Lightweight Concrete for High Strength - Expanded Shale & Clay

More documents

Recommendations

Info

objective of this test was to examine the shear strength of concrete. The shear crack running from bottom to top occurred very suddenly and violently and was indicative of a pure shear failure. Girders undergoing shear failures precipitated by strand slip showed different failure modes. Figure 5.14 Girder Test G2A-Center Showing Pure Shear Failure 5.8 Cracking Results Table 5.7 provides an overview of the predicted and experimental cracking moment for each girder test. The experimental cracking moment was determined by examining the experimental load vs. deflection plot identifying the point at which a slope change occurred. In every case, the cracking load indicated on the load vs. deflection plot matched the load recorded where visible flexural cracking first occurred. Based on the use of equation 5.1, the predicted cracking moment for the G2 series girders was 10.8 percent greater than for G1 girders. f cr − Pr ed = 7.5λ f ' c (5.1) where λ is the correction factor of unit weight of concrete, taken as 0.85. 5-18
Since G2 girders had a higher concrete compressive strength than G1 girders, this was logical. Experimentally, the G1 and G2 series average cracking moments were about identical. It is important to note that the predicted cracking moments appeared to become less conservative as compressive strength increased. Test # Table 5.7 Cracking Moment Results Predicted M cr (ft-kips) Experimental M cr (ft-kips) Percent Difference G1A-East 1052 1224 16.4% G1A-West 1005 1109 10.4% G1A-Center 1065 1064 -0.2% G1B-East 1019 1133 11.2% G1B-West 1004 1109 10.4% G1B-Center 1029 1188 15.5% G1C-East 999 1155 15.6% G1C-West 971 1145 17.9% G1C-Center 1035 1142 10.4% G2A-East 1165 1220 4.7% G2A-West 1136 1176 3.5% G2A-Center 1189 1124 -5.5% G2B-East 1177 1110 -5.6% G2B-West 1133 1124 -0.9% G2B-Center 1200 1210 0.8% G2C-East 1059 1079 1.9% G2C-West 1025 1094 6.8% G2C-Center 1082 1219 12.6% G1 Average 1020 1141 12.0% G2 Average 1130 1151 2.0% G1 Std Dev 5.4% G2 Std Dev 5.8% 5.9 Shear Behavior The flexure shear strength was calculated using AASHTO equation (5.2): V ci ' fc ' = 0.6λ b d + V 1000 d ViM + M where V d is the shear force from dead load of girder plus deck slab. cr max ' fc ' ≥ 1.7λ b d 1000 (5.2) 5-19
Page 1 and 2:
School of Civil and Environmental E
Page 3 and 4:
ACKNOWLEDGMENTS The research presen
Page 5 and 6: A statistical evaluation based on f
Page 7 and 8: 5.6 - Transfer Length 5-13 5.7 - Gi
Page 9 and 10: Report ACI 318- 99 AASHTO Standard
Page 11 and 12: Chapter 1. Introduction 1.1 Purpose
Page 13 and 14: Long term properties including pret
Page 15 and 16: ottom flange. Prestressing strands
Page 17 and 18: 12500 12000 Concrete Strength, fc'
Page 19 and 20: Chapter 3. Mix Designs, Field Evalu
Page 21 and 22: Variation of coarse-to-fine aggrega
Page 23 and 24: 3.2.1 Compressive Strength Figure 3
Page 25 and 26: Table 3.5 Chloride Permeability --
Page 27 and 28: 12,000 11,500 11,000 Compressive St
Page 29 and 30: 1,400 1,300 1,200 1,100 Experimenta
Page 31 and 32: strength (10L made in the laborator
Page 33 and 34: The 50% and 90% of the 620-day cree
