BBV Attenuation Tank Pre-Cast

The scope of work includes design and supply of a precast Attenuation Tank for Duddeston Mill Road North, Birmingham. The tank will be made from precast concrete elements and will have an overall internal length of 31m and an internal width of 8.35m with a clear height of 1.70m. The structure will consist of a two-span box structure. A minimum of 2 no. access points to the tank are proposed close to the inlet and outlet locations, 750x750mm openings . The whole attenuation tank will be a fully precast concrete structure. The tank segments are fully integral twin-cell box structures without joints. Precast tank units shall be joined longitudinally by a concrete spigot and socket joint. Minimum design working life for each element The precast concrete elements of the tanks should have a design working life of not less than 120 years (Category 5). Concrete cover has been specified to achieve this lifespan. Other sub-elements will have the following design working lives: • Waterproofing: 30 years. • Sealants to joints of precast units: 20 years to first maintenance. General notes - Design, supply and delivery only - Future waterproofing proofing rebate to be proposed and agreed at design stage - Lifting points to be included in the design - Anticipate delivery of units with bituminous waterproofing system applied - Integrated joint waterproofing with compressible strip and - Assumptions and exclusions to be included