Moffat, R., Jadue, C., Beltran, J. F., & Herrera, R. (2017). Experimental evaluation of geosynthetics as reinforcement for shotcrete. Geotext. Geomembr., 45(3), 161–168.
Abstract: One of the commonly used stabilization systems for rock tunnels is shotcrete. This fine aggregate mortar is usually reinforced for improving its tensile and shear strength. In deep tunnels, its capacity to absorb energy has been recently considered for design purposes, as large displacements of the wall are expected. Two of the most used materials of reinforcement are steel welded-wire mesh and fibers (steel or polypropylene) in the shotcrete mix. This study presents the results and discussion of an experimental test program conducted to obtain the load-deformation curves of reinforced shotcrete, according to ASTM C 1550, using geosynthetics grids and geotextiles as alternative reinforcement materials. In addition, plain shotcrete and steel welded-wire mesh reinforced shotcrete specimens are also considered in the experimental program as benchmark cases. The experimental results are analyzed in terms of maximum strength and toughness. Results show that the use of geosynthetics as a reinforcement material is a promising alternative to obtain shotcrete with energy absorption capacity comparable with the most common reinforcement materials used. (C) 2017 Elsevier Ltd. All rights reserved.
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Norambuena-Contreras, J., Gonzalez-Torre, I., Vivanco, J. F., & Gacitua, W. (2016). Nanomechanical properties of polymeric fibres used in geosynthetics. Polym. Test, 54, 67–77.
Abstract: Geosynthetics are composite materials manufactured using different types of polymeric fibres, usually employed as anti-reflective cracking systems in asphalt pavements. Materials that compose geosynthetics can be damaged due to mechanical and thermal effects produced during the installation process under hot mix asphalts. In this paper, different polymeric fibres extracted from geosynthetics have been evaluated using nanoindentation tests. The main objective was to evaluate the effect of installation process (dynamic compaction and thermal damage) on the mechanical behaviour of individual polymeric fibres at nano-scale. To do this, elastic modulus (E) and hardness (H) of three different polymeric fibres commonly used in geosynthetics (polypropylene, polyester and polyvinyl-alcohol), in two testing directions and under two different states have been studied. Main conclusions of this work are that mechanical properties of geosynthetics individual fibres can change after installation, producing changes in the behaviour of geosynthetics at macro-scale with consequences in the pavement functionality, and that these changes are different depending on the material that composed the fibres. (C) 2016 Elsevier Ltd. All rights reserved.
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