| Title |
Shrinkage Stress Analysis of Concrete Slab in Multistory Building Considering Internal Restraint of Reinforcement Bar |
| Keywords |
Drying Shrinkage ; Creep ; Tall Building ; Slab ; External Restraint ; Internal Restraint |
| Abstract |
Shrinkage strains of concrete slab in multi-story building are restrained internally by reinforcement bar as well as externally by supporting members such as columns or walls. These strains can induce tensile stresses in concrete members and lead to cracks due to excessive shrinkage stress. In this study, a practical method of shrinkage stress analysis on concrete slab in multi-story building is proposed, which considers both internal restraint and external restraint variation resulting from construction sequence. The shrinkage stress due to external restraint is obtained by multiplying relaxation coefficient to elastic shrinkage stress. The additional shrinkage stress due to internal restraint is obtained by residual strain of the elastic analysis. A verification example was analyzed and compared by the proposed method and commercial analysis program that is capable of time-dependent analysis of concrete. The results of 10-story example building show that the internal restraint of reinforcement increases the shrinkage stress considerably at the slabs under loose external restraint. |