compatibility of ultra high performance concrete as repair material

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apparatus will measure the shear strength of either the overlay and old materials. Due tothis, the pull off test is more suitable test to carry out in situ rather than the guillotine.The third category of bond strength tests includes all those tests in which the bond isunder a combined state of shear and compression stresses. The shear-compression test (d)and the slant shear test (k) belong to this category (Espeche and Leon 2011).Figure 2.7 Most common bond strength tests. Espeche and Leon (2011)2.3.2 Surface PreparationOne of the most critical steps in the rehabilitation of concrete structures is the removingof the unsound concrete and preparation of the substrate surface. An adequate surfacetreatment does not damage the substrate and provides sufficient roughness assure a good28
ond between the substrate and the overlay materials. International Concrete RepairInstitute (1997) categorizes the different mechanisms to remove damaged concrete intothe following groups:• Erosion (grinding, high-pressure water jetting)Hydro-demolition, also called hydro-jetting or hydro-blasting, followed by powerwashing creates an outstanding bonding surface with no microcracks in the treatmentsurface. Because of this, this method has arisen as the most effective way to removedamage concrete and also provides an irregular wavy surface profile. The water pressureapplied is often in the range from 12,000 to 35,000 psi. This technique presents theadvantage that does damage in the reinforcing steel when removing concrete fromunderneath, and also removes rust accumulation. Another advantage is the increase ofmicropores in the cement paste (Hindo 1990; Silfwerbrand 1990; Sprinkel 1997).Grinding methods are used to remove deposit and to smooth a surface profile. Thismethod consists in applying a grinding stone or disc under pressure to the surface until aflat surface is obtained (International Concrete Repair Institute 1997).• Impact (scarifying, scabbling, milling/rotomilling, needle scaling)Milling treatments consist of numerous teeth mounted on a rotating drum impacting onthe concrete surface. This technique presents the advantage of being the most economicalmethod to remove the concrete. Its main shortcoming is that it fractures the concretesurface that remains, causing a low fracture tensile strength. The overlay materialfrequently delaminates if the repair material is placed on the milled surface withoutapplying a shotblasted, or another surface treatment to remove all of the microfracturedsurface on the concrete (Sprinkel 1997).Scarifying and needle scaling are similar methods to milling treatment and are based onimpacting the concrete surface by means of rotatory action of thoothed washers(scarifying) and pointed tips of a pile of steel rods pulsed by compressed air (needlescaling). Both of them have a moderate risk of creating a bruised layer in the remaining29
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 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 54 and 55: 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 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.
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 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
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
PortionNumberof 1figures/tables/ill
Page 158 and 159:
Figure 2.5Miguel Angel Carbonell Mu
Page 160 and 161:
Miguel Angel Carbonell Munoz Mon, M
Page 162 and 163:
Miguel - not sure what you need fro
Page 164 and 165:
End Page 1235Type of UsePortionNumb
Page 166 and 167:
Type of UseIntended publisher of ot
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