Bursting and Spalling in Pretensioned U-Beams - Ferguson ...

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Davis, R.T.; Buckner, C.D. & Ozyildirim, C. (2005), “Serviceability-Based DesignMethod for Vertical Beam End Reinforcement,” Proceedings of PCI NationalBridge Conference, Palm Springs, CA, 16-19 Oct 2005.Endicott, W.A. (2005), “A Fast Learning Curve,” Ascent, Vol. 10, No. 3, pp. 36-49.Folliard, K.J. et al. (2006), Preventing ASR/DEF in New Concrete: Final Report, Centerfor Transportation Research Report 0-4085-5, The University of Texas at Austin,234 pp.Folliard, K.J. (2008), Lecture Notes from Advanced Concrete Materials, CE 393,The University of Texas at Austin, Fall 2008.Fountain, R.S. (1963), A Field Inspection of Prestressed Concrete Bridges, PortlandCement Association, Skokie, IL, 50 pp.Gamble, W.L. (1997) “Comments on ‘Release Methodology of Strands to Reduce EndCracking in Pretensioned Concrete Girders’ by Kannel, French & Stolarski,”PCI Journal, Vol. 42, No. 4, pp. 102-103.Gergely, P.; Sozen, M.A. & Siess, C.P. (1963), The Effect of Reinforcement onAnchorage Zone Cracks in Prestressed Concrete Members, University of IllinoisStructural Research Series No. 271, 170 pp.Gergely, P. & Sozen, M.A. (1967), “Design of Anchorage Zone Reinforcement inPrestressed Concrete Beams,” PCI Journal, Vol. 12, No. 4, pp. 63-75.Gross, S.P. & Burns, N.H. (2000), Field Performance of Prestressed High PerformanceConcrete Highway Bridges in Texas, FHWA Report FHWA/TX-05/9-508/589-2,655 pp.Guyon, Y. (1955), Prestressed Concrete 2 nded. (English translation), F.J. Parsons,London, 543 pp.236
Hawkins, N. (1966), “The Behaviour and Design of End Blocks for PrestressedConcrete,” Civil Engineering Transactions, Vol. 8, No. 1, pp. 193-202.Holt, J. (2008), TxDOT, Personal Communications.Huang, D. & Shahawy, M. (2005), “Analysis of Tensile Stresses in Transfer Zone ofPrestressed Concrete U-Beams,” Transportation Research Record, No. 1928,pp. 134-141.Itani, R.Y. & Galbraith, R.L. (1986), Design of Prestressed Concrete Girders WithoutEnd Blocks, WSDOT Report WA-RD 81, 119 p.Iyengar, K.T.S.R. (1962), “Two-Dimensional Theories of Anchorage Zone Stresses inPost-Tensioned Prestressed Beams,” ACI Journal, Vol. 59, No. 10,pp. 1443-1466.Kannel, J.; French, C. & Stolarski, H. (1997), “Release Methodology of Strands toReduce End Cracking in Pretensioned Concrete Girders,” PCI Journal, Vol. 42,No. 1, pp. 42-54.Kapur, J. & Wilson, D. (2008), “Concrete Bridges in Washington State,” Aspire, Vol. 1,No. 3, pp. 46-48.Khaleghi, B. (2006), Splitting Resistance of Pretensioned Anchorage Zones, WSDOTDesign Memorandum, 23 Dec 2006.Krishnamurthy, D. (1970), “The Effect of the Method of Prestress Transfer on the End-Zone Stresses and Transmission Length of Pre-Tensioned Beams,” IndianConcrete Journal, Vol. 44, No. 3, pp. 110-117.Lenschow, R.J. & Sozen, M.A. (1965), “Practical Analysis of the Anchorage ZoneProblem in Prestressed Beams,” ACI Journal, Vol. 62, No. 79, pp. 1421-1439.Leonhardt, F. (1964), Prestressed Concrete Design and Construction 2 nd ed. (Englishtranslation), Wilhelm Ernst und Sohn, Berlin, 677 pp.237
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CopyrightbyDavid Andrew Dunkman2009
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Bursting and Spalling in Pretension
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Bursting and Spalling in Pretension
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2.4.2.3 Itani & Galbraith, 1986 ...
