Role Of Admixture In Concrete
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ROLE OF ADMIXTURES IN READYMIX CONCRETE
Contents 1
INTRODUCTION
2 GLENIUM CONCRETE 3 SHRINKAGE REDUCING CONCRETE 4 ULTRA HIGH STRENGTH CONCRETE 5 CONCLUSION
Admixtures?
What admixtures can do!
What Admixtures can do!
Chemical Admixtures
ASTM C 494
EN 934 – 2
IS 9103:2003
Chemical Admixtures Type
Description
A
Water Reducing admixture (WRA)
B
Retarding Admixture
C
Accelerating Admixture
D
Water Reducing & Retarding Admixture
E
Water Reducing & Accelerating Admixture
F
High Range Water Reducing Admixture (HRWRA)
G
High Range Water Reducing & Retarding Admix
Slump flow [cm]
Main effect of plasticizing admixtures
1
with Plasticizer 2
without Plasticizer Water/Cement Ratio
1
Higher workability at constant w/c ratio
2
Increase of strength parameters through reduction of w/c ratio at constant slump flow
Types of concrete admixtures
Lignosulphonates – LS
Beta-Naphthalenesulphonate - Polycondensate – BNS
Melamine-Sulphonate-Poly-condensate – MFS
Poly Acrylates – PAC
Polycarboxylate Ethers - PCE
Traditional Plasticizers/Superplasticizers Mode of Action
Electrostatic Repulsion
BNS molecules
Mode of Action
1. Step: surface charges ( positive zeta potential) -O
cement grain
-O -O
O-
Ca2+ Ca2+
Ca2+
Ca2+
Ca2+
O-
Ca2+ Ca2+
Ca2+ Ca2+
-O
Ca2+
Ca2+
O-
Ca2+
Ca2+
Ca2+
Ca2+ Ca2+
Ca2+
Ca2+
Ca2+
O-
Ca2+
-O
Ca2+
Ca2+
formationCa Ca of positively charged Ca Ca Ca Ca Ca surfaces Ca
Ca2+
O-
2+
2+
2+
-O
2+
2+
2+
-O -O
O-
2+
2+
Ca2+ Ca2+ Ca2+ Ca2+
Ca2+
Ca2+
Ca2+
O-
Ca2+
Ca2+
O-
Ca2+
-O
Ca2+
Ca2+
Ca2+ Ca2+
OCa2+
Ca2+
-O
Ca2+
Ca2+
Ca2+
Ca2+
O-
cement grain
Ca2+
Mode of Action nd
step: adsorption of dispersants negatively functional negativelycharged charged functionalgroups groups 2+ Ca Oprovide providewater watersolubility solubilityand andaffinity affinityto to positively charged surfaces 2+ positively charged surfaces
O-
Ca
Ca -O -OCa
2+
2+ 2+ Ca
O-
Ca2+ -O
st nd addition OCa additionof of11stor or22ndgeneration generation (super-)plasticizers O(super-)plasticizers Ca 2+
-OCa
2+
2+
OCa e.g. e.g.lignin ligninsulfonates, sulfonates, naphthalene-sulfonatenaphthalene-sulfonate Ca O-O Ca formaldehyde formaldehyderesins resins Ca melamine-formaldehyde-sulfonate -O melamine-formaldehyde-sulfonate OCa resins resins OCa Ca -O 2+
Ca2+ -O 2+
2+
2+
2+
2+
Ca -O
2+
2+
2+ Ca
O-
cement grain
2+
-OCa
cement grain
2
Mode of Action th
4 step: loss of workability over time 2+ Ca
O-
2+
Loss Lossof ofdispersing dispersingeffect! effect!
cement grain
2+ Ca
-O -OCa
2+ Ca
O-
2+ 2+ Ca
O-
-O
Ca2+
2+ Ca
-O
Ca2+
OOCa 2+
2+ Ca
O-
Ca2+ -O
-OCa
2+
2+ Ca
O-
-OCa
2+
2+ Ca
-O
-OCa
2+
2+ Ca
Incorporation Incorporationof ofsuperplasticizers superplasticizers into intogrowing growinghydrate hydratephases phases
O-
2+ Ca
O-
2+ Ca
O-
cement grain
-OCa
Volume of Admixtures
Innovation History of Water Reducer Technology
AE high water-reducing agent Super plasticizer [Glenium] Conventional AE waterreducing agent [Pozzolith] High water-reducing agent [Rheobuild]
1950
1960
1970
1980 Year
1990
2000
2010
PCE Molecule
complex and flexible molecules, comprising of main chain Side chains functional groups.
