Deformation of cracked net-reinforced concrete walls

The deformation and crack width in concrete walls of slabs, plates, panels, and shells reinforced by a regular rectangular net of steel bars and subjected to in-plane (membrane) internal forces is analyzed taking into account the frictional-dilatant behavior of rough interlocked cracks, and for the dowel action of bars at crack crossings. The tension-stiffening effect, i.e., the restraint of the bars between the cracks due to their embedment in concrete, is also taken into account. Numerical computer studies are carried out. Reinforcement designs obtained from equilibrium conditions alone on the basis of either the classical frictionless approach or the recent frictional (slip-free) approach are compared in terms of the resulting crack widths. It is found that the use of frictional equilibrium design based on a low friction coefficient (0.75) leads to a much smaller crack width than the classical frictionless design when the reinforcement is laid in a direction which significantly deviates from the principal internal force direction. The influences of bar diameter and crack spacing on the crack width are also determined. The deformation analysis in which the frictional dilatant behavior of cracks, the dowel action, and tension stiffening are neglected leads to rather different values for the crack width.