Behaviors of Strain-hardening Cementitious Composite Columns under Eccentric Compression

Engineered cementitious composite (ECC) is a type of high-performance composite with pseudo strain hardening behavior and multiple cracking properties.The cracking and durability problems induced by concrete brittleness can be effectively avoided by substituting concrete with ECC in building structures.In this study,eight steel-reinforced columns with various longitudinal reinforcement ratios were tested under eccentric compression.The test results show that steel-reinforced ECC (R/ECC) columns exhibit superior performance to reinforced concrete (RC) columns in terms of load-carrying capacity,ductility,crack control ability,and damage tolerance under the same conditions and with high eccentricity.Significant concrete spalling occurs in the RC columns,while no sign of ECC spalling is observed in the R/ECC columns,owing to the fiber bridging effect of ECC.In the RC columns,the crack width reaches as high as 2 mm prior to the ultimate strength,while in the R/ECC column, the maximum crack width remains constant at approximately 60 μm with an increasing compression load.In addition to experimental work,a theoretical calculation model was proposed to predict the moment-curvature response of the R/ECC column.The prediction results are in strong agreement with test data.Furthermore, parametric studies were conducted to compare the load-moment capacity (Nu-Mu) interaction curves between RC column and R/ECC column. © 2019, Department of Journal of the China Railway Society. All right reserved.