Basics in Building Construction

Building Components And Types

Lesson 17 and 18 : Arches

Classification Based On Materials Of Construction

Removal Of Centering

When the arch has developed sufficient strength, the centering can be removed. No load should be placed on the arch unless the centering has been removed. For small spans, the removal of centering is done by loosening the folding wedges.

When the span is more than 7 m, a sand box method can be used for loosening, so that shocks are avoided. A sand box is placed below the prop. Sand is filled in box with a plugged hole at its bottom. Prop rests on the steel plate placed on the top of sand. In order to lower the centering, plug is taken out due to which the sand flows out and lowers the prop gradually.