Ashford Crescent Flood Alleviation Scheme, Preston
Client: United Utilities
Project: Ashford Crescent Flood Alleviation Scheme, Preston
Contractor: Balfour Beatty Utilities/Tunnelling
Product: GM3 supplied in a Tarmac Mortar silo with M-Tec D50 mixer
Project brief:
Balfour Beatty Utilities were appointed to construct a series of
surface water drainage ducts and a collection tank. The collection
tank was a 20m diameter, 14m deep vertical shaft constructed from
precast concrete segments. Once in place the concrete segments
are surrounded by grout, this fills and seals any voids. The amount
of grout required varies with ground in which the segments are
being placed.
The solution:
Grout is typically supplied in 25kg paper bags which are ripped and tipped into a mixer above ground, the flowing grout is then pumped to the required location. Balfour Beatty recognised that they could improve their site operation by the use of a Tarmac silo.
The silo supplied was one that has been extensively developed and supported by Tarmac's mortar business. The requirements for each silo is a level 3x3x0.125m C35 reinforced concrete base, a single phase type C or D power supply and a mains water connection via a 25mm diameter pipe or equivalent. Training with regard to operation, cleaning, safety and maintenance was delivered from a Dry Silo expert as part of the installation.
The benefits:
The dry grout is stored in a silo which offers greater protection on a construction site
and takes a smaller footprint than palletised 25kg bags.
The silo is delivered with a purpose designed mixer (no extra mixer hire necessary).
Push button control of the supply of grout - simply starting and stopping the mixer.
The consistency of the mix can be varied almost instantaneously at the silo
by turning a tap controlling the water supply.
The manual handling task of ripping and tipping bags is removed - reducing both the
health and safety risk and the labour requirement.
The mixing operation of dry powders takes place at the factory under controlled conditions
and prior to water addition in the silo mixer which is effectively sealed, both aspects of the
system reduce the risk of dust emission to the environment.
Site waste is reduced via:
- No requirement to dispose of packaging/pallets.
- Touch button control on the continuous mixer means that the precise amount of grout required is mixed.
Silo is delivered with product ready for production.
Further bulk deliveries are made to site using a conventional powder tanker, capable of
delivering 26 tonnes. The unloading is via compressed air transfer and does not require
a lifting operation on site.
Please contact us for more information.




