1020.2.1 Corrugated Metallic-Coated Steel Culvert Pipe

Corrugated metallic-coated steel culvert pipe, pipe-arches, couplings and end sections are to be accepted on the basis of the sheet or coil manufacturer having filed the required documents set forth in the specifications, the plant being approved and qualified, certification by the manufacturer, manufacturer quality control documentation, identification marking, random sampling and testing and field inspection.

1020.2.1.1 Manufacturer Approval

Metal and Concrete Pipe

Report 2008
See also: Research Publications

Prior to acceptance of corrugated metallic-coated steel culvert pipe, pipe-arches, couplings and end sections, the manufacturer shall have furnished Construction and Materials a Quality Control Plan as required by Sec 1020, a statement certifying that fabrication will be in accordance with the QC plan, a list of the sources of material used in fabrication, and a statement guaranteeing that all material used in fabrication will be in accordance with the applicable specification.

A list of those manufacturers who have filed acceptable documents is shown in Qualified Fabricators of Corrugated Metallic-Coated Steel Culvert Pipe, Pipe-Arches and End Sections.

End sections should not be accepted without a qualified manufacturers Quality Control stamp. Suppliers that purchase end sections from manufacturers of end sections, not listed in Qualified Fabricators of Corrugated Metallic-Coated Steel Culvert Pipe, Pipe-Arches and End Sections, may perform a QC inspection and mark with their QC stamp for acceptance. The facility that QC-stamps the end section shall be held responsible for specification compliance. End sections should be purchased from a manufacturer listed in Qualified Fabricators of Corrugated Metallic-Coated Steel Culvert Pipe, Pipe-Arches and End Sections whenever possible. Manufacturers that wish to supply end sections will be notified of the requirements stated in 1020.2.1.1.

During any visit to the manufacturer, the manufacturer’s records shall be reviewed for test result and inspection documentation. The records shall be specific to each shipment of pipe and shall indicate the purchase order number or project number, route, county, date of inspection, quantity (ft or m), pipe diameter, number of couplings and end sections.

If a manufacturer is found not to be in compliance with the specifications, notify Construction and Materials so the manufacturer’s approval can be reconsidered.

If the manufacturer is found falsifying documentation, Construction and Materials is to be notified immediately for removal of that manufacturer or plant from the approval list.

1020.2.1.2 Sheet Manufacturer's Certified Analysis and Guarantee

Prior to the acceptance of corrugated metallic-coated steel for culvert pipe, pipe-arches and end sections, the sheet or coil manufacturer shall furnish Construction and Materials a Sheet Manufacturer's Certified Analysis and Sheet Manufacturer's Guarantee as required by Sec 1020. A list of those manufacturers who have filed acceptable documents is shown in Qualified Brands and Manufacturers of Galvanized (Zinc-Coated) Steel Sheet and Qualified Brands and Manufacturers of Aluminum Coated Steel Sheet. Manufacturers with plants at multiple locations must submit the documentation for each location they wish to have on the approved list.

If random sampling results in the rejection of the metal, acceptance on the basis of sheet manufacturer's certified analysis and guarantee shall immediately be discontinued and all culvert metal of that brand and gage shall then be sampled, tested, and approved prior to use until such time as shall be determined by Construction and Materials. Construction and Materials will advise all districts should acceptance of a brand or gage by sheet manufacturer's certified analysis and guarantee be discontinued. When test results again indicate consistent compliance to specification requirements, the State Construction and Materials Engineer will notify all districts to reinstate that brand and/or gage to the approved list of manufacturers.

1020.2.2 Material

1020.2.2.1 Steel Sheet

The steel sheet used for fabrication shall be coated on both sides by the hot dip process with zinc or aluminum in accordance with AASHTO M 218 or AASHTO M 274 and the requirements specified herein. The coated steel sheet may be furnished flat in coils or cut lengths or corrugated in cut lengths. The steel sheet may be sheared to proper size after coating. Furnished steel shall be free from injurious defects such as blisters, flux and uncoated spots.

1020.2.2.1.1 Chemical Composition

The base metal composition of the steel sheet shall comply with the requirements AASHTO M 36 (see Table 1020.4.1 Chemical Composition by Cast Analysis).

