Structural Behavior of Reinforced Shotcrete Slabs Incorporating Plastic Fibers

Shotcrete technology is developed to be used in places difficult to reach by traditional methods. The technique was developed to apply to strengthening work, slope stabilization, tunnel lining, and constructed structural members. These applications necessitate the use of a shotcrete mixture to enhance the strength and crack resistance. As a result, incorporating fiber is necessary to eliminate these issues. The American Concrete Institute's (ACI) code guided the design of eleven one-way slab specimens. Three types of fiber were studied: Waste plastic fiber (PET), macro-synthetic polypropylene fiber (PP), and hybrid fiber (PET+PP), with three percentages for each type: 0.35%, 0.7%, and 1% by volume of the mixture. The test results indicated that the shotcrete reinforced with polypropylene fiber had better mechanical properties than the plain shotcrete. On the other hand, shotcrete containing 1% waste plastic fiber showed better flexural performance of the one-way slab through an increase in the ultimate load, energy absorption, stiffness, and ductility by about 12.66%, 135.978%, 5.7%, and 47.2%, respectively, due to the mechanical work of the fiber bridging the concrete matrix, which could improve resistance for formation and development cracks.