STAGED NONLINEAR STATIC ANALYSIS OF SHRINKAGE IN REINFORCED CONCRETE ONE-WAY SLABS

Abstract

The cracking due to restrained shrinkage at early ages of concrete is one of the shortcomings of concrete, which may reduce its sustainability. Staged nonlinear static analysis adopted by SAP2000 software is used to analyze one-way slabs applied to restrained shrinkage. Staged nonlinear static analysis has been improved using the concept of cracked element and the proposed model showed good correlation with test results. Creep strain calculated by CEB-FIP cannot be used correctly with shrinkage at early ages of concrete (first three months), and a modification factor has been suggested in the present research. The modification factor is dependent on the steel ratio. Shrinkage relaxed due to creep has been found slightly affected by the steel ratio, which may be considered constant and equals to 60% approximately. Steel reinforcement will control crack width by reducing the restrained length of shortened concrete due to shrinkage, which is equal to the distance between multiple cracks.