Numerical simulation of shrinkage and creep in patch-repaired axially loaded reinforced concrete short columns

This paper presents numerical results obtained from finite element simulations of the time-dependent behaviour of moderately loaded patch-repaired reinforced concrete short columns. Patch repair is a structural concrete repair method in which damaged concrete is replaced with one of a wide range of materials. Relative to the concrete substrate, the patch repair materials used in this study had different properties, such as the elastic modulus, shrinkage and creep. A priori, it would appear that simple theory such as the engineer's theory of bending cannot be used to quantify the behaviour of the patch-repaired member. Experimental evidence needed to clarify such issues remains scarce. The finite element simulations performed in this study indicate that shrinkage and creep cause the progressive shedding of the load carried by the patch repair to the concrete substrate. Finite element results compare favourably with the predictions of the engineer's bending theory. Relative to test results some qualitative agreement is observed though there is significant quantitative deviation.