Abstract:
In non-steel manufacturing countries like Sri Lanka, where the cost of heavy rolled steel
sections are very high, composite floor trusses tend to provide an economical solution in
achieving moderate spans in the range of 8m-12m. A high degree of service integration can
be provided in these floor systems by allowing rectangular openings, as often preferred in
constructing high-rise buildings. However, allowance of rectangular openings in the web
creates additional local moments in the comers of the openings, which are generally known
as "vierendeel" moments and render the composite truss statically indeterminate. Failure to
account for these vierendeel moments in composite floor structures often leads to undesirable
cracking in the concrete floor slab.
