Concrete Pressure Pipe and Fittings

Pipe

Pipe manufactured in accordance with the ANSI/AWWA C300,3 C301,4 and C3025 standards is required to have high-strength structural concrete on the inside surfaces of the pipe which, in addition to enhancing the load-carrying capability, provides corrosion protection to the embedded reinforcing elements. All concrete is placed at the factory by vertical casting, centrifugal casting, or radial compaction methods.

Pipe manufactured in accordance with the ANSI/AWWA C3036 standard is required to have a mortar protective lining. The mortar is mixed using 1 part portland cement to 3 parts fine aggregate, with enough water added to obtain the necessary workability. The mortar lining is placed at the factory by the centrifugal

casting method.

Fittings

The fabricated steel fittings for all four types of concrete pressure pipe (ANSI/AWWA C300,3 C301,4 C302,5 and C3036) receive a mortar lining. The mortar is mixed using 1 part portland cement to 3 parts fine aggregate, with enough water added to obtain the necessary workability. These mortar linings are placed at the factory by hand layup, pneumatic placement, or centrifugal casting methods. 

Application methods and curing

Table A summarizes the lining application and curing methods allowed by the various concrete pressure pipe standards. This table also shows the limits on the ambient temperature and the mortar or concrete mix temperature during application of the lining.

Table A: Concrete Core and Mortar Lining Application and Curing Methods for Concrete Pressure Pipe

		ANSI/AWWA C300	ANSI/AWWA C301	ANSI/AWWA C302	ANSI/AWWA C303
Pipe	Application	Vertical casting or radial com- paction, con- crete mix tem- perature must be between 40°F (4°C) and 90°F (32°C)	Centrifugal cast- ing, vertical casting, or ra- dial compac- tion, concrete mix tempera- ture must be between 40°F (4°C) and 90°F (32°C)	Vertical casting or radial com- paction, con- crete mix tem- perature must be between 40°F (4°C) and 90°F (32°C)	Centrifugal cast- ing, concrete mix tempera- ture must be over 40°F (4°C)
	Curing	Accelerated method with steam for 12 hrs minimum, or with water for 12 hrs minimum	Accelerated method with steam for 12 hrs minimum, or with water for 12 hrs minimum	Accelerated method with steam for 12 hrs minimum, or with water for 12 hrs minimum	Accelerated method with steam for 6 hrs minimum, or with water for 24 hrs minimum
Fittings	Application	Hand-placed or pneumatic placement	Hand-placed or pneumatic placement	Hand-placed or pneumatic placement	Centrifugal cast- ing, hand- placed, or pneumatic placement
	Curing	Accelerated method with steam for 12 hrs minimum, with water for 12 hrs mini- mum, or cur- ing com- pound per ASTM C309	Accelerated method with steam for 12 hrs minimum, with water for 24 hrs mini- mum, or cur- ing com- pound per ASTM C309	Accelerated method with steam for 12 hrs minimum, with water for 12 hrs mini- mum, or cur- ing com- pound per ASTM C309	Accelerated method with steam for 6 hrs minimum, with water for 24 hrs mini- mum, or cur- ing com- pound per ASTM C309

Thickness

The thickness of the concrete or mortar linings for concrete pressure pipe vary by pipe diameter and pipe type but are at least 0.50 in (13 mm) thick. In the case of the AWWA C300, C301, and C302 pipe, the concrete core, in addition to providing corrosion protection to the steel cylinder or reinforcing mesh, provides resistance to external loads. This is why the thickness can vary with the design parameters.

The mortar lining in the AWWA C303 type of pipe is primarily used to provide corrosion protection to the steel cylinder. Its thickness does not generally change with the design parameters. The mortar lining for fittings of all concrete pressure pipe types must be at least 0.375 in (9 mm) thick. The primary purpose of the

mortar lining in fittings is to provide corrosion protection.

Joint Protection

As shown in Fig. A, a small annular gap between the lining of adjoining pipe sections results after assembly of a concrete pressure pipe steel bell and spigot joint in the field. 

Mortaring of interior joint recess for pre-stressed concrete cylinder pipe

Depending on the nature of the water being transported and the protective coating applied to the joint rings by the pipe manufacturer, it may be necessary for the installing contractor to mortar this annular recess to protect the steel joint rings. The transmission of aggressive water such as raw sewage or seawater usually requires that the inside joint recess be filled with cement mortar after installation.

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