In tall concrete buildings, columns and core walls experience axial shortening due to combined effect of heavy loading, shrinkage and creep. If the stress distribution across the floor plan is disproportionate, columns and core walls within a single storey may shorten by different amounts. This differential can introduce extra loads and moments within elements and also induce distortion of attached service elements such as claddings, pipes, partitions, that leads to serviceability problems. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. Calculation of exact values of axial shortening is not a straight forward task since it depends on a number of parameters such as the type of concrete, reinforcement ratio, and the rate and sequence of construction. A comprehensive study on the prediction models of concrete properties related to axial shortening was conducted. The performance of ACI models for prediction of the concrete properties was evaluated. In order to analytically solve the problem, finite element software MIDAS Gen considering shrinkage and creep effect is applied on a G+40 storey RC frame structure with internal core wall.
Column shortening, Construction stage analysis, Creep, Deformation, High rise buildings, Shrinkage
