ANSI AWWA C205-00 pdf free download – CEMENT-MORTAR PROTECTIVE LINING AND COATING FOR STEEL WATER PIPE- 4 IN. (100 mm) AND I ARGER- SHOP APPLIED
4.4.6.1 General. All defects, including, but not restricted to, sand pockets, voids, oversanded areas, blisters, and cracking as a result of impacts, shall be cut out and replaced by hand or pneumatic placement to the same thickness as required for the cement- -mortar lining.
4.4.6.2 Lining cracks. Temperature and shrinkage cracks in the cement- mortar lining less than 1/16 in. (1.6 mm) in width need not be repaired. Cracks wider than 1/16 in. (1.6 mm) need not be repaired if it can be demonstrated to the satisfaction of the purchaser tbat the cracks will heal autogenously under continuous soaking in water. The autogenous healing process may be demonstrated by any procedure that keeps the lining of the pipe continually wet or moist. Pipe used in the demonstration shall be representative of the pipe to be supplied, and water for the moistening of the pipe shall be chemically similar the water to be carried in the pipeline.
4.4.7.1 General. Immediately after completion of spinning, the pipe sections may be moved to a curing area. Care shall be exercised at all times to prevent damage to the lining. At the option of the manufacturer, linings shall be accelerated cured, moist cured, or cured by a combination of accelerated and moist curing. Accelerated curing or moist curing may be used interchangeably on a time-ratio basis of5 /3 hr of moist curing to 1 hr of accelerated curing. In any case, the total curing period shall be equivalent to 96 hr of moist cure and the minimum curing period before applying the exterior coating shall be equivalent to 24 hr of moist cure. The lining shall be kept continually moist until completion of the minimum specified curing period.
4.4.7.2 Moist curing. Moist curing may be used only if the minimum ambient temperature exceeds 40°F (4°C) continuously during the required minimum curing period. No credit shall be allowed for any time during which the temperature drops below 50°F (10°C).
4.4.7.2.1 On arrival at the curing area, but not later than 30 min after completion of the lining operation, pipe ends shall be covered with plastic or wet burlap for a minimum moist-curing period of 24 hr before applying the exterior coating, if this coating is specified. If a cement -mortar exterior coating is not specifed, the lining shall be moist cured for 96 hr before shipment. The ends of the pipe sections shall be kept closed with plastic end caps during the curing period, except when sprinkling heads are used, the reinforcement and outside coatings are being applied, or accelerated curing is being substituted. If the plastic end caps are installed at that time, they can be used for shipping to the jobsite as indicated in Sec.6.2. The manufacturer shall exercise care and diligence to avoid drying out or cracking of the lining.
4.4.7.3 Accelerated curing. On arrival at the curing area, but not later than 30 min after completion of the lining operation, accelerated curing may begin. The temperature of the pipe shall not be raised above 95°F (35°C) by the introduction of heat for 4 hr after final placement or until the cement mortar has taken its initial set, whichever occurs first.