1020.2.2.1.2 Mechanical Properties

The metallic coated steel when tested in the longitudinal direction of steel sheets prior to corrugation or other fabrication shall comply with the requirements of AASHTO M 36 (see Table 1020.4.2 Tensile Requirements). Steel sheet tested after corrugating or other fabrication shall conform to the tensile and yield strength requirements of AASHTO M 36 (see Table 1020.4.2 Tensile Requirements) but the elongation will not be required.

1020.2.2.1.3 Thickness

Sheet thickness shall conform to the dimensions specified in AASHTO M 36 (see Table 1020.4.3 Specified Thickness, Equivalent Gage, and Minimum Thickness). The thickness of the sheet includes both the steel and the coating.

1020.2.2.1.4 Corrugations

The dimensions of the corrugations shall be in accordance with AASHTO M 36 (see Table 1020.4.4 Corrugation Size). Corrugations shall form smooth continuous curves and tangents.

1020.2.2.1.5 Width

Covering width of corrugated cut lengths shall be in accordance with AASHTO M 36 (see Table 1020.4.5 Covering Width). Covering width is the distance between the crests of the outermost corrugations. There is no established tolerance for overall width since the covering width and lip dimensions are the governing factors for the formed product.

1020.2.2.1.6 Edge Lip

Lip dimensions of corrugated cut lengths shall be in accordance with AASHTO M 36 (see Table 1020.4.6 Edge Lip Dimensions). The lip dimension is measured along the radial curvature from the crest of the outermost corrugation to the edge of the sheet.

1020.2.2.1.7 Zinc Coating

Refer to Sec 1020.3.2.

1020.2.2.1.8 Aluminum Coating

Refer to Sec 1020.3.3.

1020.2.2.2 Rivets

The rivets used in riveted fabrication shall be of the same material as the base metal specified in the steel sheet. They shall be thoroughly galvanized and sherardized.

1020.2.2.3 Bolts and Nuts

Bolts, nuts, and other threaded articles used with coupling bands and end sections and other hardware items used with coupling bands, shall be coated by one of the processes specified in AASHTO M 36.

1020.2.3 Identification Markings for Steel Sheet

Each sheet or coil of corrugated metallic-coated steel is to be clearly marked, in accordance with AASHTO M 36, at intervals of 2 to 5 ft. (600 to 1500 mm) by the manufacturer with a weather resistant stamp and the marking is to contain the name of the sheet manufacturer, brand, gage number or thickness, specified weight (mass) of coating, type of coating or AASHTO designation number of the coated steel and identification symbols showing heat number and coating lot designation. The pipe shall be fabricated in such a way that the markings appear on the outside of the pipe. Remarking of material that was mis-marked is allowed if the original marking is removed, obliterated, or otherwise clearly indicated as incorrect. Only sheets or coils from the manufacturers listed in Qualified Brands and Manufacturers of Galvanized (Zinc-Coated) Steel Sheet and Qualified Brands and Manufacturers of Aluminum Coated Steel Sheet are to be accepted.

1020.2.4 Random Sampling of Steel Sheet

Random samples are to be submitted to the Laboratory for determination of weight (mass) of coating, mechanical properties and chemical analysis. Samples may be taken at the point of manufacture, intermediate distribution point or at the project. A lot shall be considered that quantity of material offered for inspection at one time that is of the same thickness and bears the same heat number and coating lot designation. In addition to sampling, field thickness measurement, and pitch and depth of corrugation measurements shall be made on the same sheets or coils selected for random sampling.

Samples for determination of weight (mass) of coating are to be submitted to the Laboratory from 5 to 10 percent of the lots of sheets or coils of each gage inspected and shall be obtained from sheets or coils before or after fabrication of the culvert pipe, pipe-arch or end sections except that end sections may be fabricated at a location where inspection is not normally done, in which case the weight (mass) of coating may be determined by magnetic or electronic gauge readings taken on the fabricated units. The magnetic or electronic gauge is to be operated and calibrated in accordance with ASTM E 376.

