This Small Business Innovation Research (SBIR) Phase I project will develop: connections between concrete-filled fiber reinforced polymer (FRP) tubes (splicing and joints) and with other traditional construction materials; a cost-effective structural framing system; and design aids and specifications for these structural framing systems. The advantages of concrete-filled FRP tubes (CFFT) over concrete-filled steel tubes (CFST) include high strength-to-weight ratio, durability, and the possibility of optimizing and engineering the fiber orientation for best result. Experiments have shown that CFFTs can significantly increase strength and ductility of normal strength concrete (3-5 thousand pounds per square inch (ksi) and 0.003-0.004 ultimate strain) to the level of high-performance concrete (15-20 ksi and 0.02-0.04 ultimate strain). Phase I will develop both analytical and experimental components, conduct modeling, calibration, and parametric studies, and perform limited proof-of-concept testing. Phase II would concentrate on manufacturing these new system components. The new framing system utilizing CFFTs and other structural forms are expected to be used in civil construction such as buildings and bridges. It will offer superior seismic performance and higher resistance to explosion damage, such as in terrorist attacks, in comparison with traditional systems. In addition, long durability and corrosion resistance are expected to extend the designed life span of many civil structures with low maintenance costs