Page 35 and 36: 700 600 10,000-psi Measured Shams &
Page 37 and 38: a Creep Coefficient 3.0 2.5 2.0 1.5
Page 39 and 40: Chapter 5. Behavior of AASHTO Type
Page 41 and 42: Portion of Girder Damaged During Te
Page 43 and 44: 2” End Cover (Typ both ends) 4 Sp
Page 45 and 46: 5.3 Instrumentation The surface of
Page 47 and 48: Figure 5.7 Installation of stirrups
Page 49 and 50: Table 5.3 Girder concrete propertie
Page 51 and 52: 120 100 80 Stress (ksi) 60 40 20 0
Page 53 and 54: Table 5.5 -Transfer Length Results
Page 55: Figure 5.12 Typical flexural failur
Page 59 and 60: V " pc cw− Pr ed = ft −Pr ed 1
Page 61 and 62: Test # Table 5.9 Predicted vs. Expe
Page 63 and 64: this research project, modification
Page 65 and 66: Chapter 6. Prestress Losses in HPLC
Page 67 and 68: losses in the 10,000-psi girders to
Page 69 and 70: Microstrains (in/inx10 -6 ) 0 500 1
Page 71 and 72: 6.3 Conclusions Regarding Prestress
Page 73 and 74: 7.3 Transfer Length An evaluation o
Page 75 and 76: Shrinkage after 620 days of drying
Page 77 and 78: More research is required to examin
Page 79 and 80: Appendix A. Background A.1 Introduc
Page 81 and 82: Raithby and Lydon described the use
Page 83 and 84: are normally recognized as being on
Page 85 and 86: aggregate must be saturated by pres
Page 87 and 88: A.7.2 Strength Ceiling Harmon discu
Page 89 and 90: compared to lower strength specimen
Page 91 and 92: A.8.8 Deatherage, Burdette and Chew
Page 93 and 94: 3. Concrete compressive strength at
Page 95 and 96: findings were comments that the AAS
Page 97 and 98: including strand diameter, embedmen
Page 99 and 100: l d = l t + l fb = f si 3 d b + 1.5
Page 101 and 102: l d = l t + l fb ⎛ = ⎜ ⎝ f d
Page 103 and 104: Table A.1 Summary of Development Le
Page 105 and 106: strand release, the strand attempts
Page 107 and 108:
Appendix B. Creep and Shrinkage B.1
Page 109 and 110:
Changes in moisture migration: the
Page 111 and 112:
t′: age of concrete at loading (d
Page 113 and 114:
s: slump (in) γ ψ ⎧ 0.30 −1.4
Page 115 and 116:
t: age of concrete (days) t 0 : age
Page 117 and 118:
where ε sh ∞ ⎧ 510 µε for st
Page 119 and 120:
left girder-end. The dimension L wa
Page 121 and 122:
6” 85” 50” Segment of girder
Page 123 and 124:
146” 89” 96” 137” Stirrups
Page 125 and 126:
were added in a specific sequence f
Page 127 and 128:
C.2.3 Formwork Removal, Detensionin
Page 129 and 130:
Figure C.19 Mostafa Prestressing St
Page 131 and 132:
Figure C.22 Ms. Lyn Clements (GDOT)
Page 133 and 134:
If significant strand end slip over
Page 135 and 136:
CSS at Level of Bottom Strands (µ
Page 137 and 138:
Appendix D. Prestress Losses in HPL
Page 139 and 140:
E ps : elastic modulus of prestress
Page 141 and 142:
D.2.2. AASHTO-LRFD Refined Estimate
Page 143 and 144:
∆f log(24 ⋅t) ⎛ f ⎜ ⎞ 55
Page 145 and 146:
P i : initial prestressing force af
Page 147 and 148:
References AASHTO (1996), Standard
Page 149 and 150:
ASTM C 618, Standard Specification
Page 151 and 152:
Guide for Structural Lightweight Ag
Page 153 and 154:
Martin, L. D., Scott, N. L., “Dev
Page 155:
Shahawy, M. A., Batchelor, B., “S
show all

Lightweight Concrete for High Strength - Expanded Shale & Clay

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?