Issue 53

R. M. Reda et al., Frattura ed Integrità Strutturale, 53 (2020) 106-123; DOI: 10.3221/IGF-ESIS.53.09

R ESULTS AND DISCUSSION

T

he key points of the load–deflection curves obtained from the FE analysis; such as cracking load P cr , yield load P y , yield deflection Δ y ultimate load P u and maximum deflection Δ u , percentage of increase in maximum load carrying capacity for strengthened beams with respect to CB P u %, in addition to ductility index μ (the ratio of the ultimate deflection to the deflection at yielding), stiffness E , energy absorption Ω (the area under load–deflection curve) and also failure mode of the strengthened beams were presented in Tab. 2. The control beam failed due to concrete crushing after yielding of the steel reinforcement, while beams 1G-0.25/S, 2G-0.5-45/150, 2G-0.5-60/100 and 2G-0.25-90/150 for example failed due to epoxy debonding as shown in (Fig. 7) which mean that the developed FE model is capable of predicting the epoxy-concrete interface debonding failure.

P cr (kN) 27.5

P y (kN)

P u (kN) 90.55 122.9 119.7

E (kN/mm)

Δ y (mm)

Δ u (mm)

Ω (kN.mm) Failure mode

P u %

Beam ID

μ

CB

85 94 92 91

4.3 4.2 4.2 4.5 4.5 4.6 4.2 3.6 4.3 4.6 0.4 4.4 4.1 4.1 4.6 4.1 4.2 4.9 3.7 4.3 4.1 3.9 4.4 4.6 4.8 4.8 4.7 4.6 4.2 4.1 4 4 4

21

-

4.9 3.5 2.6 6.7 3.0 2.2 4.6 6.4 3.8 3.7 6.1 4.0 5.1 7.0 5.2 6.0 4.5 7.0 5.1 3.4 4.6 6.8 3.4 4.7 5.3 5.1 6.9 7.0 7.1 5.0 6.2 5.0 5.4

65.8 65.9 65.9 66.0 66.1 66.2 66.2 70.8 69.0 68.9 68.9 68.9 68.8 68.9 68.7 68.9 70.3 70.1 70.1 70.1 70.1 71.5 68.8 70.1 70.0 70.1 70.0 70.4 70.2 69.9 69.9 70.2 70.0 70.1

1706

CC

1G-0.8-S 1G-0.5-S 1G-0.25-S 2G-0.8-S 2G-0.5-S 2G-0.25-S

33 32 28 32 33 31 29 29 29 29 29 29 29 29 33 31 36 31 31 31 34 31 31 31 30 37 29 29 36 30 30 33

14.7

35.7 32.2

1403.1

CCS CCS

11 30

953

94.7

4.6

2636.4 1492.4

EED-CCS

106 105

154.1 129.9

13.6 10.1 19.4

70.2 43.5

EC

941.9 1664

EED CCS

35.5

90 93

96.4

6.5

1G-0.8-45/50 1G-0.5-45/50 1G-0.25-45/50 1G-0.8-45/100 1G-0.5-45/100 1G-0.25-45/100 1G-0.8-45/150 1G-0.5-45/150 1G-0.25-45/150 2G-0.8-45/50 2G-0.5-45/50 2G-0.25-45/50 2G-0.8-45/100 2G-0.5-45/100 2G-0.25-45/100 2G-0.8-45/150 2G-0.5-45/150 2G-0.25-45/150 1G-0.8-60/50 1G-0.5-60/50 1G-0.25-60/50 1G-0.8-60/100 1G-0.5-60/100 1G-0.25-60/100 1G-0.8-60/150 1G-0.5-60/150 1G-0.25-60/150

153.6

23.15

69.6 58.1 42.0 60.8 63.1 43.9 66.2 66.5 53.6 99.7 90.1 67.9 96.9 79.5 55.8 94.6 84.3 62.2 66.6 66.3 54.1 76.5 77.4 49.1 70.7 61.5 50.9

2796.8 1797.7 1790.5 2158.1 3517.2 1864.4 2474.2 3606.5 2724.2 3440.1 2393.9 3664.9 3563.1 1428.7 2241.2 3801.5 1688.9 2105.2 2817.6 3966.5 4403.5 4382.5 2152.1 2837

CC

102 103

143.14 128.58 145.6 147.7 130.3 150.5 150.8 139.1 180.8 162.5 141.1 176.2 166.9 146.9 150.9 150.6 139.5 159.8 160.6 154.6 146.2 136.6 172.15 152 178.28 135

16.189

CCS EED CCS

17.17

98

18.8 28.2 17.7 20.9 28.5

47.0

105 101

4.65

CC

CCS-EC

99 99

EC CC

103 104 104 103 117 101 103 101 105 100 101 104 103 107 104

24.01 24.11 18.37

EED CCS CCS

29.3 24.8 12.5 19.7 27.2 18.3 23.2 23.4 33.2 33.4 14

EC CC

CCS

CC CC

EED

EC CC

CCS EED IED

33.46 19.88

CC

95

CCS

105 101

28.6 20.9 22.2

3661

CC

2481.9 2478.7

CCS EED

96

114