The as built specimen is 24" in diameter and fully reinforced. It was cyclically loaded in double curvature, with an axial load, to investigate the shear and ductility enhancement provided by the Fiber-Bond™ system. The column failed at a load of 100 Kips and a deflection of 0.7". As can be seen in the photographs the damage was extensive. Much spalling was visible and the steel had yielded.

The column was then repaired as per Edge Structural Composites specifications. All loose and broken concrete was removed and all cracks filled by epoxy injection. The spalled areas were filled with a repair mortar and smoothed out in preparation for laminating. After priming and minor filling, the column was wrapped with four layers of Fiber-Bond™ carbon fiber (CFRP) to a total thickness of less than 0.10", and allowed to cure for 7 days.

The retest was again, as per Caltrans and ICBO requirements, cyclic, double curvature, the results however were dramatically different. The column easily reached 100 Kips with a deflection of 0.5". At 1" deflection, the load was 135 Kips. At this point the test was considered a success and was then continued increasing the deflection in increments of 1" for each cycle. The repaired column was finishing it's second cycle at 5" of deflection when the test fixture failed, leaving the column undamaged.

In summary, a severely damaged column was not only successfully repaired, but the ductility was increased by a factor of over 7 and the load increased by over 60%. This clearly demonstrates the effectiveness of the Fiber-Bond™ strengthening system to not only repair damaged or deficient structures but to greatly improve them.