compatibility of ultra high performance concrete as repair material

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property of the concrete has higher scatter than that of the compressive strength. Besidesthis, it has to be added that, in the pull off test, there are several factors that can affect theresults, including the drilling process and the difficulty of applying a perpendicular forceto the surface.4.3.2 DiscussionThe results of this test show that the bond tensile strength largely accomplishes with theminimum requirements for bond strength specified by ACI 546.3R-06. However, it wasnot possible to estimate the actual strength of the bond due to the fact that the concretesubstrate failed at low tensile stress.The COV’s, attained in this study, varies from 6.1 to 18.4%, for that reason, it can bestated that the results scattering is low. Bonaldo et al. (2005) carried out the pull-off usingthe same loading equipment as this research obtaining COV’s up to 38.9%. There aremany factors that might influence in the pull off results, including the coarse aggregate(shape, maximum diameter and strength) of the concrete substrate, coring depth intosubstrate, the overlay thickness, concrete substrate strength, core diameter, loadeccentricity and loading rate (Bonaldo et al. 2005). FEA seems to be necessary tounderstand the stress distribution along the core. A concentration of stress due to theelasticity mismatch might have taken place, resulting in a lower failure load.94
5 Conclusions and further researchEvery year transportation agencies need to increase their budgets for maintaining andrepairing infrastructure due to the large number of structures that are reaching theirservice lives. In response, the transportation industry needs to adapt this environment bydeveloping new techniques to evaluate and repair this damage. The increasing need ofrehabilitation is driving the development of new materials, such as, low slump denseconcrete or polymer-impregnated concrete, which have potential advantages for theconstruction of new structures or their rehabilitation. The purpose of this research is notto demonstrate that UHPC has better qualities than other construction materials, but toshow that this new advanced cementitious material exhibits outstanding properties thatcan result in great progress for the construction industry in some circumstances, such asharsh environments, in which most of the current construction materials fall short. Theauthor recognizes that UHPC will not replace the general use of the traditional materials,e.g. portland cement or latex-modified concrete, because for some applications thesemeet all the requirements, but the proposed solution may offer a competitive alternativeor even a superior one in some applications of the construction industry.The results of this investigation provides information about the bond performancebetween UHPC and concrete. The evaluation is with respect to time of the bond strengthunder ambient environmental conditions with consideration of the influence of thewetting conditions of the concrete substrate, the performance of the composite systems inharsh enviroments and the effect of the different surface treatments of the concretesubstrate are assessed.5.1 ConclusionsIt should be emphasized that the following conclusions are given for the specific UHPCused in this study (Ductal®JS1000) and no bonding agent was used. The conclusions aregrouped into: splitting tensile test, slant-shear test, pull-off test and overall performance.95
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COMPATIBILITY OF ULTRA HIGH PERFORM
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Table of ContentsList of Figures ..
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4.3.2 Discussion ..................
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Figure 3.14 CSP index .............
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Table 4.7 Summary of indirect tensi
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List of AbbreviationsACI.AFtASTM.CO
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1 Introduction and MotivationCurren
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2 Background and Literature ReviewT
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spaces and to decrease the amount o
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water/binder=constantChoose steel f
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UHPC formulations and provides a se
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Table 2.3Comparison of UHPC materia
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esults obtained in this project wer
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2.1.3.4 Environmental Impact of UHP
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1997). Emmons and Vaysburd (1996) d
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e) ConstructabilityIt is recommenda
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Table 2.5, continuedCementitious ma
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• Rehabilitation of a bridge pier
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UHPC is a cost-effective solution i
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apparatus will measure the shear st
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substrate while the scarifying meth
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such test configuration, this upper
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From the equilibrium of forces of F
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The first layer, also called penetr
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3 MethodologyThis report aims to st
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f sp = 2 ∗ PA ∗ π in psi Equat
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that the bond interface, in this lo
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 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.
Page 126 and 127: Table 7.33rd mix for the splitting
Page 128 and 129: Table 7.51st mix for the splitting
Page 130 and 131: 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
Page 138 and 139: 10 Appendix: Splitting tensile pris
Page 140 and 141: Table 10.1, continued.128
Page 148 and 149: Table 10.2Splitting monolithic NSC
Page 150 and 151: 11 Appendix: Slant-shear specimens
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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
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End Page 1235Type of UsePortionNumb
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Type of UseIntended publisher of ot
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