The column formwork systems now available are normally modular in nature and allow quick assembly and erection on site while minimising labour and crane time. The forms, made of steel or aluminium sometimes with a timber form-face lineer, can be adjusted on site to give different column sizes. They have a variety of internal surfaces depending on the concrete finish required. Metal formwork systems can have integral concreting platforms with guard rails and access equipment including ladders. This reduces the need for independent access. In some systems the props used to stabilise the column formwork are integral. The metal forms are easy to clean and reuse with little waste generated compared with traditional formwork.
An alternative approach for circular columns is to use disposable formwork, which consist of cardboard tubes with a plastic liner. These are left in place until the concrete has gained sufficient strength and then the cardboard is carefully removed. For this type of formwork, working platforms for concreting have to be erected separately to allow access to the top of the column.
Further information may be found in Formwork for modern, efficient concrete construction, by Rupasinghe and Nolan, published by BRE Press and in the CONSTRUCT A guide to the safe use of formwork and falsework.