S&B Herba Foods have been millers and processors in the UK since 1919 (as Joseph Heaps), today they are a division of Spanish food giant Ebro Pulevo, the worlds largest rice company, with UK milling and processing facilities located at Fulbourn near Cambridge and in Liverpool.
At both sites there are huge reinforced concrete silos for their grain storage and in 2006 the silo refurbishment specialists, Folcrete Restoration Services Limited completed a major external refurbishment of the Fulbourn silos, using a complete concrete repair and protection system from Remmers (UK) Limited.
Following the success of this project and the good working relationships established, the same combination of Folcrete specialists using Remmers materials was selected in 2007 to carry out a similar refurbishment of the raw materials grain storage silos at the Liverpool facility.
Following the latest European Standard EN1504, Folcrete first carried out a comprehensive Condition Survey of the structure, to identify the type and extent of the damage. This confirmed that the main problem was spalling concrete over corroding steel reinforcement, which had lost the protection of the alkalinity in the surface concrete, due to progressive atmospheric carbonation.
This had then been aggravated by chlorides from the exposed marine atmosphere of the site, but due to the good quality of the original precast concrete units from the 1950’s construction, this was only superficial and of no structural significance.
As these large silo structures are more than 23m high, access for the works was provided by Folcrete’s own Powered Access Cradles.
At the start of the works, all of the concrete surfaces were thoroughly cleaned, using high pressure water jetting and any steel reinforcement that was exposed, was grit blasted to clean metal. The damage and defects in the surface were then repaired with Remmers polymer modified mortars, which are ideal for this type of work because they can be feather edged into the repairs, reducing the need for any further expensive angle cutting and preventing the removal of sound concrete.
The whole of the cleaned and repaired silo surface was then coated with Remmers Elastoflex coating system, an advanced acrylic resin based material that provides long term crack bridging protection, prevents any further carbonation of the concrete and stops the ingress of damaging water borne chlorides.
The Liverpool project has now also been completed to the full satisfaction of the client S&B Herba Foods, and their Consulting Engineers K F Shadbolt and Partners of Gateshead.
