| Engineered fiber reinforced Cementitious Composite is a kind of high performance fiber reinforced cement composites which has high toughness,strong energy absortpion,high ductility.ECC materials,used in engineering structural,can obviously improve the seismic performance,crack resistance and durability of the structure.In this paper,the uniaxial compressive experiments of ECC square short columns were conducted.Based on the analysis of test results of this paper and studying team,the strength and deformation performance of confined ECC columns were studied,the stress-strain curve equation of confined ECC columns was proposed to give reference for the nonlinear analysis on the loading process.The volume stirrup ratio,stirrup diameter and spacing and the ratio of section height and width are the main parameters in this paper.The results indicate that the specimen which has higher volume stirrup ratio,smaller stirrup diameter and spacing or smaller ratio of section hight and width has a more gentle descending part of stress-strain curve,while the ascending part has little change.These specimens'ductility have an obvious improvements.The change of these parameters has some influence on peak stress and peak strain,but has larger inpact on?0.85.By theoretical analyzing the test results of this paper and studying team,the calculation formula between peak stress,peak strain,ductile ratio of confined ECC columns and effective confinement index were proposed.And the load ultimate bearing capacity were proposed,which are safe when compared with experimental results and may be used to analyze the ultimate bearing capacity of axially loaded short columns confined with stirrups.Based on the features of stress-strain of confined ECC short columns,the calculation model of confined ECC short columns was suggested.The predictions are in good agreement with the experimental results,therefore,it can be used for reliable theory of finite element analysis of confined ECC short columns. |
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