Effect of Fiber Type and Volume Fraction on Fiber Reinforced Concrete and Engineered Cementitious Composite Mechanical Properties

Engineered cementitious composites (ECC) are an ultra-ductile cement-based composite material reinforced with short randomly distributed fibers. It differs from fiber reinforced concrete (FRC) in that it has a distinct ductile behavior. The study aims to assign mechanical properties, such as tensile, flexural, and compressive strength using locally available fiber rather than polyvinyl alcohol (PVA) fiber, which is not widely available in many countries, to ECC. PVA fiber is also very expensive. Instead of PVA, lightweight fibers, such as polypropylene, polyolefin, and glass fiber, as well as heavyweight fibers, such as steel fiber, were used. To assess the mechanical properties, the influences of curing, fiber volume fraction (2%, 4%, and 6%), fiber type, and fiber hybridization were adjusted in this study. The formation of multiple cracks along the specimen is the governing factor in ECC formation. The test results show that increasing the fiber volume fraction improves flexural and tensile strength. Water curing increased compressive, tensile, and flexural strength. Lightweight fiber hybridization has no effect on compressive strength, whereas heavyweight fiber hybridization improves compressive strength. For tensile and flexural strength, hybridization was associated with an improvement in all mechanical properties. The hybridization of lightweight fiber achieved ECC behavior at a lower volume fraction than the use of a single fiber volume. Relationships between tensile strength and flexural strength depending on the compressive strength of ECC were driven by demonstrating high performance.

Automated summary

Engineered cementitious composites (ECC) is a ductile cement-based composite material reinforced with short randomly distributed fibers. This study aimed to evaluate the mechanical properties of ECC using locally available fiber instead of the expensive and less accessible polyvinyl alcohol (PVA) fiber. Results showed that increasing the fiber volume fraction and water curing enhanced the flexural and tensile strength of ECC. Lightweight fiber hybridization had no impact on compressive strength, while heavyweight fiber hybridization improved it. Hybridization improved both tensile and flexural strength of ECC. The relationship between tensile strength and flexural strength was influenced by the compressive strength.