464Reinforced Concrete Pipe

2.1 Fabrication . Multi- project fabrication plants, as defined in DMS -7305 , “Fabrication and Qualification

Procedure for Multi -Project Fabrication Plants of Precast Concrete Drainage Structures,” must be approved by the Materials and Tests Division in accordance with DMS -7305 before furnishing precast reinforced concrete pipe for Department projects. The Department’s MPL includes approved multi -project reinforced concrete pipe fabrication plants . Furnish material and fabricate reinforced concrete pipe in accordance with DMS -7305 .

2.2 Design .

2.2.1 General . The class and D -load equivalents are shown in Table 1. Furnish arch pipe in accordance with

ASTM C506 and the dimensions shown in Table 2. Furnish horizontal elliptical pipe in accordance with ASTM C507 and the dimensions shown in Table 3. For arch pipe and horizontal elliptical pipe, the minimum height of cover required is 1 ft. Table 1 Circular Pipe ASTM C76 and ASTM C655 Class D-Load I 800 II 1,000 III 1,350 IV 2,000 V 3,000 Table 2 Arch Pipe Design Size Equivalent Diameter (in.) Rise (in.) Span (in.) 1 18 13-1/2 22 2 21 15-1/2 26 3 24 18 28-1/2 4 30 22-1/2 36-1/4 5 36 26-5/8 43-3/4 6 42 31-5/16 51-1/8 7 48 36 58-1/2 8 54 40 65 9 60 45 73 10 72 54 88 Table 3 Horizontal Elliptical Pipe Design Size Equivalent Diameter (in.) Rise (in.) Span (in.) 0 15 12 19 1 18 14 23 2 24 19 30 3 27 22 34 4 30 24 38 5 33 27 42 6 36 29 45 7 39 32 49 8 42 34 53 9 48 38 60 10 54 43 68

2.2.2 Jacking, Boring, or Tunneling. Design pipe for jacking, boring, or tunneling considering the specific

installation conditions such as the soil conditions, installation methods, anticipated deflection angles, and jacking stresses. Provide design notes and drawings signed and sealed by a Texas licensed professional engineer when requested. Provide steel reinforcement in bell and spigot.

2.3 Marking . Furnish each section of reinforced concrete pipe marked with the following information in

accordance with DMS -7305 :  class or D -load of pipe,  ASTM designation,  date of manufacture,  pipe size,  name or trademark of fabricator and plant location,  designation “TX” for precast units fabricated in accordance with DMS -7305 ,  designated fabricator’s approval stamp for each approved unit,  pipe to be used for jacking and boring (when applicable), and  designation “SR” for pipe meeting sulfate- resistant concrete plan requirements (when applicable). Clearly mark one end of each section during the process of manufacture or immediately thereafter for pipe with elliptical reinforcement. Mark the pipe on the inside and outside of opposite walls to show the location of the top or bottom of the pipe as it should be installed unless the external shape of the pipe is such that the correct position of the top and bottom is obvious. Mark the pipe section by indenting or painting with waterproof paint.

2.4 Inspection . Provide access for inspection of the finished pipe at the project site before and during

installation.

2.5 Causes for Rejection . Individual sections of pipe may be rejected for any of the conditions stated in the

DMS -7305 Annex .

2.6 Repairs. Make repairs, if nec essary, in accordance with the DMS -7305 Annex .

2.7 Jointing Materials. Use any of the following materials for the making of joints unless otherwise shown on the plans. Furnish a manufacturer’s certificate of compliance for all jointing materials except mortar.

2.7.1 Mortar . Provide mortar for joints that meets the requirements of Section 464.3.3., “Jointing.”

2.7.2 Cold -Applied, Plastic Asphalt Sewer Joint Compound. Provide a material that consists of natural or

processed asphalt base, suitable volatile solvents, and inert filler. Ensure the consistency is such that the ends of the pipe can be coated with a layer of the compound up to 1/2 in. thick b y trowel. Provide a joint 722 compound that cures to a firm, stiff plastic condition after application. Provide a material of a uniform mixture. Stir any small separation found in the container into a uniform mix before using. Provide a material that meets the requirements shown in Table 4 when tested in accordance with Tex -526-C . Table 4 Cold -Applied, Plastic Asphalt Sewer Joint Compound Material Requirements Composition Analysis Asphalt base, 100% –% volatiles –% ash, % by weight 28–45 Volatiles, 212°F evaporation, 24 hr., % by weight 10–26 Mineral matter, determined as ash, % by weight 30–55 Consistency, cone penetration, 150 q, 5 sec., 77°F 150–275

2.7.3 Rubber Gaskets. Provide gaskets that conform to ASTM C1619 Class A or Class C. Meet the requirements

of ASTM C443 for design of the pipe joints and permissible variations in dimensions.

2.7.4 Pre-Formed Flexible Joint Sealants. Pre -formed flexible joint sealants may be used for sealing joints of

tongue- and-groove concrete pipe. Provide flexible joint sealants that meet the requirements of ASTM C990. Use flexible joint sealants that do not depend on oxidizing, evaporating, or chemical action for its adhesive or cohesive strength. Supply in extruded rope form of suitable cross -section. Provide a size of the pre- formed flexible joint sealant in con formance with the manufacturer’s recommendations and large enough to properly seal the joint. Protect flexible joint sealants with a suitable wrapper able to maintain the integrity of the jointing material when the wrapper is removed.