Single-Spot Test. A single-spot test by magnetic or electronic gauge is to be comprised of at least five readings in a small area and those readings averaged to obtain a single-spot test result. Three such areas should be tested on each side of the unit being tested. This would yield six single-spot test results for an end section in that lot. Average the six single spot test results to obtain the average coating weight (mass) for that unit. Test each unit selected, in the same manner. Average all single-spot test results from each lot tested to obtain the average coating weight (mass) to be reported. Since the specified coating weight (mass) is for double exposed surfaces, the average coating weight (mass) obtained is to be doubled so the reported test result can be directly applied to the specifications. Also report the minimum coating weight (mass) which would be the lowest average coating found on one unit from a single lot.

Material may be accepted or rejected for metallic coating on the basis of magnetic or electronic gauge results. If a test result on an individual unit or the average test result on all units fails to comply with the requirements of the specifications, that lot should be resampled at double the original sampling rate. If any of the resample specimens fail to comply with the specifications, the material may be rejected or samples may be submitted to the Laboratory.

Corrugated metallic-coated steel sheets are to be sampled for weight (mass) of coating at the rate shown in EPG 1020.6 Sampling Corrugated Metallic-Coated Steel Sheets . Three specimens from one sheet comprise one sample. Each specimen shall not be less than 3 in. x 6 in. (75 x 150 mm) in size, or equivalent area. Each specimen shall be taken so no part includes metal closer than 2 in. (50 mm) from an edge or 4 in. (100 mm) from an end of the sheet. Samples are to be taken from the selected sheets in accordance with one of the following patterns:

(a) One specimen shall be obtained from the center of the sheet and the other two from diagonally opposite corners.

(b) The specimens shall be taken from one end of a sheet, one from the middle portion and one from near each edge. Instead of three specimens, the sample as submitted to the Laboratory may consist of one piece not less than 3 in. (75 mm) wide by the full width of the sheet.

The sample for testing weight (mass) of coating of coils shall consist of three specimens taken from one end of a coil. One specimen not less than 3 in. x 6 in. (75 x 150 mm) shall be cut from the middle of the width and one from each side not closer than 2 in.(50 mm) from the side edge or 4 in. (100 mm) from the end. Instead of three specimens, the sample as submitted to the Laboratory may consist of one piece approximately one foot (300 mm) long by the as-coated width, taken at least 4 in. from the end of a sheet or coil.

If laboratory test results show the metal fails to meet the requirements for coating, the lot shall be resampled using pattern (a) unless one of the specimens has less than 1.80 ounces (550 gm/m²) of galvanizing per square foot (meter) of double exposed surface or 0.90 ounce (275 gm/m²) of aluminum coating per square foot (meter) of double exposed surface in which case the lot shall be rejected without re-sampling. Samples for retest of coils shall be obtained in the same manner as for the original test.

Samples for Chemical Analysis. Samples for chemical analysis of the base metal of sheets or coils before fabrication are to be taken at approximately one-year intervals for each brand and kind of metal presented for inspection. Each specimen shall not be less than 3 in. x 6 in. (75 x 150 mm) in size, or equivalent area and each specimen shall be cut from different sheets in a lot. The number of sheets from which specimens are to be taken for chemical analysis shall be as shown in Table 1020.7 Sampling Base Metal Sheets or Coils. Samples of coils shall consist of three specimens from a coil or if more than one mill (25 μm) lift or coil is involved, three specimens shall be selected from each of at least two different coils.

Samples for determination of mechanical properties of the base metal of sheets or coils are to be taken at approximately one-year intervals for each brand and kind of metal presented for inspection. Two specimens, each 4 in. x 14 in. (100 x 355 mm), shall be taken from one end of the cut length or coil. The 14-in. dimension shall be in the longitudinal direction of the steel sheet. No specimen shall be taken closer than 2 in. (50 mm) from the edge or 4 in. (100 mm) from the end of a sheet or coil.


	Refer to paragraph above
	Refer to paragraph below

Field measurements for gage, pitch and depth of corrugations are to be made on the same sheets or coils selected for random sampling. A minimum of five gage thickness measurements shall be taken across the width of the sheet or coil at an end at least 3/8 in. (10 mm) from the edge of the metal and on the tangents of corrugations. Two of these measurements shall be on the outermost full corrugations, or within 2 in. (50 mm) of each side edge of coils. If any single measurement is found deficient more than the specified tolerance, that sheet or section of coil is to be rejected. Additional sheets or sections of coil are to be measured until it is established the remainder of the metal is of satisfactory thickness or until it is evident that a substantial portion (approximately ten percent of the measured sheets or ten percent of the length of the coil) of the lot is deficient, in which case the lot shall be rejected. Rejection and retesting for corrugation pitch or depth is the same as for field thickness.

