Thermal analysis of GFRP-reinforced continuous concrete decks subjected to top fire

Open Access
Original Research

Abstract

This paper presents a numerical study that investigates the behavior of continuous concrete decks doubly reinforced with top and bottom glass fiber reinforced polymer (GFRP) bars subjected to top surface fire. A finite element (FE) model is developed and a detailed transient thermal analysis is performed on a continuous concrete bridge deck under the effect of various fire curves. A parametric study is performed to examine the top cover thickness and the critical fire exposure curve needed to fully degrade the top GFRP bars while achieving certain fire ratings for the deck considered. Accordingly, design tables are prepared for each fire curve to guide the engineer to properly size the top concrete cover and maintain the temperature in the GFRP bars below critical design values in order to control the full top GFRP degradation. It is notable to indicate that degradation of top GFRP bars do not pose a collapse hazard but rather a serviceability concern since cracks in the negative moment region widen resulting in simply supported spans.

Keywords

Finite elements Thermal-stress analysis GFRP bars Fire simulation curves Concrete cover Design tables 

Introduction

GFRP bars have been considered and used worldwide as negative and positive reinforcement in concrete decks, such as bridge decks as shown in Fig. 1, especially in cold regions to resist the corrosion imposed on conventional steel bars by the frequent use of high dosage of deicing salts leading to fast deterioration of bridge decks due to the ingress of chlorides (Koch and Karst 2013).
Fig. 1

GFRP bars used for negative and positive reinforcement in bridge decks, Courtesy of Hughes Brothers

The problem of studying fire resiliency in reinforced concrete (RC) beams strengthened with CFRP composites and subjected to bottom and top fire has been addressed numerically by the authors and co-workers (Hawileh et al. 2009, 2011; Naser et al. 2014, 2015). These numerical studies were benchmarked against several experimental investigations related to the same subject (Blontrock et al. 1999; Williams et al. 2006; Tan and Zhou 2011). This problem was extended to investigate the high-temperature effects in bridge decks externally strengthened with FRP when subjected to accidental events like top fire or maintenance activities like surfacing with bituminous paving materials (Del Prete et al. 2015).

The behavior of concrete beams reinforced with GFRP bars under fire is experimentally investigated by Abbasi and Hogg (2006). The first author and a co-worker (Hawileh and Naser 2012) developed a three-dimensional finite element (FE) model that predicted with a good level of accuracy the fire resistance of a beam reinforced with glass (GFRP) bars that was tested by Abbasi and Hogg (2006). The validated model was utilized in a design oriented parametric study to examine the effect of the bottom concrete cover thickness and different fire scenarios on the fire resistance of beams reinforced in flexure with GFRP bars. Yu and Kodur (2013) studied the same problem numerically to identify factors affecting the fire response of concrete beams reinforced with FRP bars. The two papers reported that the rebar type, concrete cover thickness, and the fire scenario are the key parameters affecting fire endurance.

The behavior of concrete slabs reinforced with FRP bars or grids, in concrete buildings subjected to fire loading, is addressed experimentally and numerically in a two-part paper (Nigro et al. 2011a, b). Shortly after that, the same research group published a paper proposing guidelines for the flexural resistance of concrete beams and slabs subjected to fire in accordance to Eurocode2 (2004) guidelines.

In this study, a numerical investigation is performed to examine continuous concrete decks doubly reinforced with top and bottom glass fiber reinforced polymer (GFRP) bars subjected to top surface fire. A detailed transient thermal FE analysis is carried out under the effect of various fire curves. A parametric study is performed to examine the top cover thickness and the critical fire exposure curve needed to fully degrade the top GFRP bars while achieving certain fire ratings for the bridge deck considered.

Approach of numerical analysis

In order to perform transient thermal FE analysis on a continuous concrete deck subjected to top surface fire loading, a three-dimensional FE model for a segment of a typical concrete bridge deck without surfacing materials (like bituminous) taken at an interior support is modeled and analyzed as follows:
  1. 1.

