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1 Introduction The codes that have been used and are referred to in this paper: Swedish Codes: BBK94 (1995) and BV BRO94 (1996). EC2-1 (1991): Eurocode 2: Design of Concrete Structures, Part 1: General rules and rules for buildings. EC2-2 (1995): Eurocode 2: Design of Concrete Structures, Part 2: Concrete Bridges. EC2-draft (1999): First Draft of Eurocode2: ”Design of concrete structures – Part 1: General rules and rules for buildings” (December 1999), [CEN/TC 250/sc 2 N314]. prEN 1992-1:2001 (1 st draft). Since a comparison of this kind is not “easy” due to the differences in strength classes, partial safety factors, load combinations etc., this comparison is made in such a way that the load calculation is made according the Swedish Codes. However, the strength classes are taken from the EC2-draft (1999). The bridge that has been used in this example is the Lautajokki Bridge (which was exposed to fatigue tests at LTU in 1996). The calculation is made on 1 m of the slab. The load case that has been used for the calculation is shown in Figure 1.1, Figure 1.2 and Figure 1.3. ~750 1700 1500 1700 - 2 - ~750 Figure 1.1 Load case with two bogies from two iron ore wagons, Nilsson et al. (1999). ~1540 3100 Figure 1.2 Cross-section of the Lautajokki Bridge, Nilsson et al. (1999). 600 320
φ16 s100 B=1000 - 3 - d=295 Figure 1.3 Reinforcement in the longitudinal direction in the slab in the Lautajokki Bridge. 2 Loads Load history To give an idea of how many load cycles the bridge already had been subjected to during its service life, the following estimation has been made: Variable load: According to Banverket (Swedish National Rail Administration) this particular railway line between Boden-Gällivare has been subjected to the following traffic: Year Gross loads [Mtons] 1968 11.39 1969 13.24 1970 14.508 1971 13.214 1972 12.647 1973 14.486 1974 19.225 1975 15.947 1976 13.379 Sum: 128.036 This corresponds to 128.036 / 9 = 14.2 Mtons/year. About 81 % of this load is iron ore trains with the axle load 22.5 tons while the rest is trains with lower axle loads. With a load cycle of four axles (two axles on one wagon + two axles on the next wagon, see Figure 1.1) we will have: 0.81 ⋅14.2 = 0.13 M cycles/year with the axle load 22.5 tons. 4 ⋅ 22.5 During the 21 years (1968-1988) the bridge was in traffic it has been exposed to approximately, 21 · 0.13 = 2.7 M cycles. Loads The loads are calculated according to the Swedish Codes. In the Swedish Code the self-weight of reinforced concrete is 24 kN/m 3 .
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LICENTIATE THESIS Evaluation of Con
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Preface This licentiate thesis pres
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Evaluation of Concrete Structures I
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Evaluation of Concrete Structures I
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Evaluation of Concrete Structures 4
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A. Simplified check A1. In-situ ins
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Evaluation of Concrete Structures G
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Lok-Strength & Capo-Strength F [kN]
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Evaluation of Concrete Structures a
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Evaluation of Concrete Structures t
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Evaluation of Concrete Structures d
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Evaluation of Concrete Structures T
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Evaluation of Concrete Structures -
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6 Outlook Evaluation of Concrete St
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Evaluation of Concrete Structures E
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Paper A CONCRETE STRENGTH DEVELOPME
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determine the in-place strength of
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strength could be the fact for all
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German Petersen & Poulsen (1993), s
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Rebound test (Schmidt-hammer) The r
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expected (about 8 MPa). But for the
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Figure 8 shows the location where t
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Tensile strength [MPa] 6.0 5.0 4.0
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Table 4 Mean value and standard dev
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Lok-Strength & Capo-Strength F [kN]
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fcc fct concrete compression streng
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The values that have been used are:
Page 73 and 74: LOAD CARRYING CAPACITY OF CRACKED C
Page 75 and 76: Figure 1 Principal drawing of teste
Page 77 and 78: Class 3. OK / Green: No visible cra
Page 79 and 80: 0.5 1.0 +15 kNm 0.5 0.5 1.0 0.5 -11
Page 81 and 82: Horizontal force [kN] 100 80 60 40
Page 83 and 84: TEST SET-UP AND RESULTS Bending cap
Page 85 and 86: The displacement was measured by fo
Page 87 and 88: Figure 18 Failure of sleeper no. 10
Page 89 and 90: Sleeper No. 17 looks more like the
Page 91 and 92: c2 75 á 100 where ψ ′ c = = = 0
Page 93 and 94: The obtained stress σ t = 4.45 MPa
Page 95 and 96: M f,rail moment bearing capacity at
Page 97: Paper C CONCRETE FATIGUE CAPACITY.
Page 100 and 101: FATIGUE OF CONCRETE A common way to
Page 102 and 103: notch is deep enough that is). When
Page 104 and 105: Figure 5 Test set-up uniaxial tensi
Page 106 and 107: Table 1 A summary of all uniaxial t
Page 108 and 109: Strain [‰] 0.8 0.6 0.4 0.2 0 Phas
Page 110 and 111: 11) the start of phase 3 takes plac
Page 112 and 113: ACKNOWLEDGEMENTS The study has been
Page 114 and 115: APPENDIX A Evaluated data from the
Page 116 and 117: C = dε / dN [× 10 −6 ] 100 10 1
Page 118 and 119: Test series A: S min = σ min / f c
Page 121: Paper D SHEAR FATIGUE CAPACITY - A
Page 126 and 127: Dead Loads: Slab: 0.320 m á 24 kN/
Page 128 and 129: the equations to calculate the desi
Page 130 and 131: where ηγm is 1.5 for concrete (co
Page 132 and 133: different besides the strength clas
Page 134 and 135: Table 4.2 Fatigue strength. Number
Page 136 and 137: The shear force capacity, V Rd1, fo
Page 138 and 139: σ cd,min,equ lower stresses of the
Page 140 and 141: 6.2 Strength values at fatigue load
Page 142 and 143: 6.3 Strength values at fatigue load
Page 144 and 145: 1 − 0.7166 14 ⋅ = 4.71 < 6 ⇒T
Page 146 and 147: The “new” equation for the desi
Page 149: Appendix A. Concrete Codes Excerpt
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DOCTORAL AND LICENTIATE THESES Divi
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