Fiber reinforced shotcrete
The conventional unreinforced concrete is a brittle material. Similarly, the unreinforced shotcrete is a brittle material that cracks when subjected to tensile stresses. The addition of fibers to shotcrete will improve the properties of shotcrete. The ductility and impact resistance will be enhanced. The reinforced shotcrete material will not only be capable of enduring post cracks loading but also often displays an increase in ultimate strength, in particular, the tensile strength. The used fibers can be steel fibers, glass fibers, and synthetic fibers.
The glass fibers are made from a special zirconium alkali-resistant (AR) glass to resist the deterioration in high alkaline Portland cement. Glass reinforced shotcrete required a special gun and delivery system. The process of applying glass-reinforced shotcrete is different from applying conventional shotcrete. Spray-up is the term used for applying glass-reinforced shotcrete. The GFRS used to construct lightweight panels for building cladding. Moreover, it used for special architectural features such as the construction of simulated rock structures for animal exhibits at zoos.
Synthetic fibers are made of nylon, polypropylene, polyethylene, polyester, and rayon. The polypropylene fibers have been used extensively to produce fiber-reinforced shotcrete. The using of synthetic fibers is beneficial in terms of decreasing the shrinkage cracks. The Typical applications for fiber-reinforced shotcrete are for tunnel linings, surface coatings on rock and soil, slopes, structures, embankments, or other structures that may be subject to high deformations or where crack control is needed.