Lightweight Concrete for High Strength - Expanded Shale & Clay

More documents

Recommendations

Info

Shrinkage of concrete. Prestress losses due to drying shrinkage are estimated by Equation D.16. The denominator K SE represents the stiffening effect of the steel and the effect of concrete creep. Without K SE the losses due to drying shrinkage are somewhat overestimated. E ps SH = ( ε sh ) ⋅ (D.16) t K SE where SH: shrinkage of concrete loss (ksi) (ε sh ) t : shrinkage strain as defined by ACI-209 (Equation B.3 of Appendix B) E ps : Elastic modulus of prestressing steel K SE = 1 + n ⋅ ρξ =1.25 (design simplification) s n: modular ratio at the time of prestressing ρ: non-prestressing reinforcement ratio ξ s : cross section shape coefficient Steel relaxation. Steel relaxation losses depend on the steel of the strands (stress-relieved or low relaxation), and time. For low relaxation strands, the relaxation losses are given by Equation D.17. [] t RE = 0.005⋅ f pj ⋅ log10 (D.17) where RE: steel relaxation loss (ksi) f pj : initial prestress (ksi) t: time under load in hours (for t>10 5 , RE = 0 . 025⋅ f pj ) D-10
References AASHTO (1996), Standard Specifications for Highway Bridges, 16 th ed., American Association of State Highway and Transportation Officials, Washington, D. C., 1996. AASHTO-LRFD (1998), LRFD Bridge Design Specifications, American Association of State Highway and Transportation Officials, Washington, D. C., 1998. ACI 318-89, Building Code Requirements for Reinforced Concrete, ACI 318-89, and Commentary, American Concrete Institute, Detroit, 1989. ACI 318-99, Building Code Requirements for Reinforced Concrete, ACI 318-99, and Commentary, American Concrete Institute, Detroit, 1999. ACI Manual of Concrete Practice, “Standard Practice for Selecting Proportions for Structural Lightweight Concrete (ACI 211.2-91), American Concrete Institute, Detroit, 1996. ACI-Committee116 (2000) "Cement and Concrete Terminology", ACI Manual of Concrete Practice, American Concrete Institute, Farmington Hills, MI, pp. 116R.1-16R.73. ACI-Committee209 (1971). "Effect of Concrete Constituent, Environment, and Stress on the Creep and Shrinkage of Concrete". Designing for Effects of Creep, Shrinkage, Temperature in Concrete Structures, Farmington Hills, MI, American Concrete Institute. ACI-Committee209 (1992/Reapproved 1997) "Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures", ACI Manual of Concrete Practice, American Concrete Institute, Farmington Hills, MI, pp. 209R.1-09R.47. ACI-Committee213 (1987/Reapproved 1999) "Guide for Structural Lightweight Aggregate Concrete", ACI Manual of Concrete Practice, American Concrete Institute, Farmington Hills, MI, pp. 213R.1-31R.27. ACI-Committee363 (1992/Reapproved 1997) "State-of-the-Art Report on High-Strength Concrete", ACI Manual of Concrete Practice, American Concrete Institute, Farmington Hills, MI, pp. 363R.1-63R.55. ASTM C 31, Standard Practice for Making and Curing Concrete Test Specimens in the Field, American Society for Testing and Materials, West Conshohocken, PA, 1998, 5 pp. ASTM C 33, Standard Specification for Concrete Aggregates, American Society for Testing and Materials, West Conshohocken, PA, 1999, 8 pp. ASTM C 39, Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, American Society for Testing and Materials, West Conshohocken, PA, 1999, 5 pp. References-1
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 and 56:
Figure 5.12 Typical flexural failur
Page 57 and 58:
Since G2 girders had a higher concr
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: P i : initial prestressing force af
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

Create successful ePaper yourself

Delete template?

Save as template?