Welcome to the Summer 2015 issue of Pipelines
The popularity of precast manhole base systems is rising as users appreciate the many benefits they offer. However, there are still many installers, developers, specifiers and clients missing out.
If you are interested in reducing risk on site, cutting installation time and costs, improving quality and eliminating leakage and you are not using CPSA members’ precast manhole base systems, it’s time you took a closer look…
Stuart Crisp, Director, CPSA
Concrete manhole system, packed with many benefits that will satisfy designers, contractors and operators alike
Traditionally, manhole construction has required the base to be formed in-situ where building of the channel, connections and benching occurs in the trench, often in confined spaces that can present a safety hazard for operatives frequently encountering wet and unpleasant conditions.
The process can take around 40 hours per manhole to complete and is not always successful, particularly in terms of water-tightness, where egress of waste water can lead to contaminated groundwater and where ingress can contribute to overloaded sewer networks plus increased energy usage, carbon emissions and running costs at treatment works and pumping stations.
These issues can be avoided by using the new circular precast concrete manhole base systems available from all CPSA members. They comprise a circular precast concrete base unit, complete with channel and benching with predetermined / bespoke combinations of inlet(s) and outlet and new chamber rings with watertight flexible joints and no lifting holes, thereby removing points of possible leakage.
Base units and chamber rings are made with thicker, stronger walls. The robust design means that the requirement for a concrete surround is eliminated in most cases, considerably reducing the total volume of concrete required and resulting in up to 43% lower(*) embodied carbon for the installation. The excavation is backfilled sooner and there is less need for men to work in confined spaces. This reduces time spent in the excavation, further improving site safety and reducing installation time and costs.
The manhole system the drainage industry has been waiting for
Precast Concrete Manhole Installation
Installation of the whole system is speedy and efficient. Take a look at CPSA members’ demonstration videos
Less concrete is used, there is less waste and less excavated material disposed to landfill. An estimated UK annual saving of over 22,000 tonnes of CO2e could be achieved if all traditional manhole components manufactured by members of CPSA changed to the new precast base system.
All systems are manufactured under factory conditions by third party certified companies to ISO 9001 quality management system. Products are Kitemarked to BS EN 1917:2002 and BS 5911-3 and tested under laboratory conditions.