Tensile Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composite with Respect to Fiber Volume Fraction

초록

Concrete has high compressive strength, but low tensile strength, bending strength, toughness, low resistance to cracking, and brittle fracture characteristics. To overcome these problems, fiber-reinforced concrete, in which the strength of concrete is improved by inserting fibers, is being used. Recently, high-performance fiber-reinforced cementitious composites (HPFRCCs) have been extensively researched. The disadvantages of conventional concrete such as low tensile stress, strain capacity, and energy absorption capacity, have been overcome using HPFRCCs, but they have a weakness in that the fiber reinforcement has only 2% fiber volume fraction. In this study, slurry infiltrated fiber reinforced cementitious composites (SIFRCCs), which can maximize the fiber volume fraction (up to 8%), was developed, and an experimental study on the tensile behavior of SIFRCCs with varying fiber volume fractions (4%, 5%, and 6%) was carried out through direct tensile tests. The results showed that the specimen with high fiber volume fraction exhibited high direct tensile strength and improved brittleness. As per the results, the direct tensile strength is approximately 15.5 MPa, and the energy absorption capacity was excellent. Furthermore, the bridging effect of steel fibers induced strain hardening behavior and multiple cracks, which increased the direct tensile strength and energy absorption capacity.

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