PCE Based - GLENIUM Molecules
Electrostatic and Steric Repulsion GLENIUM molecules
Mode of Action
-OCa -OCa
cement grain
2+ 2+
2+ 2+
Introduction Introductionof of side sidechains chains
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
2+ Ca2+
-O
2+ 2+ Ca Ca
-O
2+ Ca2+
2+ Ca2+ -O
-OCa
2+ 2+
-OCa
2+ 2+
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
O-
2+ 2+
2+ 2+
polyether carboxylates Coulomb Coulomb Coulomb andonly! steric repulsion repulsion only! repulsion
2+ 2+
2+ 2+ Ca Ca
-OCa -OCa
st st generation: 1 21nd generation: generation:
O OCa Ca
more effective!
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
cement grain
2+ 2+
-OCa
Glenium Concrete
High grades Low Grades SCC Precast
Glenium Concrete for Higher Grades Why higher grades? (M45 – M 60)
Early destripping Advantages in column size reduction Longer spans and thinner decks PT slabs – 30 MPa in 3 days
General Practice for Higher Grade
Use of Higher Cement contents Use of very low water /cement ratios Use of Expensive Mineral Admixtures
Phenomenal increase in costs Concrete very sensitive to changes in moisture content Extra cement content due to retention effect
PT Slab requirements
30 MPa in 3 day
Constraint – Shrinkage, which is sensitive to use of higher cement content & SF
Large pours to be done Voids & honeycombs cannot be tolerated
Critical Areas
Use of higher cement content – Thermal Shrinkage Use of silica fume
– Risk of Plastic shrinkage
Use of low w/c ratio
– Higher dosage of SNF admixture – (retardation effect-plastic shrinkage)
Higher cost of concrete!
Hydration Reactions
Glenium Concrete
How does Glenium Work?
GLENIUMTM molecules
Improved Dispersion due to electrostatic and steric repulsion ….low w/cm
Glenium Concrete GLENIUM helps in
Excellent dispersion of binders Better Hydration Water reduction upto 40% Reduction in Cement content Lower risk to Thermal Shrinkage High early strengths Reduce/Eliminate SF Reasonably lower w/c ratios
Faster de-stripping possible Economical concrete Tolerant to changes in moisture content
M 60 Grade at a Site in Chennai
Typical Glenium Mix – M 60 Mix with SF
Mix with Glenium
Cement
430
425
Flyash
80
150
Silica Fume
35
0
565
575
Total Aggregates
1782
1722
Water
158
161
Traditional Admix
1.8%
xxx
Glenium Range
XXX
1.2%
W/B Ratio
0.28
0.28
1 Day
19.02
18.30
3 Days
39.46
37.40
7 Days
58.47
58.2
28 Days
72.34
71.11
Nil
Nil
Binder
Depth of water penetration
Economical Glenium Concrete Rs./Kg
Mix with SF
Mix With Glenium
Cement
4.25
1828
1806
Flyash
1.0
80
150
Silica fume
30
1050
0
Total Aggregates
0.40
713
689
Water
0.08
11
13
Trad. Admixture
50
509
0
Glenium Range
160
0
1120
4191
3778
Material Cost/Cu.M
Cost Saving ~ Rs. 400/M3
Glenium Concrete for Lower Grades
Requirements in Lower Grade concrete Early age strengths
Reduction in cement Addition of Fly ash Lower dosage of admixtures Extended retention – 2 to 3 hrs Avoid retempering of Concrete Tolerance to water (10 – 15 Litres)
Glenium Concrete GLENIUM helps in
Excellent dispersion of binders Better Hydration Reduction in Cement content Water reduction
Early Strength gain Addition of Flyash
lower w/c ratios
Economical concrete Tolerant to changes in water content
Typical Glenium Mix – M 30 Traditional M 30
Glenium Concrete
Cement
280
220
Flyash
60
120
340
340
Total Aggregates
1842
1820
Water
162
152
Traditional Admix
1.0%
xxx
Glenium Range Admixture
XXX
0.6%
W/B Ratio
0.46
0.42
1 Day
8.30
7.8
3 Days
16 .23
18.40
7 Days
26.42
28.92
28 Days
35.32
38.40
Binder
Economical Glenium Concrete Rs./Kg
Traditional
Mix With Glenium
Cement
4.25
1190
935
Flyash
1.0
60
120
Total Aggregates
0.40
737
728
Water
0.08
13
12
Trad. Admixture
28
95
0
Glenium Range
130
0
265
2095
2060
Material Cost/Cu.M
Shrinkage Reducing Admixture
TETRAGUARD®
PLASTIC SHRINKAGE DRYING SHRINKAGE THERMAL SHRINKAGE AUTOGENOUS SHRINKAGE CARBONATION SHRINKAGE
Drying Shrinkage Cracking Cause:
Volume reduction due to moisture loss Loss of moisture from freshly-hardened concrete Loss of moisture from concrete into sub-grade Joint
Drying Shrinkage
Sub-Base Inter-panel Cracking
Mechanism of Drying Shrinkage
Capillary Tension appears to be the dominant mechanism in drying shrinkage. Stress upon drying is related to the surface tension of pore water. Addition of SRA lowers the pore water surface tension.
