This paper presents a study of the strength (non)compliance of structural concretes produced in Brazil, and a study of the detrimental effects of non-compliance in reliability of short columns subject to axial compression. The investigation is based on experimental results of over five thousand concrete samples from different parts of Brazil. Results show that a significant part of these concretes do not reach the characteristic strength specified in design. As a consequence, these concretes should be considered non-compliant, and mitigation measures should be adopted (design revision, further testing, structural reinforcement, load restrictions and demolition/reconstruction). The study also investigates the impact of concrete strength non-compliance on the reliability of short columns subject to axial compression, when mitigation measures are not adopted. In reinforced concrete, short columns are the structural elements whose resistance most directly depends on the compressive strength of concrete. One consequence of concrete strength non-compliance is that the theoretical equation relating mean concrete resistance to specified concrete strength does not apply. Using an alternative expression, derived from the experimental results, a significant reduction in reliability of short columns is observed, due to the noncompliance of concretes produced in Brazil. These results testify to the importance of a rigorous control in the reception of concretes at construction sites, as well as in the control of the required mitigation measures, when noncompliant concrete is received.
non-compliance of concrete strength; concrete structures; structural safety; structural reliability; short columns; axial compression