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4.2.2.4 Beam 1: Lateral-Bar Burstin
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List of TablesTable 2.1 Range of st
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Figure 2.25 Mechanical gage points
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Figure 3.30 Thermocouple placement
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CHAPTER 1Introduction1.1 IMPETUS FO
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At present, current end-region deta
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Figure 2.1 Severe cracking in a pre
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through use of tensioned, high-stre
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As splitting stress is bond-related
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Figure 2.6 Effect of bursting & spa
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magnitude of the end-region transve
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FEA can readily output color maps o
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2.3.1.3 Plastic Analysis of Beam En
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force can increase by 400% (Yettram
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2.4 EXPERIMENTAL STUDIES OF BURSTIN
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The trial specimens included one 40
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mechanical gage (2 in. gage length)
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Bursting stress(normalized by prest
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proprietary post-tensioning anchors
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Though Marshall and Mattock placed
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ectangular beam” (p. 21). At high
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Most beams observed to crack did so
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The behavior of these beams was dom
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2.4.2 Studies of End-Region Transve
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Figure 2.28 I-beams studied by Mars
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transverse forces compared to those
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(a) Actual spalling stress variatio
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stirrups in Gergely, Sozen and Sies
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50% more reinforcement than require
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strength concrete, increasingly hig
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the reinforcement located within th
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Typical crack patterns for the beam
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“Very common”crack locationPred
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Figure 2.38 Typical gage locations
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2.4.2.7 Smith et al., 2008Most rece
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the provided transverse reinforceme
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Itani and Galbraith (1986) reported
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Figure 2.45 Confining reinforcement
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cracks located along lines of prest
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odies relevant to pretensioned conc
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than that in another shape. For thi
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Figure 2.47 Required splitting rein
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No attempt was made in the Tentativ
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No citation is provided in the PCI
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Section Propertiesy b22.4 in.A 1120
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minimum for greater skews. For beam
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treatment (counting the transverse
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Pretensioned/post-tensioned beams h
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Figure 2.57 Harped strands in webs
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transversereinforcementwithin voidp
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2.8 SUMMARYIn this chapter, literat
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3.2.1.1 Linear and Nonlinear Stress
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Empirical expressions can be used t
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where: 0.021 = spalling force,
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3.3 CONCRETE PROPERTIES3.3.1 Concre
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It was reasoned that the dimensiona
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Splitting tensile-strength testing
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For temperature-match curing, therm
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3.4.1 Reinforcing-Bar Mechanical Te
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Grade 60 rebar yielded at 65 ksi an
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Equation 3.10where:ε1,2 = gage str
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Figure 3.17 Typical strand failure
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SouthNorth North120NorthSouthFigure
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Beam 1 also included an additional
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Figure 3.22 Strand strain-gage inst
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Figure 3.25 Interface board used to
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eam has a “hot spot” (measureme
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3.6 BEAM FABRICATION3.6.1 Beam Cast
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Figure 3.33 Installing the interior
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In order to use a pretensioning bed
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standardside-formprofilespecialtape
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Figure 3.41 Strands installed, tens
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Correspondence between the values o
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Figures 3.45 to 3.50 show the fabri
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Figure 3.49 Casting end block (and
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Figure 3.52 Detensioning by gradual
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CHAPTER 4Results & Discussion4.1 OV
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The strain time history for each ga
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1DNorthSouth1E18 ksi1C1C,E1D1521B1B
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Figure 4.4 Beam 1 prestress losses
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crack adjacent to this location was
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The temperatures in the end blocks
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Table 4.4 Beam 2 applied prestressi
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Figure 4.10 Beam 2 prestress losses
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terms of force distribution seems t
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limits were only exceeded at locati
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spalling stresses were measured in
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transverse reinforcement contained
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Based on Figure 4.18, the 4% Pi des
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Uniform and linearly-decreasing tra
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4.3.5 Contributing Factors to High
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stress ratio multiplied by a typica
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Figure 4.25 Relation between total
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4.4.1 Recommended Texas U-Beam Rein
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Figure 4.28 Proposed end-region det
Page 202 and 203: At present, AASHTO LRFD (2009) lack
Page 204 and 205: CHAPTER 5Conclusions5.1 SUMMARY OF
Page 206 and 207: tested at transfer and under shear
Page 208 and 209: APPENDIX ADatabase of Transverse-Ba
Page 210 and 211: 194Figure A.1 U-beam with skewed en
Page 212 and 213: 196Figure A.3 Shallow Texas bulb te
Page 214 and 215: 198Figure A.5 Lightweight-concrete
Page 216 and 217: 200Figure A.7 Washington bulb tee (
Page 218 and 219: 202Figure A.9 Nebraska bulb tees an
Page 220 and 221: 204Figure A.11 Nebraska bulb tees a
Page 222 and 223: 206Figure A.13 Shallow I-beams
Page 224 and 225: where:= lower-bound concrete tensil
Page 226 and 227: B.3.4 Transmission Length (Clause 6
Page 228 and 229: Equation B.11where:= bursting force
Page 230 and 231: 50High Web gage4030Max Moment heigh
Page 232 and 233: C.2 CONCRETE RELEASE STRENGTHA bott
Page 234 and 235: Table C.1 Specimen Design for Beams
Page 236 and 237: Table D.1 Beam 1 match-cured cylind
Page 238 and 239: D.1.2 Beam 28Release-Point Cylinder
Page 240 and 241: Cylinder Strength (ksi)131197Ambien
Page 242 and 243: D.2 REINFORCING-BAR MODULUS & STREN
Page 244 and 245: APPENDIX EEnd-Block Temperature Pro
Page 246 and 247: E.2 BEAM 2T max = 142°F∆T = 30°
Page 248 and 249: REFERENCESREFERENCED STANDARDSAmeri
Page 250 and 251: Fédération Internationale du Bét
Page 254 and 255: Lin, T.Y. & Burns, N.H. (1981), Des
Page 256 and 257: Stone, W.C. & Breen, J.E. (1984),
Page 258: VITADavid Andrew Dunkman was born 2
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