Strengthening of Concrete Column Stubs through Resin Infused Composite Wraps

There is a critical need for the development and implementation of appro priate technologies to strengthen, repair and rehabilitate the infrastructure. FHWA studies estimate that the U.S. currently faces a $167 billion cost to repair deficient bridges and roads. In many cases, retrofit and rehabilitation by conventional means is very costly (due to both specialized equipment needs and closure of the structure during repair), if not im possible (e.g., the additional dead load resulting from repair of a deck/beam could very well further damage the structure and cause its final failure). Due to their inherent light ness, placement flexibility and resistance to corrosion, composites are logical substitutes for steel structural elements often used for the rehabilitation of bridge decks and columns. In this article, we focus on columnar structures where retrofit is needed to strengthen and increase compressive load carrying capacity. The use of a novel resin infusion technique is shown to contribute to substantial improvements in composite wrap efficiency. The use of 24 oz. woven glass roving as the reinforcement in the composite wrap is shown to substantially increase both load carrying capacity and deformation capability of the stubs. It is shown that through the use of glass/carbon hybrids, replication of the initial behavior of concrete is possible, along with a simultaneous improvement in load-carrying capacity (by 72 70%) and the creation of substantial increase in deformation capacity before failure.