Simulation and Strength Prediction of Reinforced Recycled Aggregate Concrete Short Columns

This paper focuses on detailed experimental and numerical investigations carried out to study the behaviour of reinforced recycled aggregate concrete (RAC) short columns subjected to uniaxial compression. Experimental investigation includes the study of the behaviour of short reinforced RAC columns in which 30% of the natural coarse aggregates were replaced with recycled coarse aggregates and percentage of longitudinal steel reinforcement was also varied. Maximum axial load and failure modes of columns were observed. Numerical investigations were also carried out to simulate the behaviour of short RAC columns that were tested during the study along with some other columns of same size tested in another study by the authors. Software used in the simulation was first tested by modelling and simulating behaviour of columns obtained from past researches. Results were compared in terms of ultimate load carrying capacities and failure patterns. Results obtained experimentally were found to be in close agreement when compared with the results predicted through simulation. Load carrying capacities of the tested columns were also compared with equations proposed by different design codes. Lot of variation was observed in the peak loads predicted by the equations proposed by different design codes as they have been proposed for natural aggregate concrete (NAC) columns and a correction factor needs to be introduced depending on the physical properties of RCA if they are to be used for RAC.