How is Surface Tension Related to Drying Shrinkage?
Pore water loss due to hydration & evaporation.
As pores become less than fully saturated, meniscus forms at the air-water interface due to surface tension.
How is Surface Tension Related to Drying Shrinkage?
The surface tension of pore solution that forms meniscus also exerts inward pulling force on the side of the pore wall.
These forces in all pore sizes ranging from 2.5-50 nm is the primary cause of shrinkage.
Magnitude of Drying Shrinkage
28-Day
Typically 0.040-0.045% Range: 0.025-0.080% Long-Term
Typically 0.08%
(800 millionths or 800 microstrains) Range: Low: 0.04% High: 0.12%
Shrinkage-Reducing Admixtures
Developed in 1982 in Japan.
Primarily used as integral admixtures in concrete mixtures, but some can be applied topically to concrete surfaces.
Function by reducing capillary tension and the tensile forces that develop within the concrete pores as it dries.
Shrinkage-Reducing Admixtures TETRAGUARD shrinkage-reducing admixtures TETRAGUARD AS20 – Liquid form Offer a practical approach to combat drying shrinkage. Dosage: 0.5% - 4.0%, most typical dosage is 1-2%.
Designer and Producer Benefits
Reductions in drying shrinkage, drying shrinkage cracking and curling.
Elimination of extra reinforcement needed to restrain expansive forces.
No special silo or bag storage of Type K cement, expansive aids or aggregates
No increase in porosity due to microcracking Enhanced finishability and truck clean-up
Tetraguard AS 20 A new solution to an old problem: Reduced drying shrinkage cracking
0 -100 -200
Reduction of curling
µ strain
-300 -400 -500 -600 -700 -800 -900 -1000 0
100
200
300
400
Test Age (Days)
Reference
SRA
500
Burbank Water Treatment Facility, US
Design Considerations and Concerns for Liquid Containment Structure
Recommendations from ACI 350 for watertight structures were specified:
Maximized aggregate size, low w/c of 0.45, compressive strength of 28 MPa and drying shrinkage of 0.042% at 28 days.
Producer also needed pumpable mix with 18±2.5 cm slump for placement and consolidation around restraint and faced difficulties in meeting drying shrinkage specification with aggregates.
