Flexure Beam Test
As Rhino Carbon Fiber works on getting our products into the commercial market, it is important to develop relationships and educate employees of engineering firms and government officials. Our in-house engineer previously worked 13 years on projects with the Ohio Department of Transportation, City of Columbus, AEP, and multiple engineering firms with his main focus on Bridge Projects. In bridge construction, due to schedule restraints and the fast paced nature of the work, beam flexure tests are used quite often to verify that newly poured concrete has reached sufficient strength to support the necessary construction loads prior to reaching the standard 7 day cure.
Rhino obtained a beam from a local project that had been broken twice and pulled it back together with a ratchet strap. The beam was then laminated with Rhino’s 200 GSM unidirectional carbon fiber. Once the epoxy was fully cured, Rhino met with ODOT to perform the same flexural test on the beam that had broken it previously. The flexural test was performed with the load at the location of the prior break and taken up to 650 psi, the strength required to proceed with loading newly poured concrete on ODOT projects. The concrete had gained strength but this strength gain was irrelevant because the beam was already broken.
The test was then taken up to around 935 psi and still did not break. This test was performed over both of the prior breaks and the carbon fiber did not fail. This test illustrates the usefulness of carbon fiber in repairs and also in strengthening.
Since the concrete was already broken at the test locations, the flexural resistance observed was solely the strength of the carbon fiber and its bond to the concrete.