1020.2.5 Field Inspection

Field inspection shall be performed using the EPG 1020.5 Corrugated Metal Pipe (CMP) Inspection Guide. Frequency of field inspection of completed pipe shall be at the discretion of the engineer, but shall be performed on approximately 10 percent of shipments and a minimum of once per month.

The manufacturer shall specify in their application for placement on the qualified list to which standards their pipe is fabricated; English or metric. The standard fabrication units will be designated on the Qualified Fabricators of Corrugated Metallic-Coated Steel Culvert Pipe, Pipe-Arches and End Sections for each manufacturer. All measurements shall be made using the applicable units when determining compliance with specification.

Pipe supplied by local manufacturers will be inspected at the manufacturer’s plant by the district in which the plant is located. Pipe supplied by out-of-state manufacturers will be inspected at the destination by the district in which the destination is located. Construction and Materials will maintain records of when sampling and inspection of out-of-state pipe shall be performed and notify the district to do so.

1020.2.5.1 Mill and Factory Inspection

The engineer may have the sheet steel inspected and sampled in the rolling mill or in the shop where pipe is fabricated. The engineer may require from the mill the chemical analysis of any heat. The inspection, either in the mill or in the shop, shall be under the direction of the engineer. The engineer shall have free access to the mill or shop for inspection and every facility shall be extended for the purpose of inspection. Any sheet steel or pipe that has been previously rejected at the mill or shop and included in a later lot will be considered sufficient cause for rejection of the entire lot.

Fabricated metallic-coated steel pipe or end sections are to be marked as described in EPG 1020.2.3 Identification Markings for Steel Sheet. The brand of base metal is to be checked to verify that it is on the list of pre-qualified brands, Qualified Brands and Manufacturers of Galvanized (Zinc-Coated) Steel Sheet and Qualified Brands and Manufacturers of Aluminum Coated Steel Sheet. The markings on end sections may not appear in a uniform manner since the sheets are cut and formed before assembling the unit, however, the markings can usually be determined through careful inspection. Due to the frequency of sheet metal brand marking, particularly small end sections may occasionally be fabricated without any indication of the original marking. It is satisfactory to accept those occasional units when the fabricator has re-marked the sheet indicating its origin, providing it is reasonable and consistent with the other comparable units being furnished and inspected, and meets all other specifications.

Field inspection of fabrication includes random spot-checking for weight (mass) of coating and thickness in accordance with ASTM E 376, checking diameter, length, shape, width of lap, rivet size, rivet or spot weld spacing, integrity of lock seams and weld seams, end finish - if required, workmanship and methods of riveting or qualification of welding machine and operator if resistance spot welding is being used, inspection of tests performed by the manufacturer on helical weld seams and tension tests on helical lock seams if performed by the manufacturer. The tolerances and requirements are described in detail in Sec 1020 and AASHTO M 36. Per ASTM A924 Appendix X3 Guide To Conversion Between Coating Weight (Mass) and Thickness, Table X3.3 states one ounce of zinc per square foot equals 1.68 mils and Table X3.2 states for Type 2 one ounce of aluminum per square foot equals 3.74 mils. For zinc galvanized coating, if any single spot is found to be lower than 1.51 mils (0.9 oz. per square foot) on a single side or the average of all singles spots on a single side is found to be lower than 1.68 mils (1 oz. per square foot), that pipe is to be rejected. For aluminized coating, if any single spot on a single side is found to be lower than 1.68 mils (0.45 oz. per square foot) on a single side or the average of all single spots on a single side is found to be lower than 1.87 mils (0.5 oz. per square foot), that pipe is to be rejected. Additional pipe should be measured until it is established that the remainder of the pipe is of satisfactory fabrication and workmanship or until it is evident that a substantial portion of the lot is deficient (approximately ten percent of the measured pipe), in which case the entire lot or shipment shall be rejected.

The specified inside diameter, in accordance with AASHTO M 36, shall not vary more than 1 percent or 0.5 in. (13 mm), which ever is greater. A summary of the diameter tolerance can be seen in Table 1020.4.11 Diameter Dimensional Tolerances (English) and Table 1020.4.12 Diameter Dimensional Tolerances (Metric). All measurements shall be made using the same units to which the pipe was fabricated.

