| Title |
Shrinkage Stress Analysis of Concrete Slab in Multistory Building Considering Variation of Restraint and Stress Relaxation Due to Creep |
| Authors |
Kim Han-Soo ; Cho Suk-Hee |
| Keywords |
relaxation ; creep ; shrinkage ; shrinkage analysis ; construction sequence analysis |
| Abstract |
Shrinkage strains of concrete slab in multi-story building are restrained by structural members such as columns or walls. These can induce tensile stresses in concrete members and lead to cracks due to excessive shrinkage stress. In this study, a method of shrinkage stress analysis on concrete slab in multi-story building is proposed, which considers both material properties such as shrinkage and creep and construction sequence. The relaxation coefficient of shrinkage stress is defined and actual shrinkage stress is obtained by multiplying the defined coefficient to elastic shrinkage stress. Considering the variation of restraint and shrinkage strain, the analytical method for elastic shrinkage stress, which can be obtained by summing up the analysis result from the analytical models representing the construction sequence, is proposed. The results of 10-story example building show that shrinkage stresses of lower floors are greater than those of upper floors, that is, stresses of lower floors(1～2Fl.) only exceed tensile strength of concrete. The stress of 1st floor, which was the highest, resulted in less than 31% of the elastic stress of fully restrained member. |