The shear assessment of concrete beams with a honeycombed zone present in the high shear region
A honeycombed zone in a concrete structure is among the forms of defects that can be found in concrete structures. In this study, the effects on the shear capacity of a concrete beam are investigated when a honeycombed zone is present in the high shear region. The honeycombed concrete was simulated using an uncompacted no-fines concrete mix. Tests were carried out on rectangular beams with a honeycombed zone introduced at various locations within the high shear region of the beam. The honeycombed zone was square with the size of about a third of the effective depth of the beam. Two strengths of normal concrete were investigated. The study found that, in a beam with a honeycombed zone, a diagonal crack could form early and the shear capacity of a beam could be reduced. The severity of these effects varies with the location of the honeycombed zone. Modifications were proposed to an existing plastic analysis method to take into account the strength of the honeycombed concrete. Condition factors derived from the test data were also proposed to be applied to the plastic analysis in assessing beams with a honeycombed zone. A honeycombed zone simulating a construction joint in a beam was also investigated analytically and compared with the data from 4 tests.