FAQs

Precast Concrete Bunker Walls 

 

Q: What does prestressed mean?

A:  The steel reinforcing is tensioned before pouring the concrete into the mould. Click this link for more information on prestressing.

Q: How do we off load the panels?

A: The panels will require off loading with a forklift, telehandler or a crane. 

Q: When the panels are off loaded how do I store them?

A: The panels should be stacked on firm, level ground and separated using the stacking timbers provided. These should be placed on the panels in accordance with the stacking drawing  that should be provided to you when you place your first order with us. 

Q: How do the panels fix?

A: In the case of horizontal panels spanning between building columns the panels can be fixed onto the front of the columns using the clips and bolts provided. The panels come with 4 nos cast-in fixing points (threaded sockets) in the outside face. A steel plate clips behind the flange of the column and is bolted into the fixing point (Fixing Detail Drawing).
     In the case of vertical cantilever panels the bottom of the panel (usually 400mm) is cast into a supporting foundation. The panels are propped in a vertical position on cradles and reinforcing bars pass through the panels which tie them into the foundation concrete. No above ground steelwork is required. (Vertical Layout Drawing)  
 

Q: Can horizontal panels be fitted between the column webs?

A: Yes, either the panels can be fitted towards the outside of the building using the clips as above or pushed up towards the inside of the building and fixed in place with angle steels bolted/welded in the gap.

Q: What size panels do I need?

A: If fitting to the front face normally 8-12mm is deducted from the overall c/c measurement to allow for manufacturing tolerance. If the panels are fitting between the webs of the columns we need to deduct enough to allow you to push the panel in at one end, swing it into line and walk it back to give sufficient bearing at both ends, the exact amount to be deducted depends on the size of the columns to be used. If you provide this information or a GA drawing to our office we will calculate this for you.
 

Q: What length do you make the panels?

A: We manufacture panels to any length required (subject to limits on handling/weight etc).
 

Q: Do you charge more for non-standard panel lengths?

A: No, prices are calculated based on overall square metres required plus haulage.  

Q: What do the horizontal panels sit on, do they need a foundation?

A: The panels do not require a foundation, they either sit on the floor of the building or on landing cleats bolted/welded to the supporting columns.  

Q: How big do the landing cleats need to be?

A: A landing cleat is usually a short length of angle steel bolted/welded to the stanchion. The panel needs a square seating area equivalent to its thickness, ie 95mm thick panels require 100mm x 100mm at both ends, 145mm thick panels require 150mm x 150mm , 180mm thick panels require 180mm x 180mm. However you need to remember to allow a little extra for the gap between the panels and It is also important that the landing cleats are level.

Q: If the panels sit on the floor of the building how can we make it watertight?

A: We can supply (at additional cost) a compressible sealant to go under the bottom panels which will take up any minor variations in the floor and provide a watertight seal.
 

Q: How do we lift the panels?

A: The simple method is using two large ‘D’ shackles, which fix through two holes cast into the panel, linked together with a lifting chain. The holes will need to be grouted up after the panels are erected. Alternatively we can cast in a proprietary lifting insert into the top edge of the panel and supply you with special lifting clutches to fit these. This system has the advantage that there are no holes in the panels but it is slightly more expensive. 

Q: How is the sealant to be used?

A: The sealant we supply is to be applied to all the joints after the panels have been erected using the applicator gun provided (if ordered). Vertical joints should be filled with expanding foam (not supplied) which should then be cut back to give a shallow joint to which the mastic can then be applied.  

Q: How can I get a professional finish when applying the mastic sealant?

A: To give a professional appearance it is advisable to use masking tape along either side of the joints which can be peeled off afterwards to give a neat edge.
 

Q: How much sealant do you provide?

A: We expect a 600ml tube of sealant to seal an 8m length of joint. As standard we provide sufficient to seal the joints on one side only except in the case of double loading panels and vertical cantilever panels where we supply enough for both sides.  

Q: What is a “double loading panel”?

A: Panels designed to take loading from both sides such as a division wall in a bulk store or a retaining wall in a below ground tank. Unless specified otherwise all our horizontal panels are single loading and all our vertical panels are double loading. 

Q: Is it possible to cut or drill the panels?

A: Yes the panels can be cut using a petrol driven, diamond disc saw. The panels can be drilled but it is advisable to check the position of the steel strands and avoid drilling these if possible.
 

Q: How soon can the panel wall be used?

A: The panels are cured and ready for use when they leave our factory, therefore as soon as the wall is assembled it is ready for use. However, if applied, the mastic requires approximately 24 hours to go off (depending on ambient temperature). In the case of vertical cantilever panels the insitu foundation concrete must be allowed to cure and therefore typically the wall should not be used for 28 days after installation.
 

Q: What is the significance of the tongue and groove joint detail?

A: The tongue and groove joint allows the panels to act in unison when resisting an applied load. The panels share the load through the joints and this is a very important factor when calculating the overall performance of the wall.

Q: How are the panels fixed at the corners?

A: For horizontal panels where the panels meet at 90º an angle steel is bolted to the side panel to provide a fixing point for the clips. Typical Horizontal Fixing Arrangement pdf
 

Q: What happens if I damage a panel?

A: The panels are extremely robust and you are unlikely to damage them in normal use however if required they can be repaired with a high strength mortar. In the unlikely event that you do break a panel, in a horizontal panel system the panel can be unbolted, removed and replaced.
 

Q: Who fits the panels?

A: ACP offer a supply and fit service however the panels are designed to be simple to install using a telehandler/forklift and non specialist labour. Click the link for a copy of our installation guidelines

 
 

Enquiries

Floors / Stairs:

01900 814659

Walls, Agriculture and Bespoke:

01889 598660
 
 
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