The specified inside diameter, in accordance with Sec 725, shall not be reduced by more than 10 percent by deflection when installed and measured at the narrowest point. All pipe installed shall be tested for deflection.

Visual examination of lock seam shall be performed every time field inspection is performed using the EPG 1020.5 Corrugated Metal Pipe (CMP) Inspection Guide. Samples for visual examination of lock seam pipe shall be triangular sections taken from one end of a length of pipe so as to show the cross section normal to the seam. The base of the triangular sample shall be of sufficient width to show the complete lock seam profile. This sample shall meet the profile as described in AASHTO T 249.

Samples for tension tests of lock seam pipe shall be taken from pipe representing each sheet thickness and diameter the first time that sheet thickness and diameter is offered for inspection. Approximately 10 percent of the shipments of each sheet thickness thereafter shall be sampled for tension testing of the seam. The sample shall consist of a 4 in. x 8 in. (100 x 200 mm) strip taken from the end of a fabricated pipe. A 1 in. x 8 in. (25 x 200 mm) coupon perpendicular to the lock seam will be saw-cut from the sample. The edges of the coupon will be parallel. No reformed corrugations will be allowed in the sample. The length perpendicular to the lock seam shall be a minimum of 8 in. (200 mm). Tension test specimens may be sent to the Central Laboratory for testing or they may be tested at the plant providing proper equipment is available. The sample shall meet the tension requirements noted in AASHTO M 36 (see Table 1020.4.17 Tensile Strength of Lock Seams).

Pipe that has been rejected at the origin shall be marked with a small, filled circle or orange paint on the inside of the barrel, in the downstream end. The pipe is subject to inspection and rejection at destination for any damage that may have occurred in handling. Pipe that is rejected at destination shall be marked in the same manner as pipe rejected at the origin. The inspector may choose to mark inspected pipe to prevent inspection of the same pipe more than once. However, the in.MoDOT – OK in. stamp should not be used.

If pipe is rejected for not being in accordance with specifications and the requirements set forth in the EPG 1020.5 Corrugated Metal Pipe (CMP) Inspection Guide, a letter documenting the failure shall be provided to the manufacturer, with a copy to Construction and Materials. The inspection guide used to inspect the rejected pipe shall be included with the letter to the manufacturer and Construction and Materials. The letter should include the location of the plant at which the failure occurred.

1020.2.6 Fabrication

1020.2.6.1 Shape

Pipe shall be a full circle or pipe arch in accordance with Table 1020.4.9 Pipe-Arch Requirements or Table 1020.4.10 Pipe-Arch Requirements or the shape as shown on the plans. Pipe shall be fabricated with circumferential corrugations and with riveted or resistance spot-welded lap joint construction or with helical corrugations with a continuous lock or welded seam extending from end to end of each length of pipe. Pipe arch shall consist of corrugated metal pipe, that has been reformed to multi circle pipe having arch shaped tops with slightly outwardly centered integral bottoms.

1020.2.6.2 Corrugations

Corrugations shall form smooth continuous curves and tangents. The corrugations shall be either annular or helical. The direction of the crests and valleys of helical corrugations shall not be less than 60 degrees from the axis of the pipe for pipe diameters larger than 21 in. (525 mm) and less than 45 degrees from the axis for pipe diameters of 21 in. (525 mm) and smaller.

1020.2.6.3 Dimensions

The diameters, width of laps, sheet thickness, specified corrugation and dimensions of pipe and pipe arch shall be as shown in Table 1020.4.8 Pipe Requirements, Table 1020.4.9 Pipe-Arch Requirements and Table 1020.4.10 Pipe-Arch Requirements.

1020.2.6.4 Riveted Seams

Riveted longitudinal seams shall be staggered to the extent that no more than three thicknesses of steel sheet are fastened by any rivet. The longitudinal seams shall be located within 120 degrees of arc for pipe of 36 in. (900 mm) diameter or less and within 240 degrees of arc for pipe larger than 36 in. (900 mm) diameter, so that pipe may be installed without longitudinal seams in the invert. In any case, a longitudinal seam will not be allowed on the corner radius of pipe arch.