    Develop a FE model of the concrete deck reinforced with top and bottom GFRP bars using thermal brick and link elements for the concrete and GFRP bars, respectively.

     
  2. 2.

    Vary the input data for the thermal material properties of the concrete deck as a function of temperature according to Eurocode2 (2004) guidelines.

     
  3. 3.

    Apply a temperature versus time curve to the top surface of the concrete deck and perform transient thermal analysis to simulate the heat transfer throughout the deck by conduction, convection, and radiation due to the applied fire curve scenario.

     
  4. 4.

    The needed output of the thermal analysis is the progression of temperature along the top GFRP bars for the entire fire exposure.

     

It should be noted that the authors analyzed one way slab for FE modeling in this study. However, the progressions of temperature in the top GFRP bars are also applicable to two-way slabs. The top concrete cover is measured from the top concrete surface to the center of the top GFRP bars layer.

FE model description

Geometry and material properties

Figure 2 shows the developed FE model for a typical segment of a bridge concrete deck at an interior support, having a width and thickness of 1000 and 250 mm, respectively. The model is created and analyzed using the finite element software ANSYS-Release Version (2013). The deck is reinforced with top and bottom GFRP bars. The negative moment at the interior support is resisted by 9 #25 (Area = 510 mm2 per bar, total area = 4590 mm2) diameter GFRP bars located with a typical top cover thickness of 25 mm as shown in Fig. 2. It should be noted that the top cover thickness measured from the top concrete surface to the center of the top GFRP bars is one of the parameters that will be varied in this study to examine its effect on the fire resistance of bridge decks when subjected to top fire loading. The deck is also reinforced with 6 #25 (Area = 510 mm2 per bar, total area = 3060 mm2) diameter GFRP bars with a bottom concrete cover of 25 mm. The center-to center spacing between the bars located at the top and bottom of the deck is 100 and 150 mm, respectively.
Fig. 2

Developed FE model of a concrete deck

The brick SOLID70 and spar LINK33 thermal elements (ANSYS-Release Version 2013) are used to model the concrete and GFRP bars, respectively. The thermal brick SOLID70 element has a total of eight nodes with a temperature degree of freedom (dof) at each node (ANSYS-Release Version 2013). The thermal spar LINK33 element (ANSYS-Release Version 2013) is a three-dimensional uniaxial element defined by two nodes and has a temperature dof per node. Both elements have the capability of transferring heat in a transient thermal analysis throughout the deck due to applied fire that will be initiated in this study at the top surface of the concrete deck.

The temperature-dependent thermal conductivity, specific heat, and density are required input material properties to perform transient thermal analysis. The temperature-dependent input thermal properties of the concrete material in the developed FE model are based on Eurocode2 (2004) guidelines. The concrete slab is conservatively assumed to be made of siliceous aggregates and cast with a moisture content of 3%, by weight. Figures 3, 4, and 5 show the variation of the thermal conductivity, specific heat, and density with temperature for the concrete deck. The thermal conductivity, specific heat, and density of the GFRP bars were taken at room temperature as 4.0 × 10−5 W/mm K, 1310 J/kg K, and 1600 kg/m3, respectively (Hawileh and Naser 2012).
Fig. 3

Thermal conductivity of concrete as a function of temperature (Eurocode2 2004)

Fig. 4

Specific heat of concrete as a function of temperature (Eurocode2 2004)

Fig. 5

Density of concrete as a function of temperature (Eurocode2 2004)

Top fire scenarios

The top surface of the concrete deck will be subjected to different fire exposure scenarios in the form of temperature versus time curves with a convective heat transfer coefficient of 20 W/m2K. The model also accounts for heat transfer by radiation using a Stefan–Boltzman radiation coefficient and concrete emissivity constants of 5.669 × 10−8 W/m2K4 and 0.7, respectively (Del Prete et al. 2015). A transient thermal analysis is performed for every fire exposure with several time load steps and substeps. The temperature distribution throughout the deck and progression of temperature throughout the GFRP bars are the main output of the thermal analysis. The output of the transient thermal analyses includes temperature distribution throughout the slab specimen for the entire fire exposure.

