| Title |
Stiffness Reduction Factors of Flat Slabs Based on Loading Characteristics |
| Authors |
Choi Jung-Wook ; Song Jin-Gyu |
| Keywords |
Flat Plate Structures ; Effective Beam Width Model ; Stiffness Reduction Factors ; Service Gravity Loads ; Creep and Shrinkage Effects |
| Abstract |
The flexural stiffness of flat slabs is reduced by cracking due to externally applied loads and volume changes. To reflect this phenomenon in an effective beam width model, the stiffness reduction factor, which is equal to the effective slab stiffness divided by the gross slab stiffness, is commonly used. Many techniques for defining the stiffness reduction factor have been proposed. However, these methods fail to sufficiently explain the various stiffness changes of the actual slab. To solve this problem, a detailed study on the stiffness reduction factor is performed, assuming that flexural stiffness of members is inversely proportional to deflection. In the study, the slab stiffness reduction caused not only by service gravity loads but also due to the combined effects of creep and shrinkage is mainly considered. Based on the results, the methods for calculating the stiffness reduction factor of flat slabs based on loading characteristics are developed. The proposed methods are verified by comparisons with the experiments with multi-panel and the analysis models with stiffness reduction. |