In this paper, large deformation analysis is carried out on uniformly loaded
orthotropically reinforced concrete rectangular slabs that have one free edge and
different restraints on the other edges. For the purpose of such analysis, the slabs
are assumed to behave in a rigid-perfectly plastic manner and to yield under the
combined effect of bending and membrane action. Two cases are analysed; the
case of a slab having two adjacent edges fixed- one edge simply supported and one
edge free, and the case of a slab having two adjacent edges simply supported- one
edge fixed and one edge free.
Results of the analysis indicate considerable enhancements in the load carrying
capacity of such slabs above those predicted by Johanson's simple yield line
theory(1).The amount of the load enhancement in a particular slab is found to
depend on many parameters such as the steel ratio rx
, orthotropy ratio g,
compressive strength of concrete fʹc , yield stress of steel fy , and the slab aspect
ratio Ly/Lx, such that a higher enhancement in load is achieved for a slab having a
higher value of fʹc but lower values of Ly/Lx , rx
+ , g and fy .