Figure 6 shows the heat loading fire scenarios which include the standard building fire curve ASTM Test Method E119 (2002) which is quite similar to ISO834 (1975) fire curve, ASTM E1529 (1993) hydrocarbon fire curve, hydrocarbon modified curve (HMC), RWS fire curve that is usually used to simulate possible fire in tunnels, RABT_Train and RABT_Car fire curves (2008).
Fig. 6

Applied top surface fire scenarios

The hydrocarbon ASTM E1529 (1993) and HCM fires (2008) represent possible fire scenarios from petrochemicals such as fire from car fuel tanks, gasoline and oil tankers. It should be noted from Fig. 6 that HCM fire curve is more severe than that of the ASTM E1529 where the temperature can reach 1300 °C instead of 1100 °C for the ASTM E1529 fire curve. The road tunnel RWS fire curve (Fehérvári 2008) was developed by the Ministry of Transport in the Netherlands and represents a fire lasting up to 120 min of a 50-m3 fuel, oil or petrol tanker with a fire load of 300 MW. The RABT fire curves (train and car) shown in Fig. 6 were developed in Germany (2008) with shorter fire exposure compared to other scenarios and a very rapid temperature rise up to 1200 °C within 5 min. As shown in Fig. 6, the temperature drop for RABT_Train and RABT_Car started to occur after 60 and 30 min of fire exposure, respectively.

Fire resistance

In this study, the fire resistance of the concrete deck due to the applied top fire exposure is assumed to occur when the temperature of the GFRP bars reaches a specified critical temperature (fire rating). The ACI 440.1R-15 (2015) guidelines did not specify a critical temperature for GFRP bars since there is a lot of debate about it that still warrants further research investigations. The reported critical temperature ranges from 65 °C to about 350 °C (ACI 440 1R 2015). In this study, the time to failure (fire resistance) for the entire range (65–350 °C) will be reported for the investigated fire case scenarios shown in Fig. 6.

Results and discussions

Validation model

As mentioned earlier, the first author and a co-worker (Hawileh and Naser 2012) developed a FE model that was capable of predicting the fire resistance of simply supported concrete beams reinforced in flexure with GFRP bars and subjected to ISO834 bottom fire exposure. The numerical results were in close agreement with that of the experimental results conducted by Abbasi and Hogg (2006). A comparison between the predicted and measured progression of temperature in the GFRP bars is shown in Fig. 7.
Fig. 7

Measured and predicted temperature in the GFRP bars (Hawileh and Naser 2012)

It clearly indicated from Fig. 7 that there is a close agreement between the measured and predicted temperature at all stages of fire loading. In addition, the authors (Hawileh and Naser 2012) predicted with a high level of accuracy the mid-span deflection response results for the entire fire exposure. It should be also noted that the authors developed in a previous study (Hawileh et al. 2009) a FE model that simulated the thermal and mechanical response of reinforced concrete beams externally strengthened with CFRP laminates subjected to fire loading. The predicted and recorded temperatures at different depths of the beam’s cross-section were in close agreement (Hawileh et al. 2009). Thus, the developed FE model in this study can predict with a good level of accuracy the temperature distribution in the RC slab during the entire fire exposure.

It should be noted that the literature is lacking data on the fire resistance of continuous concrete bridge decks when subjected to top fire loading. Thus, it could be confidently extrapolated that the developed FE model can predict with a reasonable level of accuracy the fire resistance of concrete bridge decks when subjected to top fire loading.

