Category:1024 Corrugated Aluminum Alloy Culvert Pipe and Corrugated Aluminum Alloy Structural Plate
From Engineering Policy Guide
|Approved and Pre-Qualified List|
|Aluminum Alloy Sheet Manufacturers|
|Current General Services Specifications (MGS) By Subject|
This article establishes procedures for the inspection of corrugated aluminum alloy sheets intended for use in culvert pipe and the inspection of fabricated aluminum alloy pipe. Refer to Sec 1024 for MoDOT’s specifications.
For Laboratory testing and sample reporting procedures, refer to EPG 1024.4 Laboratory Testing Guidelines for Sec 1024.
(a) Micrometer or vernier caliper capable of measuring to 0.0001 in. (0.00254 mm) and accurate to within at least 0.001 in (0.0254 mm).
(b) Rule with suitable graduations to accurately measure the material to be inspected.
(c) Balance or scale accurate to within 0.5 percent of the weight (mass) of the sample to be weighed.
(e) Applicable AASHTO specifications.
1024.2.1 Corrugated Aluminum Culvert Pipe
Corrugated aluminum culvert pipe and pipearches 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.
1024.2.1.1 Manufacturer Approval
Prior to acceptance of corrugated aluminum culvert pipe, 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 EPG 106.1 Source of Supply and Quality Requirements.
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, and county, date of inspection, quantity (ft or m), pipe diameter.
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.
1024.2.1.2 Sheet Manufacturer's Certified Analysis and Guarantee
Prior to the acceptance of corrugated aluminum for culvert pipe and pipe-arches, 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 EPG 106.1 Source of Supply and Quality Requirements.
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.
1024.2.2.1 Aluminum Sheet
The aluminum sheet used for fabrication shall be in accordance with AASHTO M 197 or AASHTO M 219. The aluminum sheet may be furnished flat in coils or cut lengths or corrugated in cut lengths. Furnished aluminum shall be free from injurious defects such as blisters and flux.
1024.2.2.1.1 Chemical Composition
The base metal composition of the aluminum sheet shall comply with the requirements AASHTO M 197 or AASHTO M 219.
1024.2.2.1.2 Mechanical Properties
The aluminum when tested in the longitudinal direction of aluminum sheets prior to corrugation or other fabrication shall comply with the requirements of AASHTO M 197 or AASHTO M 219. Aluminum sheet tested after corrugating or other fabrication shall conform to the tensile and yield strength requirements of AASHTO M 197 or AASHTO M 219 but the elongation will not be required.
Sheet thickness shall conform to the tolerances specified in AASHTO M 196 or AASHTO M 219.
The dimensions of the corrugations shall be in accordance with AASHTO M 196 or AASHTO M 219. Corrugations shall form smooth continuous curves and tangents.
Covering width of corrugated cut lengths shall be in accordance with AASHTO M 196 or AASHTO M 219. 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.
1024.2.2.1.6 Edge Lip
Lip dimensions of corrugated cut lengths shall be in accordance with AASHTO M 196 or AASHTO M 219. The lip dimension is measured along the radial curvature from the crest of the outermost corrugation to the edge of the sheet.
The rivets used in riveted fabrication shall be as outlined by AASHTO M 197 or AASHTO M 219. They shall be thoroughly galvanized and sherardized.
1024.2.2.3 Bolts and Nuts
Bolts, nuts, and other threaded articles used with coupling bands and other hardware items used with coupling bands, shall be coated by one of the processes specified in AASHTO M 196 or AASHTO M 219.
1024.2.3 Identification Markings for Aluminum Sheet
Each sheet or coil of aluminum is to be clearly marked, in accordance with AASHTO M 197 or AASHTO M 219, 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, AASHTO designation number of the aluminum and identification symbols showing heat number and 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 EPG 106.1 Source of Supply and Quality Requirements are to be accepted.
1024.2.4 Random Sampling of Aluminum Sheet
Random samples are to be submitted to the Laboratory for determination of 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 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 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 EPG 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 aluminum 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.
1024.2.5 Field Inspection
Field inspection shall be performed using the 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.
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.
1024.2.5.1 Mill and Factory Inspection
The engineer may have the sheet aluminum 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 aluminum 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 aluminum pipe or end sections are to be marked as described in Sec 1020.7. The brand of base metal is to be checked to verify that it is listed on EPG 106.1 Source of Supply and Quality Requirements. 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 thickness, 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 AASHTO M 196 or AASHTO M 218.
