Carbon Laminate Properties
Based on an experimental research reported in ACI structural journal, the following results for use of FRP laminates can be drawn:
- The use of FRP laminates in strengthening concrete beams reduces deflections and increases load carrying capacity in the beams. Cracks that do occur are smaller and more evenly distributed. Furthermore, the use of FRP vertical layers can help to further reduce deflections and to further increase ultimate load carrying capacity. The presence of vertical layers also prevents rupture in the flexural (horizontal) strengthening fibers.
- The ultimate load carrying capacity of beams can be doubled by using a proper combination of horizontal and vertical fibers coupled with the proper epoxy.
- Extending the vertical layers over the entire span of the beam reduces the diagonal cracks so that the longitudinal fibers are fully used and the load carrying capacity of the beams is significantly increased.
- The use of CFRP plates on the bottom and sides of the beam improves the response in comparison with using CFRP plates only at the bottom of the beam.
- All the FRP strengthened beams exhibited brittle behavior requiring a higher factor of safety in design.