Sand Tire Mixtures Research Articles

Numerical Investigation of Liquefaction Resistance of Buried Pipelines with Sand-Tire Mixture Using Critical State Two-Surface Plasticity Model

Numerical Investigation of Liquefaction Resistance of Buried Pipelines with Sand-Tire Mixture Using Critical State Two-Surface Plasticity Model

FEM analysis of wasted tire chip and sand as construction material for piles

The pile foundation can be easily damaged in the earthquake event and there is a need to reinforce the foundation to protect the superstructure. The aim of this study is to propose a material for pile foundation by using wasted tire chips mixed with sand (i.e. sand-tire mixture) and study its effectiveness in an earthquake incident. This idea is learned from many sand-tire mixtures investigations. Laboratory monotonic triaxial tests were conducted based on the pure Nevada sand and sand-tire mixture (i.e. volume of sand to volume of tire was 6:4 in this study) as the input parameters for the subsequent numerical simulation. The numerical simulation was based on a centrifuge experimental results, which was also validated in this study. The simulation results show that the proposed method has a good effectiveness for a pile foundation, since the reduction in terms of the bending moment acting on the pile foundation is significant. In addition, even in the earthquake incident, the pile foundation still has the lateral support contributed from the adjacent sand-tire mixture, which is able to protect the pile foundation from buckling and fractured. This pile foundation behavior is different from that supported by the pure sand (i.e. without sand-tire mixture), which has zero lateral support to the pile foundation in the earthquake incident. However, there is an optimal reinforced length for the sand-tire mixture, where the effectiveness becomes insignificant.

Influence of Adding Tire Chips on the Mechanical Behavior of Calcareous Sands

Scrap Tire disposal has been a critical environmental problem in many urban cities due to the enormous boost in the number of vehicles. This problem can be somehow mitigated by finding applications for these unusable materials in engineering. For instance, Scrap Tire can be executed as lightweight materials for backfill in geotechnical engineering projects. The Scrap Tire reuse in Sand-Tire Mixtures can effectively address growing environmental concerns and, at the same time, provide solutions for geotechnical problems associated with the low shear strength of the soil which fundamentally is determined as the main characteristics of Calcareous (or Carbonate) soils. In order to deeply understand the mechanical behavior of Sand-Tire Mixtures, a series of Consolidated Drained Triaxial Test were conducted in this study employing specimens with two different relative densities (i.e. 30% and 60%) under the specific confining pressures (i.e.100, 350, and 600 kN/m2). The results revealed that by adding 10% Scrap Tire into the Sand-Tire Mixtures, the loose specimen’s shear strength increases from 6 to 14% in comparison to pure sand. Furthermore, the particle breakage factor of the mixtures is considerably less than that of pure specimens.

An experimental investigation of the response of slender protective structures to rockfall impacts

This article investigates the mechanical response of slender rockfall protection embankments subjected to impacts based on real-scale experiments. More specifically, it deals with rectangular (in cross-section) vertical-sided gabion structures, designed to meet footprint constraints. These three-layered structures, 3 m in width and 4 m in height, are made up of gabion cages filled with different materials, depending on their location in the structure. Real-scale experiments were conducted with impact energies up to about 2000 kJ on two structures differing by the fill material used for their middle layer: ballast or sand–tire mixture. The experiments demonstrate the capacity of these slender structures in resisting high-energy impacts. The response of the structures is also addressed considering data obtained using different measuring techniques and a large number of sensors within the structure. The results are presented and discussed with the aim of highlighting some issues associated with the structure impact response, such as the load lateral diffusion, stone breakage, the contribution of the wire mesh, and the fill material characteristics. In the end, a structure with a middle layer filled with ballast appears more efficient in reducing the structure back face displacement.

Three-dimensional numerical simulation of mechanical properties of soil-tire mixture by discrete element method

Soil engineering properties can be improved employing different methods. Among them is mixing soil with tire derived additives (TDA). TDAs generally increase some parameters of mixture such as damping ratio, permeability, ductility and also in some cases shear strength. Various properties of TDAs from mechanical properties to their geometry can affect the mixture behavior. In this paper using the YADE platform, simulations of triaxial tests on sand tire mixtures are presented. To take compressibility into consideration, each rubber crumb particle is made of several spheres connected elastically to each other. For sand particle generation the clump technique was employed. Shapes of both sand and rubber particles are inspired from real grains. As properties of sand and rubber are different, especially Young modulus, rubber sand interaction is considered as soft rigid contact. Therefor harmonic average and arithmetic average was used to compute contact Young modulus (and then stiffness). The model was validated by comparison of results of triaxial tests simulation on pure rubber sample with literature ones which both exhibited linear stress-strain curve. Then triaxial tests with different sand to rubber ratio were simulated to see whether harmonic average or arithmetic average gives the best match to literature. The results show shear strength reduces by decreasing of sand to rubber ratio. This is the same as what is reported in literature.