The size of rivets shall be as shown in Table 1020.4.15 Riveted and Spot Welded Seams, for the sheet thickness and corrugation size designated. The width of lap shall be as shown in Table 1020.4.8 Pipe Requirements. Circumferential seams shall have a maximum rivet spacing of 6 in. (150 mm), measured on centers, except that six rivets will be sufficient for 12 in. (300 mm) diameter pipe. Longitudinal seams of pipe with 1/2 in. (13 mm) deep corrugations shall be riveted with one rivet per corrugation on pipe 36 in. (900 mm) or less in diameter and with two rivets per corrugation on pipe 42 in. (1050 mm) or more in diameter. All sizes of pipe having one inch (25 mm) deep corrugations shall have two rivets per corrugation.

All rivets shall be driven cold in such a manner that the steel sheet shall be drawn tightly together throughout the entire lap. All rivets shall be placed in the valley of the corrugation. The center of a rivet shall be no closer than twice its diameter from the edge of the sheet. All rivets shall have neat, workmanlike and full hemispherical heads or heads of a form acceptable to the engineer, shall be driven without bending and shall completely fill the hole.

1020.2.6.5 Helical Lock Seams

Continuous helical lock seams shall be formed in the tangent element of the corrugation profile with its center near the neutral axis of the corrugation profile.

The edges of the steel sheet within the cross section of the lock seam shall lap at least 5/16 in. (8 mm) with an occasional tolerance of minus 10 percent of lap width allowable. The lapped surfaces shall be in tight contact.

The profile of the steel sheet shall include a retaining offset adjacent to the 180-degree fold, as described in AASHTO T 249, of one sheet thickness on one side of the lock seam or one-half sheet thickness on both sides of the lock seam.

There shall be no visible cracks in the metal, loss of metal-to-metal contact or excessive angularity on the interior of the 180-degree fold of metal of finished lock seams.

The minimum tensile strength, in pounds force (kilonewtons), as determined on specimens cut from fabricated pipe normal to and across the lock seam shall be as shown in Table 1020.4.17 Tensile Strength of Lock Seams.

When the ends of helically corrugated lock seam pipe have been re-rolled to form annular corrugations, the lock seam in the re-rolled end shall not contain any visible cracks in the base metal and the tensile strength of the lock seam shall not be less than 60 percent of that required in Table 1020.4.17 Tensile Strength of Lock Seams.

1020.2.6.5.1 Sampling

Sampling and testing for continuous lock seam quality control shall conform to AASHTO T 249. The fabricator shall cut all samples in the presence of the engineer. Visual examination samples shall be cut from at least one pipe of each sheet thickness in each shipment of pipe offered for inspection. In addition, tension test specimens shall be taken from pipe representing each sheet thickness and diameter the first time that sheet thickness and diameter is offered for inspection. Approximately 10 percent of the shipments of each sheet thickness thereafter shall be sampled for tension testing of the seam. If visual examination samples indicate nonconformance, that length of the pipe will be rejected and a resample taken from a different length of pipe of the same sheet thickness of the same diameter. If the resample fails, each shipment of that sheet thickness thereafter shall be sampled for visual examination and tension testing until the engineer determines that satisfactory quality control is established. Pipe from which tension test specimens have been taken may be cut and the undamaged portion accepted for use.

1020.2.6.6 Shop Elongation

If round pipe is required to be shop elongated, the vertical axis shall be 5 percent greater than the nominal diameter. A tolerance of one percentage point in elongation will be permitted. Approximately 2 ft. (600 mm) at each end of an installation may be left round to accommodate connecting end treatments or extensions. A paint mark to indicate the top of pipe shall be placed on each piece of shop elongated pipe and round ends on an elongated pipe shall be clearly marked in.Outside End-Round in..

1020.2.6.7 End Finish

Rolled or otherwise reinforced ends will not be required for pipe or pipe-arches.

Beveled Ends. Corrugated metal pipe shown on the plans as having the ends beveled to conform to the adjacent roadway slope shall be cut in such a manner as to leave smooth edges without damage to the coating away from the edges. Cut edges shall be completely covered with two coats of single component inorganic zinc or organic zinc-rich paint meeting the approval of the engineer. No other end finish will be required for pipe having beveled ends.

