Economy in Form-work
it may be noted that the total cost of concrete construction includes the cost of form-work as well.Construction of form-work involves considerable expenditure in terms of cost of material, cost of labour for fabrication, erection and removal of form-work time element.
in case of buildings, the cost of form-work may vary range between 30 to 40% of the cost of concrete work.
in case of special structures like bridges, tall chimney, dams etc. the cost of form-work may range between 50 to 100% of the cost concrete work, or even more.
Following steps should be followed to effect economy in the cost of form-work .
(i) The Building should be planned in such a way that there are minimum number of variations in the size of rooms, floor area etc. so as to permit re-use of the form-work moulds repeatedly.
(ii) The Scheme of the form-work should be efficiently planned and suitably designed to determine the most economical but safe sizes of different components including the supports or props.
(iii) the Form-work should be constructed in such a way that timber (where used) is cut to the minimum and it can be struck off with ease an in such works re-use with least damage.
(iv) In case the form-work is made out of rough timber and is not constructed properly, the resultant concrete surface will be irregular and full of defects.
The expenditure involved in rectification of defects in such works is invariably more than the saving made in the cost of form-work.
