Performance of Low Modulus Fibers in Engineered Cementitious Composites (ECCs): Flexural Strength and Pull out Resistance

Cement based materials are brittle in nature. Fibers have been used to improve flexural/tensile behaviors of the cementitious materials from one hundred years ago. Recently, a new generation of high performance fiber reinforced cementitious composites (HPFRCCs) has been introduced by Professor V.C. Li which was called Engineered Cementitious Composite (ECC). ECC showed incredible flexural and tensile strengths as it was called as flexible concrete by some researchers. Usually, high modulus fibers have been used in ECCs as reinforcement. In this research, homemade low modulus fibers (acrylic, nylon 66 and polypropylene) were used as reinforcement in ECC. Flexural strength test were performed on the ECC sheets. Also, Pull out test was performed to determine adhesion energy and toughness between the fibers and the matrix. It was found that low modulus fibers caused lower flexural strength and bonding to matrix than PVA fibers. However, they were found as suitable fibers for products with good cost-quality balance especially for construction purposes.