The ends of individual lengths of pipe with helical corrugations may be re-rolled to form annular corrugations extending at least two corrugations from the pipe end.

1020.2.6.8 End Sections

Metal end sections shall comply with the requirements for base metal, coating, fabrication, sampling, accepted brands of metal, sheet manufacturer's certified analysis, sheet manufacturer's guarantee, sheet thickness, workmanship and repair of coating. The sections shall conform to the shape, dimensions and sheet thicknesses shown on the plans.

1020.2.6.9 Coupling Bands

Field joints for each type of corrugated steel pipe shall provide circumferential and longitudinal strength to maintain the pipe alignment, prevent separation of pipe and prevent infiltration of fill material. The coupling bands shall be made of base metal complying with the requirements for steel sheets and shall have the same coating as the sheet used in fabrication of the pipe. Coupling bands shall be not more than three guage thicknesses lighter than the guage of the pipe to be connected and in no case lighter than 18 guage. Corrugations in the bands shall have the same dimensions as the corrugations in the pipe ends being connected. Coupling bands may be circumferentially corrugated bands, bands with projections (dimples), formed bands or helical bands.

Bands with projections (dimples) may be used on pipe with annular or helical corrugations. The projections shall conform substantially to the shape and depth of the pipe corrugations and shall be in circumferential rows with one projection for each corrugation of helically corrugated pipe. The bands for pipe diameters to 72 inches (1800 mm), inclusive, shall be at least 10 1/2 in. (265 mm) wide and shall have two circumferential rows of projections; and for pipe diameters 78 inches (1950 mm) and greater the bands shall be at least 16 ¼ in. (415 mm) wide and shall have four circumferential rows of projections. Rows of projections shall be spaced to provide equal contact on each of the pipe being joined.

Formed bands may be used on pipe with annular corrugations and helically corrugated pipe with reformed ends. The bands shall be formed with two corrugations matching the profile of the pipe being joined together. The corrugations shall be spaced to provide seating in the second corrugation of each pipe and without creating more than 1/2 in. (13 mm) annular space between the pipe ends when joined together.

Helical bands for use on helically corrugated pipe shall be not less than 12 in. (300 mm) wide for 1/2 in. (13 mm) deep corrugations and not less than 14 in. (350 mm) wide for one-inch (25 mm) deep corrugations.

Circumferentially corrugated bands, bands with projections and helically corrugated bands shall be so constructed as to lap on an equal portion of each of the culvert sections and shall be connected at the ends by galvanized angles having minimum dimensions of 2 in. x 2 in. x 3/16 in. (50 x 50 x 5 mm), fastened with galvanized bolts of ½ in. (13 mm) minimum diameter. Formed bands shall be fastened together by two ½ in. (13 mm) bolts through the use of a bar and strap welded to the band. Angles shall be secured to the coupling bands by riveting or resistance spot welding at each corrugation. Rivets shall be placed so that the head of the rivet will be on the inside of the band. Welds shall be painted with one coat of zinc dust-zinc oxide or zinc-rich paint meeting the approval of the engineer. The 7 in. and 10 ½ in. (180 mm and 254 mm) bands shall have at least two fastening bolts, the 12 in. and 14 in. (300 mm and 350 mm) bands shall have at least three fastening bolts and the 16 ¼ in. (415 mm) band shall have at least four fastening bolts. Alternate methods of fastening the ends of coupling bands may be used if approved by the engineer. Coupling bands for pipe-arch and shop elongated pipe shall be shaped to fit the structure.

In lieu of coupling bands, a bell and spigot joint system may be used as approved by Construction and Materials.

As described in Sec 1020.4.6.1, coupling bands may be closed using standard angle or by approved alternatives. The Materials Field Office approves the use of engineered stamped angles for closing bands. Engineered stamped angles will be at least 12 gauge metal and have deformations designed to strengthen and maintain the 90° shape.

1020.2.6.10 Special Fittings

Special fittings, angles and tees shown on the plans shall be fabricated by welding in such a manner as to avoid excessive damage to the coating away from the welded area. The welded area and adjacent damaged coating shall be repaired in accordance with EPG 1020.2.7.2 Repair of Damaged Coating.

