Effects of Fiber Distribution and Content on Performance of Engineered Cementitious Composite (ECC)

Abstract

The 21 dog-bone specimens with different fiber contents and fiber distribution (random chopped fiber or directional continuous filament fiber bundles) were designed and tested under uniaxial tension using domestic PVA (polyvinyl alcohol) fiber. High fiber content exerted positive influences on cracking stress, peak stress and deformation capacity of specimens with random chopped fiber, compared with the decrease shown in cracking stress of specimens containing directional fiber bundles. There were multiple cracks in specimens containing directional fiber bundles, while only 1–2 typical cracks could be shown in chopped fiber specimens after being broken. Random chopped fiber connected more closely with matrix compared with that only part of fiber bundles could contact with matrix. Double-fold line model and parabolic model could be used simultaneously to fit well with the uniaxial tension constitutive relations of engineered cementitious composite (ECC). Although the performance of PVA produced in China can not reach to the same level of those from Japan, there exists certain practical value in engineering according to its contribution to deformability of structure.

Keywords

fiber reinforced cement composites / fiber produced in China / fiber distribution / micromorphology / constitutive relation