Fire resistance of concrete deck under top fire loading

A total of 60 cases are analyzed to examine the effect of top concrete cover on the fire resistance of concrete decks reinforced with GFRP bars and subjected to the six different fire curve scenarios discussed in the preceding section. The fire loading in the form of temperature versus time curves is applied to the top surface of the concrete deck. The top concrete cover is varied from 25 to 70 mm with an increment increase of 5 mm. This will examine the effect of top concrete cover thickness and different possible fire scenarios on the fire resistance of concrete bridge decks when subjected to top fire loading.

Figures 8, 9, 10, 11, 12, and 13 show the progression of temperature in the top GFRP bars due to the applied ASTM E119, ASTM E1529, HMC, RWS, RABT_Train, and RABT_Car fire scenarios respectively.
Fig. 8

Progression of temperature in the top GFRP bars due to ASTM E119 fire exposure

Fig. 9

Progression of temperature in the top GFRP bars due to ASTM E1529 fire exposure

Fig. 10

Progression of temperature in the top GFRP bars due to HCM fire exposure

Fig. 11

Progression of temperature in the top GFRP bars due to RWS fire exposure

Fig. 12

Progression of temperature in the top GFRP bars due to RABT_Train fire exposure

Fig. 13

Progression of temperature in the top GFRP bars due to RABT_Car fire exposure

Figures 8, 9, 10, 11, 12, and 13 display the results for top concrete cover of 25, 30, 35, 40, 45, 50, 55, 60, 65, and 70 mm, respectively. As expected, it is clearly indicated in Figs. 8, 9, 10, 11, 12, and 13 that as the top concrete cover thickness increases, the temperature in the GFRP bars decreases which would thus lead to an increase in the time for the GFRP bars to reach their critical specified temperature limit. In addition, the plotted results in Figs. 8, 9, 10, 11, 12, and 13 indicate that the ultimate temperature attained in the top GFRP bars is higher for the modified hydrocarbon HMC fire curve than that for the other five studied fire exposures. It should be noted that the increase of temperature in the GFRP bars would lead to a reduction in the elastic modulus and tensile strength of the top GFRP bars. However, the degradation in the mechanical properties of the top GFRP bars do not cause a collapse of the concrete deck but rather a serviceability concern since cracks in the negative moment region of continuous spans widen resulting effectively in adjacent simply supported spans. It should be also noted from Figs. 12 and 13 that there is a recovery (reduction) in the progression of temperature in the top GFRP bars for the two slabs subjected to RABT_Train and RABT_Car fire exposure, respectively. This recovery is caused by the presence of the cooling phase in the applied RABT_Train and RABT_Car fire curves as shown in Fig. 6.

Tables 1, 2, 3, 4, 5, and 6 provide the results for the fire resistance of concrete decks when subjected to the six different top fire loading scenarios. The fire resistance is defined in this study as the time for the top GFRP bars to reach a critical specified temperature, which in turn referred to fire rating of the concrete deck. Since the critical temperature limit in the GFRP bars is still debatable and ranges between 65 and 350 °C, the time to failure is reported in Tables 1, 2, 3, 4, 5, and 6 for the critical temperature values of GFRP bars of 65, 80, 100, 125, 150, 180, 200, 250, 300, and 350 °C, respectively. For example, the fire resistance for a concrete deck with a 25-mm top cover and subjected to ASTM E119, ASTM E1529, HMC, RWS, RABT_Train, and RABT_Car top fire exposures is 49, 35, 33, 30, 33, and 33 min, respectively, if the critical specified temperature in the top GFRP bars is 200 °C. Similarly, if the designer is aiming to achieve a fire rating of 90 min for the concrete deck with the same type of GFRP reinforcement, a minimum top cover thickness of 55, 65, 70, 70, 65, and 60 mm is required for the ASTM E119, ASTM E1529, HMC, RWS, RABT_Train, and RABT_Car top fire exposures, respectively.
Table 1

Fire resistance (in minutes) of top GFRP bars when subjected to ASTM E119 fire

Top cover

Critical design temperature of top GFRP bars (°C)

(mm)

