Synopsis
This study is concerned with the effect of strain-hardening upon the response of continuous reinforced concrete beams. An analysis including the effect of strain-hardening of the steel is developed to determine moment-rotation relationships of a beam section, and the results are verified experimentally. These moment-rotation relationships are then used in a piecewiselinear analysis in which the non-linear effects are represented by discrete strain-hardening hinges in order to predict the behaviour of the continuous beams. Analytical and experimental results showed good correlation. The increased load-carrying capacity of under-reinforced beams above that predicted by the simple plastic theory is therefore attributed to the strain-hardening of the steel. A reinforcing parameter called the ‘strain-hardening index’ is introduced to determine the effect of yield range and strain-hardening of the steel upon the strength and rotation capacity of the beam. Lastly, it is shown that the energy absorption capacity is only very slightly affected by the shape of the stress-strain curve of the reinforcing steel.
