Vulnerability Reduction of Bridge Piers Susceptible to Impact using a Prefabricated Polypropylene Wrap

摘要

The research focused on the effects of low velocity impact loading on high strength concrete confined by a prefabricated polypropylene jacket and comparing the results with similar specimens confined by carbon fiber. In order to accomplish this, both static and dynamic load tests were performed. Concrete cylinders were used for static loading. Twelve concrete cylinders were prepared for static load testing: three were plain concrete and used as control specimens, three were wrapped with one layer of unidirectional carbon fiber, and six were confined by the polypropylene pipe. The thickness of the polypropylene wrap was machined to different thicknesses; three 3 mm and three 6 mm. The cylinders were standard 152 mm x 305 mm. Cylinders were loaded to failure in uniaxial compression using a Tinius-Olsen Universal Testing Machine. Impact testing was performed using four 152 mm x 914 mm columns. The columns consisted of one control sample; one carbon fiber wrapped, and two (one of each thickness) wrapped with polypropylene. Impact testing was conducted using an Instron drop-tower testing machine.