EFFECT OF FIBER VOLUME FRACTION ON THE OFF-CRACK-PLANE FRACTURE ENERGY IN STRAIN-HARDENING ENGINEERED CEMENTITIOUS COMPOSITES

In this paper, the results of an experimental study on the effect of f iber volume fraction on the off-crack-plane fracture energy in a strai n-hardening engineered cementitious composite (ECC) are presented. Unl ike the well-known quasi-brittle behavior of fiber-reinforced concrete , ECC exhibits quasi-ductile response by developing a large damage zon e prior to fracture localization. In the damage zone, the material is microcracked but continues to strain-harden locally. The areal dimensi on of the damage zone has been observed to be on the order of 1000 cm( 2) in double cantilever beam specimens. The energy absorption of the o ff-crack-plane inelastic deformation process has been measured to be m ore than 50% of the total fracture energy of up to 34 kJ/m(2). This ma gnitude of fracture energy is the highest ever reported for a fiber ce mentitious composite.