Utilizing Fiber Reinforced Concrete as the Concrete Face of Rockfill Dams

Construction of concrete faced rockfill dams (CFRD) includes pouring rock materials as the main body of the dam and compacting the rockfill to an acceptable compaction level. Then, a reinforced concrete slab is constructed on the upstream surface of dam to transfer water pressure to the rockfill materials. Considering the high permeability of rockfill materials, the concrete slab serves as a sealing element on the upstream side. Indeed, the required characteristics of concrete face are adequate flexibility in case of long-term settlement of dam, durability and its sufficiency in waterproofing the dam. In this study, to improve the quality of concrete face, increase its flexibility, optimize the construction cost and enhance the bearing capacity of concrete in tension, developed by bending moment in the face slab, three types of prevalent fibers (polypropylene, MEXO200 and steel) are utilized. The performance of each fiber is compared with the conventional reinforced concrete specimens by conducting some bending tests. Furthermore, carrying out numerical simulation, the efficacy of each fiber on performance of face slab is investigated. Based on the results, the fibers, especially the steel fibers, are suitable to substitute rebars of the conventional reinforced concrete employed as the concrete face of CFRDs. The steel fiber reinforced concrete has adequate capacity and ductility to mitigate the expected deformations from reservoir loading on the upstream face of CFRDs.