tc17 presentation 11
TRANSCRIPT
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I.N. MarkouD. Christodoulou & A. Droudakis
Microfine Cements forPermeation Grouting
Democritus University of ThraceDepartment of Civil Engineering
GREECE
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Need for Microfine Cements
• Suspension grouts, prepared conventionally withordinary Portland cement, can be successfully
injected into gravels and coarse sands.
• Chemical grouts can permeate fine sands and
coarse silts, but they are expensive and pose
environmental and health problems.• As an alternative to chemical grouting of fine and
medium grained sands, the use of grouts prepared
with microfine cements has been proposed.
• The first microfine cement available commercially
was MC-500, manufactured by Onoda CementCorporation in Japan.
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Microfine Cement Definitions
• ACI Committee 552, Geotechnical Cement Grouting,defines microfine cement as a material in whichddmaxmax
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Manufacturing Processes
•• Dry grinding processDry grinding process
Fine grinding of an ordinary cement
•• Wet milling processWet milling process
On-site production of microfine cement-based
slurries with a special process, which allowsthe elimination of the larger particles ofcement (Legendre et al., 1987, De Paoli etal., 1992, Ahrens, 1997, Naudts & Landry,2003).
▪ Available Products: Cemill, Microsol
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Commercially Available Products
Manufacturer Cement Composition Grain Size (µm)Onoda MC-500 Slag+Portland dmax = 15
MC-300 Portland dmax < 40
MC-100 Slag dmax = 8
Ciment d’ Origny Spinor A12, A16 Slag d98 = 12, 16
Micromix dmax = 10
Microdur RS, RF, RU, RX d95 = 24, 16, 9.5, 6
Finosol F, U, X d95 = 16, 9.5, 6
Nittetsu Superfine, Superfine - L dmax = 10
BASF Cons. Chem. Rheocem 650, 800, 900 Portland d95
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Composition of Suspensions
•• Water to Cement (W/C) RatioWater to Cement (W/C) Ratio (by weight):▪ Thick suspensions (W/C → 0,7:1 -
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Microfine Cement Suspension
Properties
Thick Thin
Property min max min max
Unconfined Compression
Strength, 28 days (MPa)14 38 1 21
Apparent Viscosity, n (cP) 6 >100 2 69
Bleed Capacity (%) 0 20 2.5 80
Initial Setting Time (hrs) 1 26 4 45
Final Setting Time (hrs) 20 26 42 88
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Injection
Devices
(1-D)
Column diameter:2.2 – 51 cm
Column length:0.3 – 18 m !!!
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Device for Spherical Injections
The injection funnel represents 1/33 of a sphere andenables penetration depths of approximately 75 cm.
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Permeation Comparison
It is generally believed that microfine cements can beinjected into fine sands like many chemical solutions.
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Permeation Test Results
Reference W/C (by weight) Soil
Penetration
Length (m)
Zebowitz et al., 1989 2:1 medium-fine sand 1.5
Sano et al., 1996 5:1, 7.5:1, 10:1 fine sand 1.92
Fujii et al., 1996 10:1 medium-fine sand 2.0Van der Stoel, 1999 4:1 silty sand 2.5
Bouchelaghem & Vulliet,
20014:1 medium sand 0.8
Bouchelaghem & Almosni,
20034:1 medium sand 0.82
Dano & Hicher, 2003 6:1 fine sand 0.9
Mittag & Savvidis, 2003 5:1 fine sand 1.0Santagata & Santagata,
20032.75:1 medium-fine sand 0.46
Dano et al., 2004 6:1 two fine sands 0.9
Saada et al., 2005 5:1 fine sand 1.1
Andreou et al., 2006 5:1, 6.7:1, 10:1 fine sand 1.1
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Soil Improvement
• Reduction of Permeability Coefficient:1 – 5 orders of magnitude
Thick Thin
Property min max min max
Unconfined CompressionUnconfined Compression
Strength, 28 days (MPa)Strength, 28 days (MPa)4.4 16.2 0.5 13.2
