RECYCLED COMPOSITE MATERIAL FOR NEW STORM WATER INLET TOPS DESIGN

摘要

The Storm Water Management division of the City of Birmingham, Alabama replaces concrete storm water inlet tops at a very high rate, due to breakage and damage. The cost to the City is estimated at $600,000 per year. Continuous disrepair of inlet tops and blocked drains do not allow storm water to flow properly, resulting in streets flooding and compromising public safety. This paper proposes an alternative recycled composite material to overcome the above problem, providing a sustainable solution. The successful change to a recycled composite material for this application is expected to prevent millions of pounds of scrap composite material from being sent to landfill, only in the city of Birmingham, AL. The selected recycled polymer in this study is High-density polyethylene (HDPE). Two different reinforcement materials were investigated: 1) expanded steel mesh, and 2) Fiber Reinforced Polymer (FRP) bars. Flexural and low velocity impact tests were conducted in order to guide the decision of the best composite material to be manufactured on a full-scale size. Comparing flexural testing results against literature data for normal strength concrete shows that neat HDPE has four times higher strength than that of concrete. Low Velocity Impact (LVI) testing results yielded that the maximum impact load for neat HDPE, steel mesh reinforced HDPE, and recycled FRP bars reinforced HDPE are 16.5 KN, 19.8 KN, and 23.76 KN; respectively. While literature data reports that normal strength concrete has a maximum impact load of 13.6 KN only. In addition, ultraviolet (UV) exposure tests and water absorption tests were performed in order to determine the compatibility of the selected polymer for outdoor use. After 336 hours of UV exposure, a negligible drop in flexural strength was recorded for neat HDPE. Water absorption tests show an insignificant weight gain that is below 0.1% over the course of 900 hours.