Evaluation of creep and shrinkage effects in composite tall buildings

Abstract

SUMMARYIn a composite tall building, adjacent vertical members undergo differential time‐dependent deformations due to creep and shrinkage. Highly elaborate, complex and requiring large computational effort procedure, utilizing stress transfer method, age‐adjusted effective modulus method (AEMM) is available to evaluate creep and shrinkage effects in a composite building.Recently, a simple procedure and requiring lesser computational effort, utilizing AEMM has been presented for concrete and composite buildings. Studies comparing deflections and axial forces in reinforced concrete frames with those obtained from the procedure available in literature (using stress transfer method, RCM) have been reported.In this paper, suitability of the above procedures for evaluation of creep and shrinkage effects in composite buildings has been demonstrated. Studies are reported for typical creep shrinkage parameters. It is shown that the error to determine axial forces from AP(AEMM) is small for composite frame–shear wall systems with very low beam stiffness (Ib = Ic/100). Use of CP(AEMM) is warranted for the frame–shear wall systems even with low beam stiffness (Ib = Ic/20). Copyright © 2010 John Wiley & Sons, Ltd.