Efficiency comparison of natural vs artificial fibers on the shear behavior of reinforced-ECC members

Improving the durability of reinforced concrete has become a concern due to the high maintenance cost and safety aspects. In specific, the failure due to shear loading can be catastrophic and requires modifications in the micro-structure of concrete with improved ductility characteristics. Though engineered cementitious composites (ECC) are emerging as a substitute for traditional concrete, their high cost (3 times) limits their practical applicability. This study attempts to compare the effectiveness of the novel and sustainable bio-fiber-reinforced ECC beams when compared with the readily accessible artificial fiber-based ECC members. The proposed research compares the efficiency of using bio-fibers for instance kenaf, pineapple, flax and hemp to standard ECC made of PVA, polypropylene (PP), or a hybrid of PVA and PP. The test sequence contains testing of sixteen ECC beams with 2.0% discrete natural or artificial fibers as specified above. In addition to the full-scale tests, a nonlinear finite element analysis was carried out by using the commercially available software ABAQUS and validated with benchmark experiments. Test outcomes showed that the use of natural fibers was very effective in increasing the ultimate shear resistance by a perfect crack-bridging mechanism on par with the artificial fiber-based ECC sections. Specifically, the inclusion of flax fibers attained the highest shear load of 56.2 kN with a corresponding energy absorption capacity of 477.5 Joules. Furthermore, the finite element analysis predicted peak shear capacity that matched the experimental results.