The specified inside diameter, in accordance with AASHTO M 196 or AASHTO M 218, shall not vary more than 1 percent or 0.5 in. (13 mm), which ever is greater 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 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.
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 “MoDOT OK” stamp should not be used.
If pipe is rejected for not being in accordance with specifications and the requirements set forth in the 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.
Pipe shall be a full circle or pipe arch. 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.
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.
1024.2.6.3 Riveted Seams
Riveted longitudinal seams shall be staggered to the extent that no more than three thicknesses of aluminum 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.
1024.2.6.4 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 aluminum 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 aluminum 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 rerolled to form annular corrugations, the lock seam in the rerolled end shall not contain any visible cracks in the base metal.
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.
1024.2.6.5 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 "Outside End-Round".
1024.2.6.6 End Finish
Rolled or otherwise reinforced ends will not be required for pipe or pipe-arches.
The ends of individual lengths of pipe with helical corrugations may be rerolled to form annular corrugations extending at least two corrugations from the pipe end.
1024.2.7 Workmanship and Finish
In addition to the requirements of fabrication, the completed pipe, shall show careful, finished workmanship in all particulars. Any item on that shows defective workmanship will be rejected. This requirement applies not only to the individual item but also 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 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) Lack of rigidity.
(d) Illegible markings.
(e) Ragged or diagonal sheared edges or ends.
(f) Uneven laps in riveted or spot welded pipe.
(g) Poorly formed rivet heads.
(h) Loose, unevenly lined or unevenly spaced rivets or spot welds.
(i) Defective spot welds or continuous welds.
(j) Dents or bends in the metal.
(k) Loosely or poorly formed lockseams.
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 will not be permitted.
1024.3 Sample Record
The manufacturer is required to notify MoDOT of impending shipments by contacting Materials in the district responsible for their plant and providing the information required by the Pipe Shipping Report Form for reporting to a district office, GS-17 Form 2. Construction and Materials will be notified by shippers (see Pipe Shipping Report Form for reporting to the Central Office, GS-17 Form 1) that are out-of-state and are not routinely visited by district Materials. This information will allow MoDOT to track the material, obtain samples, and perform Quality Assurance inspection as necessary.
A SiteManager sample record shall be created for each size of pipe in each shipment.
Each SiteManager sample record will be created by the District responsible for the manufacturer. Construction and Materials will create sample records for pipe shipped by out-of-state manufacturers.
SiteManager shall be used when submitting samples to the Laboratory. The inspector is to show the following information for each lot sampled:
(a) Complete identification shown on the sheet or coil.
(b) Sampling pattern used.
(c) Results of field sheet thickness measurements (minimum and average) for each lot sampled.
(d) Whether corrugation dimensions comply with specification requirements.
Field inspection reports of fabricated pipe and pipe-arches shall be made using SiteManager and should include the size of corrugation and type of fabrication (riveted, spot welded, helical lock seam, or helical welded seam). Pipe quantity shall be shown in feet. The sample record is to indicate acceptance or rejection. If the sample record indicates rejection, the reason for rejection shall be stated in the remarks or the test result details of the sample record. If the sample record indicates acceptance, the basis of acceptance of the metal shall be on results of Laboratory tests or the approved brand and an examination of the material, and because fabrication is satisfactory.
Random spot-checking for thickness, visual examination of helical lock seams or weld seams, and tension testing of lock seams performed by the manufacturer, is to be recorded in the inspector's diary and need not be recorded on the inspection report.
1024.4 Laboratory Testing Guidelines for Sec 1024
This article establishes procedures for Laboratory testing and reporting samples of corrugated aluminum alloy culvert metal.
Tensile strength, yield strength, and elongation tests shall be conducted according to ASTM B209. When requested, thickness shall be determined with a micrometer graduated in increments of 0.0001 in. (.00254 mm) and reported to 0.001 in. (.0254 mm). At least five thickness measurements are to be made on the tangents of corrugations at least 3/8 in. (9.5 mm) from the edge of metal. Test results and calculations shall be recorded through SiteManager.
1024.4.2 Sample Record
The sample record shall be completed in SiteManager, as described in Sample Record General Information , and shall indicate acceptance, qualified acceptance, or rejection. Appropriate remarks, as described in EPG 106.20 Reporting, are to be included in the remarks to clarify conditions of acceptance or rejection. Test results shall be reported on the appropriate templates under the Tests tab.