Concrete Mixture Proportions Burbank Water Treatment Facility Materials
Control
Mix 2
Mix 3
Mix 4
Type II Cement, kg/m3 Sand, kg/m3 3/8” Aggregate, kg/m3 1” Aggregate, kg/m3 Total Water, kg/m3 Water/Cement Ratio
383 761 197 845 172 0.45
383 761 197 845 172 0.45
383 761 197 845 172 0.45
383 761 197 845 172 0.45
Admixtures Superplasticizer, g/cwt Air Entrainer, g/cwt SRA, l/m3
142 11.3 0.0
142 11.3 2.5
142 11.3 3.7
142 11.3 5.0
Hardened Properties of Burbank Water Treatment Facility Mixtures
Mixture Reference Mixture 2 Mixture 3 Mixture 4
Average Compressive Strength (psi) 1-day 3-day 7-day 2340 4270 4740 2640 3770 5210 2670 4690 5100 2890 4650 5410
28-day 4900 5860 6210 6450
Average Length Change, % (negative sign denotes shrinkage) Mixture 7-day 14-day 21-day 28-day Reference -0.023 -0.033 -0.044 -0.049 Mixture 2 -0.011 -0.018 -0.027 -0.034 Mixture 3 -0.009 -0.014 -0.024 -0.028 Mixture 4 -0.007 -0.012 -0.020 -0.023
Comparison Testing of In situ and Laboratory Specimens
ASTM C157 Shrinkage Data from Laboratory and Field Specimens (µ µstrain) Reference Specimens Laboratory Average Field Average
28-day -663 -653
115-day -917 -870
320-day -1003 -950
474-day -1063 -1023
SRA Treated Specimens Laboratory Average Field Average
28-day -420 -370
115-day -630 -620
320-day -720 -700
474-day -777 -747
ASTM C 157 Shrinkage Data for Dupont Circle Full Depth Repair
L ength C hange (µ strain)
100 0 -100 -200 -300 -400 -500 -600 -700 -800 -900 -1000 -1100 -1200 0
50
100
150
200
250
300
350
400
450
500
Test Age (days)
Reference - Lab
Reference - Field
SRA - Lab
SRA - Field
In situ Shrinkage Data for Dupont Circle Full Depth Repair 0 -100 -200
µ strain
-300 -400 -500 -600 -700 -800 -900 -1000 0
100
200
300
400
Test Age (Days)
Reference
SRA
500
Shrinkage Reduction with SRA 60
ASTM C157 In situ
% Drying Shrinkage Reduction
50
40
30
20
10
0 28 Days
474 Days
Additional Findings
Enhanced Tensile Bond Strength Decreased Volume of Permeable Voids TETRGUARD addition did not effect set times Addition of TETRAGUARD at reduced restrained drying shrinkage in adverse simulated desert environments
Synergy with silica fume
Summary
SRAs provide significant reductions in drying shrinkage and subsequent cracking in both laboratory and field investigations.
Substantial benefits with regards to watertightness, aesthetics and overall serviceability can be obtained with SRAs.
Inclusion of SRAs to slabs, bridge decks, liquid containment and repair work can be very advantageous to improving life cycle.
Market of Ultra High-Strength Concrete Production Volume of RMC in Japan (2005)
Design Strength (Mpa/mm2)
Concrete Volume (×thousand m3)
Composition Ratio (%)
80＜
10
0.0
50-80
1,130
0.9
＜50
120,410
99.1
Total
121,550
100
A present market size is not so large. However, this technology is becoming a trend in Japan.
Why Ultra High-Strength Concrete? Trend of Architectural Design
1. To get wide-span by downsizing column 2. To get no-column living space for future renewal 3. To improve interior comfort by structural stiffness Larger Living Space
Small
Small
Large
Ultra High-Strength Concrete (UHSC) Typical Projects
Brillia Tower Tokyo Place: Kinshi-cho, Tokyo (45F, unit: 644) Owner: Tokyo Tatemono, completed in 2006 Constructor: TAISEI Corp. Fc130Mpa/mm2
THE KOSUGI TOWER Place: Kawasaki City, Kanagawa (49F, unit: 689) Owner: Tokyo Tatemono, completed by June of 2008 Constructor: TAISEI Corp. Fc150Mpa/mm2
Mix Design of UHSC Materials Cement:
Ordinary Port-land, Low heat, Silica fume premixed
Additive:
Silica fume (Powder type, Cement mixed type)
Aggregate:
Tight sands, Andesite crashed stone, sands
Admixture:
Superplasticizer for Ultra-High-Strength concrete
Fiber:
Polypropylene Fiber Cx5%
Cx3% Same condition W/C=15% Cement paste
Existing Product
RHEOBUILD SP8HU
Mix Design of UHSC Mix Design
Mix Design of Ultra High-Strength Concrete
Design No.
1)
Type of Cement
W/B (%)
W
C
Max.2
SF premixed
15.0
155
1033
(103)
2.5
65±10
Max.2
SF premixed
18.0
155
862
(86)
2.5
60±10
2±1.5
SF premixed
20.0
155
775
(78)
1.0
60±10
2±1.5
L + SF
20.0
155
697
78
1.0
60±10
2±1.5
SF premixed
30.0
155
517
-
1.0
60±10
2±1.5
M, L
25.0
170
680
-
1.0
Strength (Mpa)
Flow (cm)
Air (%)
1
150
65±10
2
130
3
100
4 5 6
80
Unit Weight (kg/m3)
Remarks 1) Type of Cement: L=Low-heat Portland Cement, M=Moderate-heat Portland Cement 2) SF: SF=Silica Fume
2)
SF
Fiber
Performance of Glenium 8008 Performance Requirements
1. Dispersibility of cement should be higher. 2. Mixing time should be shorter. 3. The viscosity of concrete should be lower. 4. Thixotropy of concrete should be lower. 5. It is necessary to make flowability change according to time smaller.
