CONCRETE PIPE & SPECIAL SECTIONS
Acceptance of concrete pipe and related precast units shall be on the basis of certification, plant approval (load-bearing tests), strength properties, absorption and permeability properties, material tests and inspection of manufactured pipe for visual defect and imperfections.
Concrete pipe and related precast units shall conform to the applicable requirements of AASHTO M86 (M86M), M170 (M170M), M198, M206 or M207 (M207M) for the strength (class) and size specified and the additional requirements as set forth in Section 4145, Section 4149, Section 2419, and other sections of the Standard Specifications of the Iowa Department of Transportation. Each project shall include the same wall thickness for each pipe size. Acceptance of standard strength 1500D through 3750D (75D through 175D) (class II through class V) concrete pipe, special sections and related precast units will be on the basis of certification for each strength (class) and size from approved producers subject to periodic plant inspections and testing of monitor samples. Producers approved to furnish pipe, special sections and related precast units on the basis of certification are listed in Appendix A and Appendix B of IM 445.01. Monitor inspection and testing will be performed by the Iowa Department of Transportation.
The reinforcement connectors and all the steel and iron products and coatings that will be incorporated in the final product shall be of a domestic origin and shall be melted and manufactured in the USA.
The connectors near the top of the pipe sections and all other fasteners shall be coated using electroplating in accordance with ASTM B633, service condition SC4, required coating thickness of 0.5 mil. Classification and coating suffix FE / ZN 12. The connectors shall meet the requirements of ASTM A36 steel. All joints shall be watertight (when specified) and shall be wrapped with engineering fabric, from an approved source listed in IM 496.01 Appendix A. Rubber gaskets for sealing the joints (when specified) shall meet the requirements of ASTM C443 or ASTM C443M.
In addition to the marking requirements of Section 4145 of the Standard Specifications, a Quality Control Technician shall legibly mark the word “certified” on each unit. Each unit of pipe, including special sections so marked and stamped, identifies the pipe as being in compliance with the applicable AASHTO or ASTM Specifications, and the Iowa Department of Transportation Standard Specifications. NOTE: 18” pipe or smaller may be identified only on the outside surface. All other sizes shall be identified both on the outside and inside surfaces.
All pipes shall have the following markings: strength or class, date manufactured, size, and trademark. Waterproof paint or ink shall be required. The District Materials Engineer shall approve any other methods.
WET CAST
A. Air content (when concrete requires air entraining)-one test per week of production
B. Concrete strength-6 cylinders per mix, per week
C. Test at 7 days (3 cylinders) and at 28 days (3 cylinders)
D. Compressive strength requirements:
1. 1500D (75D) (Class II) Reinforced Concrete Pipe
12-inch to 72-inch diameter pipe, 4000 psi
78-inch to 144-inch diameter pipe, 5000 psi
2. For 2000D (100D) (Class III) Reinforced Concrete Pipe
12-inch to 72-inch diameter pipe, 4000 psi
78-inch to 144-inch diameter pipe, 5000 psi
3. 3000D (150D) (Class IV) Reinforced Concrete Pipe
12-inch to 144-inch diameter Pipe, 5000 psi
4. 3750D (175D) (Class V) Reinforced Concrete Pipe
12-inch to 144-inch diameter pipe, 6000 psi
E. Minimum strength requirements for all related precast units shall be as follows:
28-day strength: 4000 psi
Shipping strength: 3500 psi
Moving Strength: 1500 psi
Concrete Pipe Absorption Test - two tests per calendar year
Concrete Strength - six tests per calendar year
The minimum testing rate required shall be two pipes per size, per strength (class), per year. The District Materials Engineer (DME) shall be notified prior to testing or a schedule may be mutually agreed upon.
All pipe and related precast items suitable for certification shall be stamped “certified” prior to or at the time of stockpiling. Certified pipe that no longer meets specifications (rejected) shall have the certification identification obliterated.
The producer shall afford the State of Iowa the opportunity for inspection, and notify the District Materials Engineer of the intended production schedule.
The producer shall test concrete pipes in accordance with the requirements of AASHTO T280 or ASTM C497. Tests results shall comply with the strength and absorption requirements contained therein. District Materials Engineers may observe and monitor the testing and determine the testing frequency. The producer shall supply a copy of all test results and a copy of the report of each annual inspection trip to the Office of Materials and the District Materials Engineer.
GENERAL REQUIREMENTS
A. Winter concrete placement requires the approval of the DME, based on the following:
1. Approved procedures for cold weather
2. Applicable requirements of Article 2403.11
3. Plant approval (Local Batching and/or ready mix)
B. Construction of reinforced gauges shall be in accordance with the requirements of Article 4145.06C of the Standard Specifications.
C. Forms shall be smooth and true to shape and exact dimensions and maintained in good condition.
D. Concrete shall be thoroughly consolidated by means of using external or internal vibrators.
E. Lift holes may be allowed when requested by contractor.
1. Maximum two lift holes per pipe
2. Lift holes shall not be larger than 2½ inches in diameter
3. The circumferential reinforcement of a single cage pipe shall not be cut at the lift hole locations
4. The outer cage of a double cage reinforced pipe may be cut at the lift hole locations
5. Circumferential reinforcement may be allowed (when practical) to be slightly bent to allow for the lift holes.
6. A polyethylene, low-density plug may be allowed to be used to cover the lift holes prior to backfill.
a. The Iowa DOT has approved the following: Trade Name - Popit, Manufacturer’s Name – Popit, Inc., Levittown, PA 19057.
Pipes and related precast units may be repaired due to imperfections in manufacturing or minor damage during handling if the repaired pipe and related units are acceptable to the DME and if the repair conforms to the requirements of the specifications.
Pipes and related precast units shall be subject to rejection upon the following conditions:
A. Pipes/units are not being inspected and/or certified
B. Pipes/units fail to conform to any of the specification requirements
C. Poor workmanship and imperfections