ABSTRACT

There are two principle forms of binder typically used. In traditional buildings lime is the most commonly used but, more recently, cement has become the favoured material for modern buildings. They differ considerably in the way they set: lime sets by carbonation and cement by hydration. The comparison between these two methods of setting goes a long way to understanding the differences between the two products. A set achieved by carbonation produces a material composite which retains an ability to breathe or be permeable. The resultant set using cement or cement-based products achieves a chemical set by hydration which does not retain permeable properties and, therefore, does not allow the resultant set product to breathe and is impermeable to the passage of moisture.