The advantages of using work-hardening, high-performance fiber reinforced concrete (HPFRC) in critical areas of earthquake resistant structures are increasingly recognized. Due to their ductile behavior HPFRCs is particularly attractive for use in areas where a large inelastic deformation capacity is needed to withstand the demands caused by a severe earthquake. Test results showed that HPFRCs serve as a substitute for specific details of seismic reinforcement by providing additional shear strength and confinement, which could lead to important simplifications in the construction of earthquake resistant structures.
In 1987, Naaman proposes to classify the fiber reinforced concrete is based on the tensile behavior after cracking (Fig. 1). When the rate of hardening behavior has been observed, the mixture is classified as high-performance fiber reinforced cement (HPFRC). When the strain softening behavior is observed, the mixture is classified as a simple fiber reinforced concrete (FRC).
After the first crack occurs HPFRC subjected to direct tension, the fibers bridge the crack to carry a greater load, thus increasing the composite cracking. This cracking process, which eventually leads to a dense mass of fine cracks, damage continues to locate the (substantial removal of the fiber) is one or a few cracks, traction typically between 0.5 and 3%. FRC on a regular basis, on the other hand, because the fibers can not carry more load after cracking, the location of damage will start as soon as the first structural cracking occurs.
The fibers also increase the compression behavior of concrete, especially by increasing the voltage on capacity. HPFRCs has shown to exhibit a very similar behavior in the confined concrete, load capacity exceeding 1%. This suggests that the confinement reinforcement relaxations are possible when using HPFRCs than concrete.
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