Can the Diameter of Longitudinal Bars of Extreme Edges of R/C Walls Halt Transverse Buckling?

One important aspect of seismic design of buildings with a dual reinforced concrete structural system
is the lateral stability of structural walls, when they face this danger mainly due to flexural overstrain.
The deep excursion in the yield region of the boundary parts of bearing walls increases dramatically
their flexibility and since at the same time they are liable, because of the earthquake vibration, to a
reversing axial loading (tension – compression), their lateral stability is at stake. The possibility of
failure because of lateral instability is limited significantly with the proper choice of an adequate
thickness, which is specified by (most) modern seismic codes as a percentage of the height of the
bottom storey. The current work investigates one parameter that may be affecting the stability of
structural walls. This parameter is the diameter of the longitudinal reinforcement of the boundary
edges of load-bearing walls. It contains an experimental research that tries to investigate the influence
of the diameter of longitudinal reinforcement to the ultimate bearing capacity of test specimens. It has
to be noted that in order to examine experimentally the influence of the diameter of longitudinal
reinforcement, test specimens of scale 1:3 simulating the boundary edges of structural walls were
used. These specimens were reinforced with the same or almost the same longitudinal reinforcement
ratios (2.68% - 2.79%) but had a different number of reinforcement bars of varying diameter. The
diameters of bars which were used were equal to 8 mm and 10 mm. The specimens which were
compared to each other contained (apart from bars of different diameter) a different number of bars
and consequently a different way of placement of these bars at the wall end sections.