GENERAL

Provisions of this IM shall apply to the production and fabrication of concrete pipe and special sections by approved producers in accord with IM 445. Approved producers and fabricators are listed in the Materials Approved Products Listing Enterprise (MAPLE).

Concrete pipe and related precast units shall conform to the applicable requirements of AASHTO M86, M170, M206 or M207.

GENERAL REQUIREMENTS

Each pipe size furnished to a project shall be of the same wall thickness.

WET CAST PRODUCTION

Air content (when concrete requires air entraining)-one test per week of production
Concrete strength-6 cylinders per mix, per week
Test at 7 days (3 cylinders) and at 28 days (3 cylinders)
Compressive strength requirements:

1. 1500D (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 (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 (Class IV) Reinforced Concrete Pipe

12-inch to 144-inch diameter Pipe, 5000 psi

4. 3750D (Class V) Reinforced Concrete Pipe

12-inch to 144-inch diameter pipe, 6000 psi

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

DRY CAST PRODUCTION

Concrete Pipe Absorption Test - two tests per calendar year

THREE-EDGE BEARING TESTS

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.

The producer shall test concrete pipes in accordance with the requirements of Section 4145 of the Standard Specifications. 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.

LIFTING HOLES

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.

The Iowa DOT has approved the following: Trade Name - Popit, Manufacturer’s Name – Popit, Inc., Levittown, PA 19057.

PIPE CONNECTORS

The pipe connectors shall meet the requirements of Section 2416 of the Standard Specifications and Standard Road plan DR 121. All the steel and iron products and coatings shall meet the requirements of IM 107.

WATERTIGHT JOINTS

All joints shall be watertight (when specified), shall meet the requirements of 4149 of the Standard Specifications.

REPAIRS

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.

IDENTIFICATION

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

ACCEPTANCE

Acceptance of concrete pipe and related precast units shall be on the basis of certification by approved plants. Certification will be based on ~~plant approval~~ (load-bearing tests), strength properties, absorption and permeability properties, material tests and inspection of manufactured pipe for visual defect and imperfections.

REJECTION

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