OPTIMAL UTILIZATION OF TIMBER POLES AS STRUCTURAL MEMBERS OF FORMWORK

Abstract

Timber poles of the type "Mirunda" are commonly used
in East Africa as formwork support structures for casting
of reinforced concrete slabs, beams and canopies. It is
also widely known that the "Mirunda" poles as structural
members of formwork are massively used without any
structural consideration and guidance. This common
practice has resulted into wastage of natural resources
and escalated construction costs. This study has
attempted to establish the load bearing capacity of
randomly selected "Mirunda" poles through laboratory
testing. Using an existing construction site as a case
study, the results have been used to establish the actual
number of timber poles required to support freshly cast
reinforced concrete slabs, beams and canopies. The
loading has been assumed for normal accessibility as per
specifications in BS 6399: Part1 (1984).with a dynamic
factor arising from the impact of dropping the concrete
onto the formwork as well as the dynamic effect of the
concrete vibrating machine. A comparison has been
made between the actual requirement and the quantity of
timber poles counted on site. On basis of the study
findings appropriate recommendations have been
provided on how "Mirunda" poles can be optimally
utilized as structural members of formwork.