PSI - Issue 11

R. Capozucca et al. / Procedia Structural Integrity 11 (2018) 402–409 R. Capozucca, E. Magagnini, M.V. Vecchietti / Structural Integrity Procedia 00 (2018) 000–000

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4. Conclusions In this paper the behavior of two RC beams have been analyzed under free vibration; one of RC beams was damaged with notches and cracking by bending tests and strengthened with NSM GFRP rod. The strengthened RC beam has been subjected to free vibration tests at different degrees of damage obtained under bending test with free free ends. The main results of experimental tests are as follows: 1-the effect of damage due to notches in the concrete cover of RC beam’s intrados surface was non-relevant for variation of dynamic response; 2-free vibration of RC beam damaged by bending with cracking of concrete is influenced by the damage degree although the strengthening of RC beam with NSM GFRP rod reduces the variation of frequency values; 3- the behavior of RC beam strengthened with NSM GFRP rod under static loading until failure allows to verify availability of this technique of strengthening based on the bond of GFRP rod.

10% 15% 20% 25%

D0*-D1* D0*-D2* D0*-D3* D0*-D4*

Δf i /fD 0 * [%]

0% 5%

I

II

III

IV

mode

Fig.10. Comparison of variations (%) of frequency values at damage degrees respect undamaged degree D 0 * for B2 – modes r=1…4.

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