Rheological-dynamical model of concrete and its application on RC beams

Abstract

An improved analytical model based on rheological-dynamical analogy (RDA) is briefly explained and used for the analysis of concrete cylinders under compression. The approach involves standard mechanical properties such as compressive strength, elastic modulus, concrete density and Poisson’s ratio for the prediction of both the ascending and the descending branch of the stress–strain curve. Our own experimental data for arbitrarily selected high strength concrete with high deformability was analyzed. Further, the validity of the RDA model is checked against tests of other authors for one normal concrete and for six recycled aggregate concrete mixtures. To demonstrate the capabilities of the improved model, using analytically established stress–strain relations for analyzed samples, the moment-curvature relations and ductility of reinforced concrete beams in bending were numerically examined. The analysis showed that the ductile behavior of beams made of concrete with recycled aggregate can be achieved by limiting the reinforcement ratio to 0.01 if the recycled concrete aggregate is used and to 0.02 for recycled brick aggregate.