.
• Surface: Machined flat bearing.
• Coating: Two component solvent free epoxy polyamine cured coating applied in two coats, each coat having a minimum dry film thickness of 200 microns.
• Lid: Removable and lockable.
• Covers shall be equipped with cast-in lifting eyes, holes or other handling facilities.
• Cover Design: Closed or vented or waterproof depending on location and approval of engineer.
• Cover: Includes sealing gasket.
• Grate Free Area: Approximately 50 percent minimum, unless otherwise indicated on drawings.
• Frames to be hinged to manhole/structure to ensure proper fixity.
• Covers and Grates: Moulded with identifying name and logo as approved by the Engineer
• Unless otherwise shown on drawings, live load rating shall be as follows:

1. For roadways, parking areas: AASHTO M306 Heavy Duty or BS EN 124 Class D400; non-rock type for wheel loads up to 11.5 tons. Minimum test load 400 kN.
2. For areas accessible to occasional vehicular traffic: AASHTO M306 Heavy Duty or BS EN 124 Class C250. Minimum test load 250 kN.
3. For sidewalks and areas not subject to vehicular traffic: AASHTO M306 Light Duty or BS EN 124 Class B125. Minimum test load 125 kN.

• Size: As indicated on the Drawings.
• Suitable lifting device for covers/grates to be provided at a rate of one device for every 10 units supplied with a minimum of one for each type of cover/grate.
• Multi-part utility structure covers and frames:

1. Ductile iron to ASTM A536 or BS EN 124, waterproof and non-rocking.
2. Covers shall be of the type incorporating integral removable intermediate beams to give the required clear opening shown on the drawings.
3. The complete system of covers, frames, and supporting metal work shall be designed to withstand the designated loading as specified above. The design of the multi-part cover system shall take into account the possibility of having multiple simultaneous point loads on the cover according to its overall dimensions and orientation. Design calculations shall be submitted to the Engineer for approval

• Covers and grates shall be sampled at random by the Engineer and load tested under his supervision according to AASHTO M306 or BS EN 124 procedures. The sampling and testing rate shall be typically 2%.

Waterproofing of Manhole/Structure External Surfaces:

• APP-Modified bituminous waterproofing sheet (tanking membrane) with protective board, smooth surfaced, and polyester reinforced.
• Number of layers: Two layers.
• Physical properties (tested to ASTM D5147M):

1. Thickness: 4.5 mm.
2. Tensile strength: 15.75 kN/m at minus 18?C in each direction.
3. Elongation at maximum load: 20% at minimum at minus 18?C in each direction.
4. Tear Strength: 378 N minimum.
5. Low-temperature flexibility: Pass at minus 10?C.

• The installation shall be performed according to manufacturer’s guidelines and a protection course should be installed over waterproofing membrane according to manufacturer’s written instructions and before beginning subsequent construction operations.
• Minimize exposure of the membrane.
• The Contractor shall provide a 10 year unconditional warranty against failure of all APPModified bituminous waterproofing membranes whether caused by defective materials or workmanship. The warranty shall be valid from the date of completion of the installation and must be handed to the Engineer before the issue of the Certificate of Completion.
• Epoxy Bituminous Lining of Manhole/Structure Interior:

1. Description: Coal tar epoxy paint, 70% epoxy and 30% coal tar.
2. Coating shall be applied to internal surfaces of manhole/structure by brush in accordance with manufacturer's instructions.
3. Minimum thickness: 1000 microns.

• Geotextile Filter Fabric:

1. Comply with AASHTO M288, for subsurface drainage and as specified in Section 310519.13

Watertight Manhole Cover Insert:

• Description: Manufactured of size to fit between manhole frame and cover and designed to prevent stormwater inflow. Includes handle for removal and gasket for gastight sealing.
• Material: HDPE meeting requirements of ASTM D1248, Class A, Category 5.
• Minimum thickness: 3.17 mm.

Installation:

• General: Install manholes/structures, complete with all applicable appurtenances and accessories indicated in drawings and/or specifications.
• B. Excavation and Backfill:

1. Excavate for manholes and structures as specified in Section 312316 - Excavation and in indicated locations and depths.
2. Provide clearance around sidewalls of manhole or structure for construction operations, granular backfill, and placement of geotextile filter fabric.
3. If groundwater is encountered, prevent accumulation of water in excavations; place manhole or structure in dry trench.
4. Where possibility exists of watertight manhole or structure becoming buoyant in flooded excavation, anchor manhole or structure to avoid flotation, as approved by Architect/Engineer

• Foundation Slab:

1. Place foundation slab and trowel top surface level.
2. Place manhole sections plumb and level, trim to correct elevations, and anchor to foundation slab.