1020.2.7 Workmanship and Finish

1020.2.7.1 Workmanship

In addition to the requirements of fabrication, the completed pipe, bands, fittings or end sections shall show careful, finished workmanship in all particulars. Any item on which the coating has been bruised or broken either in the shop or in shipping or which shows defective workmanship, will be rejected. This requirement applies not only to the individual item, but to the shipment on any contract as a whole. Among others, the following defects are specified as constituting poor workmanship and the presence of any or all of them in any individual pipe, band, fitting, end section or in general in any shipment will constitute sufficient cause for rejection:

(a) Variation from a straight centerline.

(b) Elliptical shape in pipe intended to be round.

(c) Metallic coating which has been bruised, broken or otherwise damaged.

(d) Lack of rigidity.

(e) Illegible markings.

(f) Ragged or diagonal sheared edges or ends.

(g) Uneven laps in riveted or spot welded pipe.

(h) Poorly formed rivet heads.

(i) Loose, unevenly lined or unevenly spaced rivets or spot welds.

(j) Defective spot welds or continuous welds.

(k) Dents or bends in the metal.

(l) Loosely or poorly formed lock seams.

1020.2.7.2 Repair of Damaged Coating

Units on which the metallic coating has been burned by welding beyond the limits provided in EPG 1020.2.6.5 Helical Lock Seams and EPG 1020.2.6.7 End Finish or has been otherwise damaged in fabrication or handling, shall be repaired. The repair shall be done so the completed unit shows careful finished workmanship in all particulars. If the engineer so elects, the repair shall be done in the presence of the engineer. In any case, the material used and the application shall meet the approval of the engineer.

Coating damaged during fabrication or handling in the fabricating shop shall be repaired by recoating by the hot-dip process, by the metallizing process or with two coats of single component inorganic zinc or organic zinc-rich paint, meeting the approval of the engineer.

Coating damaged in the field shall be repaired by recoating by the hot-dip process or by the metallizing process except that in instances of minor damage to areas in the upper two-thirds of the perimeter as installed, the engineer may permit repair in the same manner as specified for repair during fabrication. The fabricated unit shall be thoroughly cleaned prior to recoating. The hot-dip process shall be in accordance with EPG 1020.2.2 Material.

Damaged Areas. Damaged areas shall be cleaned to bright metal by blast cleaning, power disk sanding or wire brushing. The cleaned area shall extend at least 1/2 in. (13 mm) into the undamaged section of the coating. The cleaned area shall be coated within 24 hours and before any rusting or soiling.

1020.2.7.2.1 Repair By Painting

The type of paint repair may be any one of those specified above. Paint shall be applied over the damaged section and surrounding cleaned undamaged area. Any of the allowed repair paint systems may be used for repair of zinc or aluminum coatings.

1020.2.7.2.2 Repair By Hot-Dip Process

The fabricated unit shall be thoroughly cleaned prior to recoating. The metallic coating shall then be applied by the hot-dip process in accordance with EPG 1020.2.2 Material.

1020.2.7.2.3 Repair By Metallizing Process

The damaged area shall be cleaned as described in Damaged Areas except the damaged area shall be cleaned to the near-white condition. The repair coating applied to the cleaned section shall have a thickness of not less than 0.005 in. (0.13 mm) over the damaged section and shall taper off to zero thickness at the edges of the cleaned undamaged section.

When zinc coating is to be metallized, the process shall be done with zinc wire containing not less than 99.98 percent zinc.

When aluminum coating is to be metallized, the process shall be done with aluminum wire containing not less than 99 percent aluminum.

1020.2.8 Handling

Proper care shall be exercised in loading, transporting, unloading and delivering the pipe to the construction site and in its placement. When nesting pipe or loading pipe, boards or other suitable material, running the full length of the pipe shall be used to prevent metal from rubbing or resting against metal and to prevent damage to the pipe. Special care shall be exercised in preventing the rivets from scratching adjacent pipe. Chains or metal cables used in binding the load and unloading shall be encased to prevent damaging the pipe or suitable material shall be fastened securely between the pipe and chains or cable. Wood skids or other approved devices shall be used in loading and unloading the pipe. Metal lever bars will not be permitted in loading and unloading. Dragging the pipe across rocky ground or dragging the pipe in such manner as to cause gouging or removal of coating will not be permitted.

1020.2 Procedure