Precast concrete manholes are an integral component of any modern sewer system. A properly designed and installed precast concrete manhole system provides superior watertight performance compared with competing methods and materials. A typical precast concrete manhole could be installed 500 feet deep and more because lateral forces act equally around the periphery, which places the section in pure compression- the ideal state for concrete. Manufactured in the controlled environment of a plant, these vital infrastructure components will stand strong for decades of trouble-free service.
Precast concrete strengthens with time, while other materials can deteriorate, experience creep and stress relaxation, lose strength and/or deflect over time. The load-carrying capacity of precast concrete manhole is derived from its own structural qualities and does not rely on the strength or quality of the surrounding backfill materials. Studies have shown that precast manhole is of M-40 Grade and having AA Class Loading Capacity.
Precast Manholes are easy to install. Precast Manholes can be easily installed on demand and immediately backfilled- there is no need to wait for concrete or mortar to cure at the job site. The degree of soil compaction around the manhole chamber and remaining trenches is never a problem, making installation easier. Most contractors are familiar with how to handle precast concrete manholes and can install them with a small crew and crane.
REDUCED WEATHER DEPENDENCY
Precast Manhole increases efficiency because weather will not delay production of the manholes. In addition, weather conditions at the job site do not significantly affect the schedule because less time is required to install precast manhole compared with other construction materials, such as case-in-place concrete or brick.
Precast Circular Manholes are used in sanitary sewer and storm drain systems for access, observation and junctions. They are good choice for:
- Pump Stations
- Well Wells
- Storm Water Management Structures
- Impoundment Overflow Structures
All manholes and vertical structures can be provided for highway, railroad and aviation loading.
- Access to the System for Maintenance
- Observation Points
- Changes in Pipe Size
- Changes in Pipe Shape
- Changes in Direction of Pipe
- Junctions for Multiple Pipes
Precast Manholes and Extension Rings are available in Three Sizes, Details given below:
|S. No.||Size of Manhole||Height of Manhole||Height of Extension Risers|
|1.||1000 MM||800 MM||1 & 2 Running Feet|
|2.||1200 MM||1000 MM||1, 2 & 3 Running Feet|
|3.||1500 MM||1300 MM||1, 2 & 4 Running Feet|
Precast Manholes and Risers are manufactured as per the drawings and specifications of Jaipur Development Authority and RUIDP.