| Roughly 4.6 billion tons of non-hazardous solid waste materials are produced annually in the US (Collins and Ciesielski, 1994). Domestic and industrial wastes constitute almost 600 million tons of this total. Of particular interest are the 20,700 tons of plastic waste generated each year, of which 5,900 tons constitutes packing wastes (Stryros, 1993).; One of the energy absorption devices which is currently in wide spread use along highways is the strong-post guardrail system. This system is used to contain and redirect the errant vehicle during a collision with a guardrail. In this research, a guardrail post manufactured from recycled plastic is evaluated for possible use in such a guardrail system. This study was intended to investigate specifications for recycled materials used in roadside safety applications, in particular, posts used in strong-post guardrail systems. To achieve this goal, this study comprised five distinct phases: (1) identifying recycled material manufacturers and requesting their involvement in this study; (2) performing a series of laboratory and dynamic testing to make a conclusive decision regarding the suitability for implementation for these received recycled guardrail posts; (3) carrying out full-scale crash tests on promising posts to validate laboratory results and verify their crashworthiness; (4) utilizing analytical tools in conjunction with full-scale crash tests to improve the performance of guardrail system; and (5) preparing recommended specifications for recycled content guardrail posts. A state-of-the-art finite element program, LS-DYNA3D, was selected as the analytical platform.; As a results of this study, it was determined that the available recycled post products showed a wide range of behavior due to different material compositions, steel reinforced plastics, commingled plastics, etc. Stiffnesses were much lower and the tendency to creep was much greater compared to wood. However, a number of products displayed satisfactory performances. It was also determined that mechanical properties of plastics are highly dependent on temperature. The performance of recycled posts was determined to be unacceptable since strength and stiffness of recycled plastic posts decreased with increasing temperature at a greater rate than wood. |
