| Title |
Design of ECC(Engineered Cementitious Composite) Matrix Compositions Based on Micromechanics and Steady-State Cracking Theory |
| Authors |
Kim Yun-Yong ; Ha Gee-Joo ; Shin Jong-Hark |
| Keywords |
ECC ; Matrix Design ; Micromechanics ; Steady-state Cracking ; Tensile Strain-hardening ; Multiple Cracking |
| Abstract |
This paper presents both analytical and experimental studies for the design of ECC (Engineered Cementitious Composite) matrix compositions by using raw materials commercially available in Korea. We employed micromechanical principle and steady-state cracking theory as the tools for this goal. A single fiber pullout test and a wedge splitting test were initially performed to measure the fiber-matrix bond properties and the fracture toughness of mortar matrix, respectively, which are used for analyzing fiber bridging behavior. We then performed micromechanical analyses, followed by applying steady-state cracking theory in order to properly select ECC matrix composition suitable for achieving strain-hardening behavior at a composite level. Subsequent direct tensile tests demonstrated that ECC produced in the present study exhibited high ductile uniaxial tension property, represented by a maximum strain capacity of around 4%, which is much larger than that of normal concrete by two-order of magnitude. Both ductility and tensile strength of the composite produced with slag were measured to be significantly higher than those of the composite without slag. This is most likely because the slag particles contribute to improving toughness ratio at the same water-binder ratio, and to enhancing fiber dispersion which is incorporated with the contribution of the oxidized grain surface of slag. |