Rubber Grains Research Articles

Structural relaxation and morphology of the rubber-urethane composites

The supermolecular structures and structural relaxation of the waste rubber–urethane composites are discussed on the basis of results of calorimetric measurements and mechanical spectroscopy. The results give a broader understanding of the relationship between processing history and morphology in the resultant engineering products. The effect of different kinds of urethane prepolymer on the thermomechanical properties of commercial composite products is presented. The idea of reaction between rubber granulate and urethane prepolymer is under consideration. The shear and tensile modes were applied to better explore relaxations that occur in rubber grains and in an interphase area created by the urethane agents. The rubber waste management problem was taken into account also. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1186–1193, 2004

Shear strength characteristics of sand-mixed with granular rubber

Waste materials such as waste tires, rubbers, and plastic materials are normally produced in every society, entering the environment and causing serious problems. These problems may be somehow reduced by finding applications for them in engineering, for example, as lightweight materials for backfill in geotechnical projects. To this aim, this paper demonstrates how shear strength characteristics of sand mixed with various percentages of waste garden hose grains are altered. A relatively, uniform sand has been mixed with waste hose grains in loose and slightly compacted states. Waste hose grains were prepared with special popular machinery in a local area. Various sand-rubber mixtures having 0%, 10%, 15%, 20%, 50%, 70%, and 100% waste hose particles by weight were chosen. The rubber grains were distributed in the sand such that uniform mixtures are obtained. In order to compare the shear strength of different sand-rubber samples, two compaction states were considered. The results show that the influencing parameters on shear strength characteristics of sand-rubber mixtures are normal stress, mixture unit weight, and rubber content. With the selected waste hose particles, compaction states, and rubber contents, the initial friction angle φ1 does not change significantly. However, an apparent cohesion appears in the mixtures. From environmental point of view and due to lightweight material for the sand-waste hose particles, it may be useful to use such materials in corresponding geotechnical projects.

Compression Tests on Scrap Tire Rubber Grains for their use as Lightweight Geomaterials

Compression Tests on Scrap Tire Rubber Grains for their use as Lightweight Geomaterials

Transport properties of disordered continuum systems.

We show that random-walk simulations are particularly well suited to the description of transport in continuum systems. This approach is illustrated with calculations on consolidated multisize granular materials where our results are in excellent agreement with experimental data on sintered binary composites. We also present the first detailed calculations on anisotropic packings. Here, our calculations are in good agreement with the results of electrical measurements on brine-saturated spherical rubber grains under uniaxial pressure.