Civil Engineering Reference
In-Depth Information
action of the compressive and tensile stresses that will cause collapse of the
beam. However, in contrast with type III behaviour, failure of the
compressive zone for type IV behaviour occurs when flexural capacity is
attained.
Figure 2.19
Typical stages of crack pattern of deep beams predicted by finite element analysis.
(Shaded regions represent regions subjected to a wholly compressive state of stress; single and
double short lines inside elements represent cracks occurring at previous and current, respectively,
load stages)
As with type III behaviour, the foregoing description of the causes of
failure characteristic of type IV behaviour complies with the concept of the
compressive force path. Consideration of the triaxial stress conditions has
been essential, not only to explain the development of tensile stresses within
the horizontal portions of the compressive force path, but also to identify the
source of strength of the inclined portion of the path after the occurrence of
diagonal-splitting. The existence of a triaxial wholly compressive state of
stress in the region of the loading point delays the extension of cracking into
