Issue 38

I. N. Shardakov et alii, Frattura ed Integrità Strutturale, 38 (2016) 331-338; DOI: 10.3221/IGF-ESIS.38.43 335 Specimen Concrete class M crc , kNm Rebound deflection, mm M ult , kNm f ult , mm a crc,max , mm ε f,ult , με Debonding type Specimen failure behavior Bla-1 B25 3.81 0.183 6.13 9.50 2.7 - - RR* Bla-2 B25 3.91 - 7.45 19.84 2.0 - - RR+CCC Bla-3 B25 4.27 6.92 21.43 2.0 - - RR*+CCC Mean value 4.00 0.183 6.83 - 2.2 - - - B1b-1 B25 4.28 - 10.05 14.29 1.1 12170 mixture FRPR* Blb-2 B25 5.07 - 10.42 11.16 0.5 11170 mixture FRPR* Blb-3 B20 4.33 0.206 10.25 8.30 1.0 13370 cohesion FRPR Blb-4 B30 5.40 0.257 10.10 8.08 0.9 12180 cohesion. FRPR Blb-5 B20 4.32 0.218 11.07 9.78 1.1 15040 cohesion. FRPR Mean (adhesive) - 4.68 - 10.24 12.72 0.9 11670 - Mean (cohesive) - 0.227 10.47 8.72 13530 - B2a-1 B35 4.74 - 6.98 10.60 1.5 - RR* B2a-2 B35 5.15 - 6.98 15.75 7.0 - RR+CCC B2a-3 B40 4.98 0.221 7.39 19.73 3.0 - RR*+CCC Mean value 4.96 0.221 7.12 - 2.2 - - B2b-1 B35 6.14 - 10.03 10.37 0.8 12180 mixture. FRPR* B2b-2 B40 5.79 - 10.19 12.52 1.6 10860 adhesion FRPR* B2b-3 B40 5.49 0.260 10.56 8.92 1.1 13790 cohesion. FRPR B2b-4 B40 5.09 0.213 11.46 9.31 1.0 14280 cohesion. FRPR B2b-5 B40 5.43 0.252 10.27 8.06 1.3 12190 cohesion. FRPR Mean (adhesive) - 5.59 - 10.11 11.44 1.1 11520 - - Mean (cohesive) - 0.242 10.76 8.76 13420 - - Notes: RR reinforcement rupture, CCC - crushing of compressive concrete, RR* - reinforcement rupture sectional weakened spot welding, FRPR - midspan FRP rupture, FRPR* - FRP rupture sectional strap anchorage, mix. - mixed debonding, coh. - cohesive debonding, adh. - adhesive debonding Table 1 : The results of static test of beams of series A and B. Speci- men Con- crete class Loading before the appearance of the first cracks Bending moment during reinforce- ment, kNm Loading after the appearance of the first cracks and their grouting Debond- ing type Specimen failure behavior M crc , kNm Rebound deflection, mm Maximum bending moment, kNm a crc,max , mm M crc , kNm M ult , mm f ult , mm a crc,max , mm ε f,ult , με Blc-1 B20 3.32 0.142 5.15 1.0 4.30 6.79 10.39 10.80 1.4 11680 cohes. FRPR Blc-2 B20 3.60 0.164 5.23 1.5 4.81 7.19 8.75 9.19 1.5 10190 cohes. FRPR Blc-3 B30 3.86 0.186 5.20 1.0 4.59 6.59 10.19 11.07 1.3 12760 cohes. FRPR Mean value - 3.60 - 5.19 1.2 4.57 6.86 10.29 - 1.4 11540 - - B2c-1 B40 4.30 0.179 5.49 1.0 4.56 6.88 1137 10.29 1.1 14180 cohes. FRPR B2c-2 B40 4.92 0.214 5.64 0.9 4.79 7.02 9.03 9.75 1 8655 cohes. RR*+ FRPR B2c-3 B40 5.19 0.202 5.52 1.0 4.58 7.69 10.62 10.72 1.3 12430 cohes. FRPR Mean value - 4.80 - 5.55 1.0 4.64 7.19 11.00 - 1.1 13305 - - Table 2 : The results of static tests of beams of series C. The evolution of deformation in the beams reinforced under the load is of particular interest. At the initial stage of loading such a beam behaves in the same way as a non- strengthened one (Fig. 4, solid thick lines). The