Manufacturing and evaluation of structural products with recycled polymers

The rapid growth of Wastes from Electrical and Electronic Equipment (WEEE) can be attributed to the rapid developments in technology, leading to reduction in service life to less than 2 years in certain products. Thermoplastics such as Acrylonitrile-Butadiene-Styrene (ABS) and Polycarbonate (PC) form a significant percent of the Electronic Shredder Residue (ESR) that were used in this research to manufacture and evaluate structural products with recycled polymers.;In this research, offset blocks for highway and bridge guardrail systems were developed using recycled polymers reinforced with glass fabric as shell and discarded tire strips/wood as core materials. Optimum compression molding process parameters for typical manufacturing core block modules (12.5" x 4.5" x 2") were 20 minutes of preheating followed by 15 tons of load application at 450°F for about 15 minutes, however, prototype offset block were preheated for about 30 minutes at 450°F followed by applying 30 tons of load for about 30 minutes at the same temperature. These blocks were successfully manufactured and installed near the Star city bridge, Morgantown, WV in 2004 and found to be in excellent shape after 8 months of installation based on visual inspection.;In order to evaluate mechanical properties of recycled polymers (ABS) used to manufacture offset blocks, coupon specimens were manufactured conforming to ASTM standards, with and without glass fabrics and tested in compression, tension, bending, and impact. A limited comparison was made with vinyl ester (thermoset) specimens with and without glass fabric and with specimens cut from a field-installed wooden offset block.;Use of chopped fibers reduced its impact resistance while use of continuous fabric increased the impact resistance of pure ABS whereas use of continuous fibers increased the impact resistance of pure ABS. ABS specimens with continuous fabric (bi-directional fibers) showed higher impact strength than the specimens cut from a field installed wooden offset block.;In order to study heat propagation in thermoplastics (ABS) during processing, a sliced section of a guardrail-offset block manufactured at CFC-WVU was tested for its heat conduction properties using infrared thermography. A finite element model was created to represent the manufactured specimen and analyzed under the effect of thermal loading. Results from FEM and thermography support the amount of time used to manufacture offset blocks.;Additional composite products like angle plates and dowel bars were manufactured using recycled ABS and their properties were evaluated under 3-point bending test. Optimum process temperature and pressure were suggested for laboratory manufacture.;Use of recycled polymer resins (thermoplastic ABS) for manufacturing structural/non-structural composite products and their mechanical property evaluation indicate significant potential for wide range of applications. Finally, recommendations based on this research and suggestions for future research have been provided.

Topic: Transportation Safety and Impact Analysis
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences