compatibility of ultra high performance concrete as repair material

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that the bond interface, in this loading configuration, undergoes direct tension which isthe most severe stress state (Robins and Austin 1995).Sprinkel (1997) described that the tensile failures that take place at a depth lower than ¼inch into the substrate material often is a sign of that the substrate surface hadmicrocracks after the surface treatment. In the same way, tensile failures that occur at adepth equal or greater than ¼ inch indicate that the substrate surface was preparedcorrectly.Cleland and Long (1997) carried out an extensive experimental program to assess thevariability of this method. Five overlay materials, four surface treatments and twoconditions for the substrate (cast surface and fractured surface) were used. The authorconcluded that the coefficient of variation (COV) is typically about 20%.Whereas Robinsand Austin (1995) obtained coefficients of variation from 8% to 40% with an average of19% in his study of the bond strength under direct tension between concrete substratewith sand/cement and polymer-modified mortars.ASTM C 1583 (Standard Test Method for Tensile Strength of Concrete Surfaces and theBond Strength or Tensile Strength of Concrete Repair and Overlay Materials by DirectTension) establishes that the steel disk has to have a 2 in diameter and at least a 1 inthickness and the core has to penetrate at least 0.5 in depth below the interface. Thetensile strength is estimated according to Equation 3.2.f t = T A in psi Equation 3.2where f t is the direct tensile strength, T is the tensile load and A is the area of testspecimen. Figure 3.4 shows a diagram of the test.Issa et al. (2008) showed by means of FEA that the bond tensile strength increasesrapidly for overlay thickness of less than 1.5 in and a mild increase after this value foroverlay material compressive strengths from 4000 psi to 7000 psi.42
3.2 MaterialsComposite specimens were composed of UHPC and conventional concrete for all tests.This section describes the main characteristics of the UHPC and NSC mixes done to castall composite samples.3.2.1 UHPC mixingDuctal®JS1000 brand UHPC manufactured by Lafarge North America was used asoverlay material. Graybeal (2006) presented an extensive mechanical and durabilitycharacterization of this material. A Doyon BFT-060 planetary mixer was used to make allUHPC mixes. The proportions of the UHPC constituents shown in Table 3.1 were used tocast all UHPC batches of 0.65 ft 3 (18 l). Figure 3.1 shows details of the mixer, paddle,steel fibers and the flow test equipment.Table 3.1Ductal® (JS1000-Grey Premix) mix proportions for 0.65 ft 3Constituents Amount (lbs) Amount (kgs)Ductal®Grey Premix 87.06 39.48Steel Fibers (8x10 -3 -in dia. by 0.5-in long) 6.19 2.81Superplastizer (Chryso Premia 150) 1.19 0.54Water 5.11 2.32(a) Doyon BFT-060planetary mixer.(b) Mixer paddle. (c) Steel fibers. (d) Equipment for the Slumptest.Figure 3.1 Equipment and material to cast UHPC43
Page 1 and 2:
COMPATIBILITY OF ULTRA HIGH PERFORM
Page 3 and 4: Table of ContentsList of Figures ..
Page 5 and 6: 4.3.2 Discussion ..................
Page 7 and 8: Figure 3.14 CSP index .............
Page 9 and 10: Table 4.7 Summary of indirect tensi
Page 11 and 12: List of AbbreviationsACI.AFtASTM.CO
Page 13 and 14: 1 Introduction and MotivationCurren
Page 15: 2 Background and Literature ReviewT
Page 18 and 19: spaces and to decrease the amount o
Page 20 and 21: water/binder=constantChoose steel f
Page 22 and 23: UHPC formulations and provides a se
Page 24 and 25: Table 2.3Comparison of UHPC materia
Page 26 and 27: esults obtained in this project wer
Page 28 and 29: 2.1.3.4 Environmental Impact of UHP
Page 30 and 31: 1997). Emmons and Vaysburd (1996) d
Page 32 and 33: e) ConstructabilityIt is recommenda
Page 34 and 35: Table 2.5, continuedCementitious ma
Page 36 and 37: • Rehabilitation of a bridge pier
Page 38 and 39: UHPC is a cost-effective solution i
Page 40 and 41: apparatus will measure the shear st
Page 42 and 43: substrate while the scarifying meth
Page 44 and 45: such test configuration, this upper
Page 46 and 47: From the equilibrium of forces of F
Page 48 and 49: The first layer, also called penetr
Page 50 and 51: 3 MethodologyThis report aims to st
Page 52 and 53: f sp = 2 ∗ PA ∗ π in psi Equat
Page 56 and 57: Ductal® premix is typically compri
Page 58 and 59: associated test results (temperatur
Page 60 and 61: Figure 3.2 Detail of splitting tens
Page 62 and 63: 3.3.3 Pull-off testPull off test wa
Page 64 and 65: (a) Chipped surface, slightlybrushe
Page 66 and 67: (a) Molds to cast slant shearspecim
Page 68 and 69: Timber moulds were used to cast the
Page 70 and 71: macrotexture depth was measured in
Page 72 and 73: As shown in the above tables, the m
Page 74 and 75: (a) Concrete substrate under water
Page 76 and 77: used, as shown in Figure 3.17. A fa
Page 78 and 79: Equation 2.2 and Equation 2.3 were
Page 80 and 81: (a) Steel disks glued to the UHPC s
Page 82 and 83: value to the lowest one in the foll
Page 84 and 85: Transversal frequency (Hz)255025002
Page 86 and 87: 115113Relative Dynamic Modulus (%)1
Page 88 and 89: Only those specimens with a grooved
Page 90 and 91: Table 4.6, continued.MeanMeanCOV,st
Page 92 and 93: concrete or bond/concrete while for
Page 94 and 95: surface treatment applied. In contr
Page 96 and 97: Table 4.8Summary of slant-shear tes
Page 98 and 99: (a) B(C): Bond due to concrete fail
Page 100 and 101: 3143Bond Capacity, (psi)30002500200
Page 102 and 103: The different failure modes obtaine
Page 104 and 105:
failures occurred in the concrete s
Page 106 and 107:
property of the concrete has higher
Page 108 and 109:
5.1.1 Combination of Splitting Tens
Page 110 and 111:
5.1.4 Overall performancea. For thi
Page 112 and 113:
mismatch and load eccentricity. Tho
Page 114 and 115:
6 ReferenceAbu-Tair, A. I., Rigden,
Page 116 and 117:
Climaco, J. C. T. S., and Regan, P.
Page 118 and 119:
Graybeal, B., and Tanesi, J. (2007)
Page 120 and 121:
Misson, D. (2008). "Influence of Cu
Page 122 and 123:
Silfwerbrand, J. (1990). "Improving
Page 124 and 125:
7 Appendix: NSC mix designsTable 7.
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Table 7.33rd mix for the splitting
Page 128 and 129:
Table 7.51st mix for the splitting
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Table 7.73rd mix for the splitting
Page 132 and 133:
Figure 8.2 Concrete retarder inform
Page 134 and 135:
Table 9.1, continued.BrBr w/oBr 300
Page 136 and 137:
Table 9.2, continued.TrialBrushed 6
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10 Appendix: Splitting tensile pris
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Table 10.1, continued.128
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Table 10.2Splitting monolithic NSC
Page 150 and 151:
11 Appendix: Slant-shear specimens
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Page 154 and 155:
Page 156 and 157:
PortionNumberof 1figures/tables/ill
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Figure 2.5Miguel Angel Carbonell Mu
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Miguel Angel Carbonell Munoz Mon, M
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Miguel - not sure what you need fro
Page 164 and 165:
End Page 1235Type of UsePortionNumb
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Type of UseIntended publisher of ot
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