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JOINTS Introduction Joint configurations include bell and spigot, tongue and groove and modified tongue and groove. Joint gaskets and sealants fall into the general categories of cement mortar or mastic sealants, rubber gaskets, external sealing bands, steel end rings and butyl or bitumen rope. Although the primary considerations in joint quality are permissible infiltration and exfiltration rates, other important performance requirements are: resistance to infiltration of backfill material, control of leakage due to internal or external pressure, flexibility to accommodate lateral deflection of longitudinal movement, pipeline continuity and smooth flow line, infiltration of groundwater for subsurface drainage and ease of installation. Cement Mortar and Mastic Compound Circular pipe, special shapes and boxes are available with tongue and groove joints that may be packed with cement mortar, filled with a preformed butyl or bitumen gasket sealing compound or a trowel applied mastic compound. Such joints have a successful experience record and are generally used for storm sewer construction. Properly applied mastic joint fillers provide flexibility and help to keep fines out of the pipe. ASTM C 443 Joints for Circular Concrete Sewer and Culvert Pipe, Using Rubber Gaskets Joints recommended for circular sewers where infiltration or exfiltration is a factor in design are the following flexible watertight joints using compression type rubber gaskets for sealing the joints. C 443 joints are intended for use with pipe manufactured to meet the requirements of ASTM C 76 and may be used with either bell and spigot or tongue and groove pipe. The joint is made up of concrete surfaces, with a compression type rubber gasket. O-ring type joints will also meet the performance requirements of C 443. ASTM C 361 Reinforced Concrete Low-Head Pressure Pipe Although ASTM C 361 covers both low-head pressure pipe and the joint requirements for this type of pipe, it is referenced here for special conditions of internal or external head. C 361 joints can be supplied for use with pipe manufactured to meet the requirements of ASTM C 76. The joint is made up of concrete surfaces with a groove on the spigot for an O-ring rubber gasket (also referred to as a confined O-ring type joint). Provisions are made in Section 8 for an alternative joint as approved by the owner. These joints are normally used in gravity sewers where exceptional tightness is required. This type of joint meets all the joint requirements of ASTM C 443. Steel end rings may also be used for the special condition of pressure flow. ASTM C 877 External Sealing Bands for Non-Circular Concrete Sewer, Storm Drain, and Culvert Pipe For special conditions where an effective rubber seal is desired for jointing non-circular concrete pipe (arch, elliptical and box shapes), an external sealing band is available meeting the requirements of ASTM C 877. These sealing bands are generally limited to non-circular pipe with tongue and groove configurations. ASTM C 877 describes specific types of external sealing bands. Other types of sealing bands with adequate results may also be specified. ASTM C 990 Joints for Concrete Pipe, Manholes, and Precast Box Sections Using Preformed Flexible Joint Sealants C 990 joints are
intended for use with circular pipe, elliptical pipe or precast box
sections and may be used with either bell and spigot or tongue and
groove pipe. The joint is made up of concrete surfaces, with a
preformed bitumen or butyl rubber sealant and is also referred to as
bitumen or butyl rubber rope. |Home| |About ICPA| |Meet Our Staff| |Join ICPA|
Illinois
Concrete Pipe Association |