65

80

100

125

150

180

200

250

300

350

25

13a

17

22

28

34

43

49

66

86

110

30

16

20

25

32

39

49

55

75

99

124

35

18

23

29

36

44

55

63

84

110

139

40

21

26

33

41

50

62

70

94

122

155

45

24

30

37

46

56

69

78

105

136

171

50

27

33

41

51

62

77

87

116

150

189

55

30

37

45

57

69

85

96

127

165

206

60

33

41

50

63

76

93

105

140

180

225

65

37

45

55

68

83

102

115

152

195

>240

70

40

49

60

75

90

110

125

164

211

>240

a Fire endurance

Table 2

Fire resistance (in minutes) of top GFRP bars when subjected to ASTM E1529 fire

Top cover

Critical design temperature of top GFRP bars (°C)

(mm)

65

80

100

125

150

180

200

250

300

350

25

10a

13a

15a

19

24

30

35

47

65

84

30

12

15

18

23

28

35

40

56

75

99

35

14

18

21

26

32

41

46

65

87

114

40

16

20

24

31

38

48

54

74

99

131

45

18

23

28

35

43

54

61

84

114

149

50

21

26

32

40

49

61

69

95

126

167

55

23

29

36

44

55

68

78

106

141

186

60

26

32

40

49

61

76

87

119

158

206

65

29

36

44

55

68

84

96

130

174

228

70

32

40

49

61

75

92

105

144

192

>240

a Fire endurance

Table 3

Fire resistance (in minutes) of top GFRP bars when subjected to HCM fire

Top cover

Critical design temperature of top GFRP bars (°C)

(mm)

65

80

100

125

150

180

200

250

300

350

25

11a

14a

17

20

24

30

33

43

55

69

30

13a

16

19

24

28

34

38

49

65

81

35

15a

18

22

27

32

39

44

57

75

94

40

17

21

25

31

36

44

50

65

84

108

45

20

24

28

35

42

50

56

75

96

123

50

22

27

32

39

47

56

63

84

108

138

55

25

30

36

44

52

63

72

94

120

153

60

28

33

40

49

58

70

79

105

135

171

65

31

36

44

54

65

77

87

115

149

>180

70

34

40

48

59

70

86

96

126

162

>180

a Fire endurance

Table 4

Fire resistance (in minutes) of top GFRP bars when subjected to RWS fire

Top cover

Critical design temperature of top GFRP bars (°C)

(mm)

65

80

100

125

150

180

200

250

300

350

25

9a

11a

14a

18

21

26

30

40

52

62

30

11a

14a

17

21

25

31

35

47

60

76

35

13a

16

20

25

30

36

41

54

70

80

40

15a

19

23

28

34

42

47

62

80

102

45

17

21

26

32

39

47

53

70

91

117

50

20

24

30

37

44

54

60

79

102

135

55

23

28

34

41

49

60

67

89

116

153

60

26

31

37

46

55

67

75

99

130

171

65

29

34

42

51

61

74

83

110

146

>180

70

31

38

46

57

67

82

92

122

162

>180

a Fire endurance

Table 5

Fire resistance (in minutes) of top GFRP bars when subjected to RABT_Train fire

Top cover

Critical design temperature of top GFRP bars (°C)

(mm)

65

80

100

125

150

180

200

250

300

350

25

11a

13a

16

19

24

29

33

45

58

80

30

13a

15a

19

23

28

34

39

52

68

>120

35

15a

18

22

27

32

40

45

61

83

>120

40

17

21

25

31

36

45

52

70

105

>120

45

20

24

28

35

43

52

60

80

>120

>120

50

23

27

33

40

49

59

67

94

>120

>120

55

26

30

37

45

55

66

76

111

>120

>120

60

28

34

41

50

61

75

85

>120

>120

>120

65

31

38

46

56

67

83

95

>120

>120

>120

70

35

42

51

62

74

93

109

>120

>120

>120

a Fire endurance

Table 6

Fire resistance (in minutes) of top GFRP bars when subjected to fire

Top cover

Critical design temperature of top GFRP bars (°C)

