Demoulding is separating the concrete from his form. this is done with the help of a mould release agent that makes it easy for the concrete to come out of his form or mould. This can be done on two different ways:
Barrier
The release agent provides a physical barrier between the form and the concrete (petroleum based products, soaps, synthetic resins, waxes,...)
Reactive
The release agent contains fatty acids or other ingredients that react with the free lime in fresh concrete to produce a metallic soap interface between the form and the concrete. Visual seen as a thin layer of dust between the form and the concrete. 

In the concrete precasting demolding is done off-site using a mould or form under controlled conditions. Nevertheless we make an important distinction in the way of curing during production: 
Hardened in the mould 
The concrete is cured inside the form. 
Immediate release
The concrete is cured outside the form

Concrete precasting is not an exact science and that there are many variables that influence the result. The most common problems you may encounter in the concrete precasting are:

• SURFACE VOIDS
• CONCRETE DUSTING
• DISCOLORATION OF THE CONCRETE
• STICKING CONCRETE
• CORROSION ON THE MOULDS

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