Cyclic response of reinforced concrete members at low temperatures

An experimental study was undertaken to investigate the influence of cold temperatures on the seismic behavior of reinforced concrete members. This paper summarizes the results of Phase I of a multiphase research project that consisted of the reversed cyclic testing of four identical large scale reinforced concrete circular columns subjected to temperatures ranging from -40 degrees C (-40 degrees F) to 20 degrees C (68 degrees F). An extensive literary review is also presented. It was found that most of the past research focused on the material level, i.e., the independent behavior of plain concrete and reinforcing bars. Data collected from past works were complemented with the results obtained from the material tests performed in this research, and used to develop empirical equations for the estimation of the mechanical properties of concrete and steel reinforcement at low temperature. Past research shows an increase in strength without any loss in the deformation capacity of plain concrete and reinforcing steel bars tested at low temperatures. The results of this study show a reduction in the displacement capacity of reinforced concrete members tested at freezing temperatures.