(mm)

65

80

100

125

150

180

200

250

300

350

25

11a

13a

15a

19

23

28

33

46

79

>120

30

13a

15a

18a

23

27

34

40

57

>120

>120

35

15a

18

21

26

32

40

46

72

>120

>120

40

17

20

25

31

38

46

55

>120

>120

>120

45

20

24

29

35

43

54

63

>120

>120

>120

50

23

27

32

40

49

63

75

>120

>120

>120

55

26

30

37

45

55

72

88

>120

>120

>120

60

29

33

40

51

62

82

>120

>120

>120

>120

65

32

37

45

56

70

96

>120

>120

>120

>120

70

35

41

50

63

79

>120

>120

>120

>120

>120

a Fire endurance

Tables 1, 2, 3, 4, 5, and 6 could be used as design tables to guide engineers to properly size the top concrete cover and maintain the temperature in the GFRP bars below critical design specified values when subjected to six different possible top fire loading scenarios. Thus, properly sizing the top concrete cover would control the full degradation of the top GFRP bars during fire exposure.

Summary and conclusions

A 3D FE model was developed to conduct a detailed transient thermal analysis of continuous concrete bridge decks doubly reinforced with GFRP bars subjected to top fire loading. The model was benchmarked first against experimental results for concrete beams reinforced in flexure with GFRP bars subjected to bottom fire loading to examine the reliability of its results. After that, a parametric study was conducted to develop design tables that provide fire rating for the concrete bridge decks based on various fire curves considered and different concrete cover thickness values explored. This way, the designer can select the concrete cover thickness that gives a certain deck fire rating (certain time to failure of GFRP bars) when subjected to a specific standard fire scenario. It is important to note that the degradation in the mechanical properties of the top GFRP bars does not pose a collapse threat of the concrete deck but rather a serviceability concern since cracks in the negative moment region of continuous spans widen resulting effectively in adjacent simply supported spans that result in top surface cracks and significantly increased deflections. Based on the results of this study, the following observations and conclusions were drawn:
  • The top concrete cover thickness is the most important parameter that influences the fire resistance of concrete slabs when exposed to top fire loading.

  • As the concrete cover thickness increases, the temperature in the GFRP bars decreases. Thus, the fire ratings of the slab will increase.

  • A minimum top concrete cover thickness of 55, 65, 70, 70, 65, and 60 mm is required to achieve a fire resistance of 90 min for the ASTM E119, ASTM E1529, HMC, RWS, RABT_Train, and RABT_Car top fire exposures, respectively.

  • The most severe fire exposure scenario is the modified hydrocarbon (HMC) fire curve. Thus, the top concrete cover thickness of concrete bridge decks should be designed to achieve a specified fire resistance (for example 90 min) when exposed to the HMC fire curve.

  • A nominal concrete cover thickness of 70 mm is sufficient to preserve the GFRP bars when subjected to severe fire scenarios.

