Reinforcing of Sand With 3D Printed Fibres – Review of Properties, Fabrication of Fibres and Initial Testing Programme

Abstract

Fibre reinforcement is an effective method of soil improvement that presents an alternative solution to other more common methods of ground reinforcement such as mechanical stabilization by geosynthetics (geogrids, geotextiles, geocomposites, etc.). Research activities in this area are being carried out, but the main disadvantage of currently used fibres is their uniform cross-section and usually smooth surface given by available production methods. This study presents an alternative way of fabrication of synthetic fibres – utilization of fused deposition modelling (3D printing). With the rapid development in commercially available 3D printing techniques, it is now possible to refine the shape and dimensions of 3D printed objects to a tenth of a millimetre. The review of the basic index and mechanical properties of fibre-reinforced soils is presented in the first part of the paper. The second part is devoted to the description of the production process of fibres including the suitability analysis of materials used for 3D printing. Finally, the initial testing programme of fibre-reinforced non-cohesive soil is presented. The preformed laboratory test confirmed that the inclusion of 3D printed fibres led to a significant increase in shear strength. Examination of samples after tests did not reveal breakage of fibres, thus the fibres pull-out was the governing failure mode.Fibre reinforcement is an effective method of soil improvement that presents an alternative solution to other more common methods of ground reinforcement such as mechanical stabilization by geosynthetics (geogrids, geotextiles, geocomposites, etc.). Research activities in this area are being carried out, but the main disadvantage of currently used fibres is their uniform cross-section and usually smooth surface given by available production methods. This study presents an alternative way of fabrication of synthetic fibres – utilization of fused deposition modelling (3D printing). With the rapid development in commercially available 3D printing techniques, it is now possible to refine the shape and dimensions of 3D printed objects to a tenth of a millimetre. The review of the basic index and mechanical properties of fibre-reinforced soils is presented in the first part of the paper. The second part is devoted to the description of the production process of fibres including the suitability analysis of materials used for 3D printing. Finally, the initial testing programme of fibre-reinforced non-cohesive soil is presented. The preformed laboratory test confirmed that the inclusion of 3D printed fibres led to a significant increase in shear strength. Examination of samples after tests did not reveal breakage of fibres, thus the fibres pull-out was the governing failure mode.