Permeability Coefficient,Permeability Coefficient,
k (cm/s)k (cm/s)
5.5x10-8 9.2x10-8 10-7 10-2
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Shear Strength
*CG: Cementitious GroutReference: Krizek et al., 1986
Dano et al.,
2004
Fontainebleau
SandSeine River Sand
Parameters φ’ (deg) c’ (MPa) φ’ (deg) c’ (MPa)
Natural Sand 39 0.0 40 0.0
Sand+CG1* 42 0.2 42 0.18
Sand+CG2 43 0.3 43 0.25Sand+CG3 44 0.5 44 0.35
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Applications
Reference Cement Project Ground *Objective
Shimoda & Ohmori, 1982 MC–500 Railway tunnel Gravel 1, 2
Brand et al., 1988 MC–500 Tunnel Sand 1, 2
Weaver et al., 1992 MC–500 Waste burial Dolomite 1
Clarke, 1984 MC–500 Tunnel Granite 1
Dasika, 1985 MC–500 Building Sand 2
Winter et al., 1986 MC–500 Building Fine sand 2
Legendre et al., 1987 Microsol Oilwell Fine sand 1
Ballivy et al., 1997 Spinor A12 Masonry Gneiss 2
Palardy et. al, 2003 Spinor A12 Ventilation Tower Rock mass 1
*1: permeability reduction
*2: improvement of soil bearing capacity
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Research Project
• Title: Development and documentation of new groutingmaterials from Greek ultrafine cements for in-situ soil
improvement – reinforcement in construction
• Financing: European Union & Greek Ministry of Development• Participants:
1.Democritus University of Thrace, Dept. of Civil Engineering
(I. Markou, Assistant Professor, D. Christodoulou & A.Droudakis, Research Assistants)
2.University of Patras, Department of Civil Engineering
(D. Atmatzidis, Professor, & I. Pantazopoulos, Research
Assistant)
3.TITAN Cement Company
(D. Papageorgiou & Ch. Teas, Dr. Chemical Engineers)
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Cements • Cement types:
CEM I (Portland),CEM II/B-M
(composite) and
CEM IV/B
(pozzolanic)
according to EN
197-1 Standard
• Maximum grain
sizes: Ordinary,
38 µm, 18 µm
and 10 µm• Manufacturing
process: Dry
grinding process
0
20
40
60
80
100
0,11,010,0100,0
Grain size (µm)
F i n e r b y
w e i g h t ( % )
Κοινό
38 µm18 µm
10 µm
CEM I
Ordinary
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Grout Viscosity & BleedingCEM II + 1.4% SP, 18 µm
0
20
40
60
0 60 120 180 240 300
Time (min)
B l e e d i n g r a t e ( % ) κ
2:1
3:1
w/c : 1:1
CEM I, 18µmw/c: 1:1
10
100
1000
0 50 100 150 200
Time (min)
A p p a r e n t v i s c
o s i t y , n ( c P )
SP dosage
0.6%
0%
1.0%
1.4%
1.8%
Grouts with w/c=1:1 are stable (bleed capacity
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Grout Setting & Strength
• Initial setting times:4 – 8 hours
• Final setting times:
7 – 22 hours
• Pocket penetrometer
tests: grout strengthis equal to 450 kPa
after 4 – 29 hours
• Unconfined compr.strength: 1 – 11 MPa
after 28 days of
curing
CEM II + 1.4% SP, 8µm
0
2
4
6
8
10
0 5 10 15 20 25 30Curing time (days)
U n c o n f i n e d c o m p r e s
s i o n s t r e n g t h ( M P a ) Κ
1:1
2:1
3:1
w/c :
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Sands
0
20
40
60
80
100
0,010,101,0010,00
Grain size (mm)
F i n e r b y w e i g h t ( % )
5-10
10-14
14-25
25-50
50-100
100-200
• Six clean uniform sands (one coarse, three mediumand two fine sands)
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Laboratory Injections
Aims:• Injectability documentation
• Effectiveness determination
• Grouted soil design parameters(static & dynamic loading)
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Conclusions
Microfine cements are manufactured with drygrinding and microfine cement grouts can alsobe produced in-situ with wet milling process.
Microfine cement grouts with high water / cementratios can be successfully injected in fine sands.
Grouting with microfine cements improvessubstantially sand permeability and strength.
Microfine cements have been successfully usedin various grouting projects.
Research efforts on microfine cement groutingtechnology are in progress.