3.1 Excavati on, Shaping, Bedding, and Backfill . Excavate, shape, bed, and backfill in accordance with

Item 400, “Excavation and Backfill for Structures,” except where jacking, boring, or tunneling methods are permitted. Jack, bore, or tunnel the pipe in accordance wit h Item 476, “Jacking, Boring, or Tunneling Pipe or Box.” Immediate backfilling is permitted if joints consist of materials other than mortar. Take special precautions in placing and compacting the backfill to avoid any movement of the pipe or damage to the joints. Do not use heavy earth- moving equipment to haul over the structure until at least 4 ft. of permanent or temporary compacted fill has been placed over the structure, unless otherwise shown on the plans or permitted in writing. Remove and replace pipe damaged by the Contractor at no expense to the Department.

3.2 Laying Pipe . Start the laying of pipe on the bedding at the outlet end with the spigot or tongue end pointing

downstream and proceed toward the inlet end with the abutting sections properly matched, true to the established lines and grades unless otherwise authorized. Fit, match, and lay the pipe to form a smooth, uniform conduit. Cut cross trenches in the foundation to allow the barrel of the pipe to rest firmly on the bedding where bell -and-spi got pipe is used. Cut cross trenches no more than 2 in. larger than the bell ends of the pipe. Lower sections of pipe into the trench without damaging the pipe or disturbing the bedding and the sides of the trench. Carefully clean the ends of the pipe before the pipe is placed. Prevent earthen or bedding material from entering the pipe as it is laid. Lay the pipe in the trench, when elliptical pipe with circular reinforcing or circular pipe with elliptical reinforcing is used, so the markings for the top or bottom are not more than 5° from the vertical plane through the longitudinal axis of the pipe. Remove and re- lay, without extra compensation, pipe that is not in alignment or shows excessive settlement after laying. Lay multiple lines of reinforced concrete pipe with the centerlines of the individual barrels parallel. Use the clear distances between outer surfaces of adjacent pipes shown in Table 5 unless otherwise shown on the plans. Use the equivalent diameter from Table 2 or Table 3 for arch pipe or horizontal elliptical pipe to determine the clear distance requirement shown in Table 5. 723 Table 5 Minimum Clear Distance B etween Pipes Equivalent Diameter Min Clear Distance 18 in. 9 in. 24 in. 11 in. 30 in. 1 ft. 1 in. 36 in. 1 ft. 3 in. 42 in. 1 ft. 5 in. 48 in. 1 ft. 7 in. 54 in. 1 ft. 11 in. 60–84 in. 2 ft.

3.3 Jointing. Make available an appropriate rolling device similar to an automobile mechanic’s “creeper” for

conveyance through small -size pipe structures.

3.3.1 Joints Sealed with Hydraulic Cement Mortar . Use Type S mortar meeting the requirements of

ASTM C270. Clean and wet the pipe ends before making the joint. Plaster the lower half of the bell or groove and the upper half of the tongue or spigot with mortar. Pack mortar into the joint from both inside and outside the pipe after the pipes are tightly jointed. Finish the inside smooth and flush with adjacent joints of pipe. Form a bead of semicircular cross -section over tongue- and-groove joints outside the pipe, extending at least 1 in. on each side of the joint. Form the mortar for bell -and-spigot joints to a 45° fillet between the outer edge of the bell and the spigot. Cure mortar joints by keeping the joints wet for at least 48 hr. or until the backfill has been completed, whichever is first. Place fill or backfill once the mortar jointing material has cured for at least 6 hr. Conduct jointing only when the atmospheric temperature is above 40°F. Protect mortared joints against freezing by backfilling or other approved methods for at least 24 hr. Driveway culverts do not require mortar banding on the outside of the pipe. Furnish pipes, with approval, that are large enough for a person to enter with the groove between 1/2 in. and 3/4 in. longer than the tongue. Such pipe may be laid and backfilled without mortar joints. Clean the space on the interior of the pipe between the end of the tongue and the groove of all foreign material, thoroughly wet and fill with mortar around the entire circumference of the pipe, and finish flush after the backfilling has been completed.

3.3.2 Joints Using Cold- Applied, Plastic Asphalt Sewer Joint Compound. Ensure both ends of the pipes are

clean and dry. Trowel or otherwise place a 1/2- in. thick layer of the compound in the groove end of the pipe covering at least 2/3 of the joint face around the entire circumference. Shove home the tongue end of the next pipe with enough pressure to make a tight joint. Remove any excess mastic projecting into the pipe after the joint is made. Backfill after the joint has been inspected and approved.

3.3.3 Joints Using Rubber Gaskets. Make the joint assembly in conformance with the recommendations of the

gasket manufacturer. Make joints watertight when using rubber gaskets. Backfill after the joint has been inspected and approved.

3.3.4 Joints Using Pre -Formed Flexible Joint Sealants. Install pre -formed flexible joint sealants in conformance

with the manufacturer’s recommendations. Place the joint sealer so no dirt or other deleterious materials contact the joint sealing material. Pull or push home the pipe with enough force to properly seal the joint. Remove any joint material pushed out into the interior of the pipe that would tend to obstruct the flow. Store pre-formed flexible joint sealants in an area warmed naturally or art ificially to above 70°F in an approved manner when the atmospheric temperature is below 60°F. Apply flexible joint sealants to pipe joints immediately before placing pipe in trench, and connect pipe to previously laid pipe. Backfill after the joint has been inspected and approved.

3.4 Connections and Stub Ends . Make connections of concrete pipe to existing pipes, pipe storm drains, or

storm drain appurtenances as shown on the plans. 724 Mortar or concrete the bottom of existing structures if necessary to eliminate any drainage pockets created by the connections. Repair any damage to the existing structure resulting from making the connections. Make connections between concrete pipe and corrugated metal pipe with a suitable concrete collar and a minimum thickness of 4 in. unless otherwise shown on the plans . Finish stub ends for connections to future work not shown on the plans by installing watertight plugs into the free end of the pipe. Fill lift holes with concrete, mortar, or precast concrete plugs after the pipe is in place .