Notes

References

  1. Abbasi A, Hogg PJ (2006) Fire testing of concrete beams with fibre reinforced plastic rebar. Compos A Appl Sci Manuf 37(8):1142–1150CrossRefGoogle Scholar
  2. ACI 440 1R-15 (2015) Guide for the design and construction of structural concrete reinforced with fiber reinforced polymer (FRP) bars. Reported by ACI Committee 440. Farmington Hills, p 84Google Scholar
  3. ANSYS-Release Version 14.5 (2013). A finite element computer software and user manual for nonlinear structural analysis, Inc. CanonsburgGoogle Scholar
  4. ASTM Test Method (1993) E1529 Standard test methods for determining effects of large hydrocarbon pool fires on structural members and assemblies. American Society for testing and materials, West ConshohockenGoogle Scholar
  5. ASTM Test Method E119 (2002). Standard test methods for fire tests of building construction and materials. American Society for testing and materials, West ConshohockenGoogle Scholar
  6. Blontrock H, Taerwe L, Matthys S (1999) Properties of fiber reinforced plastics at elevated temperatures with regard to fire resistance of reinforced concrete members. Fibre reinforced polymer reinforcement for reinforced concrete structures. Detroit, Michigan, pp 43–54Google Scholar
  7. Del Prete I, Bilotta A, Nigro E (2015) Performances at high temperature of RC bridge decks strengthened with EBR-FRP. Compos B Eng 68:27–37CrossRefGoogle Scholar
  8. Eurocode2 (2004) Design of concrete structures, part 1–2: general rules-structural fire design. ENV 1992-1-2/UK: CEN: European Committee for StandardizationGoogle Scholar
  9. Fehérvári S (2008) Characteristics of tunnel fires. Concr Struct 9:56–60Google Scholar
  10. Hawileh R, Naser M (2012) Thermal-stress analysis of RC beams reinforced with GFRP bars. Compos B Eng 43(5):2135–2142CrossRefGoogle Scholar
  11. Hawileh R, Naser M, Zaidan W, Rasheed H (2009) Modeling of insulated CFRP-strengthened reinforced concrete T-beam exposed to fire. Eng Struct 31(12):3072–3079CrossRefGoogle Scholar
  12. Hawileh R, Naser M, Rasheed H (2011) 3D finite element transient thermal-stress analysis of FRP strengthened concrete beam exposed to top fire loading. Mech Adv Mater Struct 18(3):172–180CrossRefGoogle Scholar
  13. ISO834 (1975) Fire resistance tests—elements of building construction, International Organization for StandardizationGoogle Scholar
  14. Koch R, Karst J (2013) GFRP rebar for I-635 bridge over state Ave. In: Proceedings of the 20th bridge design workshop: bridge innovations, Kansas State University, ManhattanGoogle Scholar
  15. Naser M, Hawileh R, Rasheed H (2014) Performance of RC T-beams externally strengthened with CFRP laminates under elevated temperatures. J Struct Fire Eng 5(1):1–24CrossRefGoogle Scholar
  16. Naser M, Hawileh R, Rasheed H (2015) Modeling fire response of RC beams strengthened with CFRP laminates. American Concrete Institute (ACI) Special Publication (SP-301), Modeling of FRP Strengthening techniques in concrete infrastructure, SP-301-6Google Scholar
  17. Nigro E, Cefarelli G, Bilotta A, Manfredi G, Cosenza E (2011a) Fire resistance of concrete slabs reinforced with FRP bars. Part I: experimental investigations on the mechanical behavior. Compos B Eng 42(6):1739–1750CrossRefGoogle Scholar
  18. Nigro E, Cefarelli G, Bilotta A, Manfredi G, Cosenza E (2011b) Fire resistance of concrete slabs reinforced with FRP bars. Part II: experimental results and numerical simulations on the thermal field. Compos B Eng 42(6):1751–1763CrossRefGoogle Scholar
  19. Tan KH, Zhou Y (2011) Performance of FRP-strengthened beams subjected to elevated temperatures. ASCE J Compos Constr 15(3):304–311CrossRefGoogle Scholar
  20. Williams B, Bisby L, Kodur V, Green M, Chowdhury E (2006) Fire insulation schemes for FRP strengthened concrete slabs. Compos A Appl Sci Manuf 37(8):1151–1160CrossRefGoogle Scholar
  21. Yu B, Kodur VKR (2013) Factors governing the fire response of concrete beams reinforced with FRP rebars. Compos Struct 100:257–269CrossRefGoogle Scholar

Copyright information

© The Author(s) 2017

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Department of Civil EngineeringAmerican University of SharjahSharjahUnited Arab Emirates
  2. 2.Department of Civil EngineeringKansas State UniversityManhattanUSA

Personalised recommendations