Performance of Glenium 8008 Dispersibility of cement Dispersibility of Glenium 8008 is higher than that of existing product.
SP dosage (Cx%)
3.5 3.0
Existing Product
2.5 2.0 1.5
Glenium 8008
1.0 12
14
16
18
20
22
24
Water-cement ratio (%)
26
Performance of Glenium 8008 Electric power consumption of Mixer （A)
Mixing Time
Existing Product SP8HU
+G Glenium 8008
+G
Discharge
Discharge
Existing Product
The improvement of dispersibility enables shortening the manufacturing time.
faster Mortal (W+AD+C+S)
Mortal +G
90sec
150sec Mortal (W+AD+C+S)
90sec
faster
Mortal +G
90sec
Hardened Property of UHSC Condition of Mix Design
Kind of binder
W/B
s/a
(%)
(%)
LS12
0.12
23.3
LS15
0.15
35.7
LPC+ SF
No.
LS18
0.18
41.9
LS22
0.22
46.6
L30
0.30
51.8
OP55
55.0
47.0
LPC OPC
Water (kg/m3)
150
Kind of admixture
Glenium 8008
160 176
AE water reducing
Air
Slump flow
content
(cm)
(%)
4.0
43.0
2.5
2.0
68.5
1.8
1.5
70.0
1.8
1.2
68.0
2.0
0.65
67.5
3.7
Dos. (Bx%)
250ml /B=100k g
Slump 19.0
4.5
Hardened Property of UHSC Compressive Strength Standard Curing Compressive strength (Mpa)
200
1year 28days
6months 7days
91days 1days
W/C=18% W/C=18%isisthe the highest highestMAX:170 MAX:170 56days Mpa Mpa
150
100
50
0 LS22
LS18
LS15
LS12
OP55
Hardened Property of UHSC Autogenous Shrinkage Age (day) Autogenous shrinkage strain (µ)
-28 0
28 56 84 112 140 168 196 224 252 280 308 336 364 392
200 0
L30
-200
LS18
-400 -600 -800 -1000 -1200
LS15
LS22
LS12
Hardened Property of UHSC Drying Shrinkage Age (week) Length changing ratio (%)
-10
0
10
20
30
40
0.00
-0.04
•• The The lower lower the the water-binder water-binder ratio, ratio, the the lower lower the the drying drying shrinkage shrinkage
-0.06 -0.08
-0.12
60
•• Drying Drying shrinkage shrinkage is is remarkably remarkably less less than than that that of of OP55 OP55
-0.02
-0.10
50
LS12
LS15
LS22
OP55
LS18
Admixtures for all Situations
High compressive strength Shrinkage Reduction Economical Concrete Water Tight Concrete Extended Haul Concretes Speedy Construction Impermeable Concrete Durable Concrete
Thank You!!
Contents 1
INTRODUCTION
2 GLENIUM CONCRETE 3 SHRINKAGE REDUCING CONCRETE 4 ULTRA HIGH STRENGTH CONCRETE 5 CONCLUSION
Admixtures?
What admixtures can do!
What Admixtures can do!
Chemical Admixtures
ASTM C 494
EN 934 – 2
IS 9103:2003
Chemical Admixtures Type
Description
A
Water Reducing admixture (WRA)
B
Retarding Admixture
C
Accelerating Admixture
D
Water Reducing & Retarding Admixture
E
Water Reducing & Accelerating Admixture
F
High Range Water Reducing Admixture (HRWRA)
G
High Range Water Reducing & Retarding Admix
Slump flow [cm]
Main effect of plasticizing admixtures
1
with Plasticizer 2
without Plasticizer Water/Cement Ratio
1
Higher workability at constant w/c ratio
2
Increase of strength parameters through reduction of w/c ratio at constant slump flow
Types of concrete admixtures
Lignosulphonates – LS
Beta-Naphthalenesulphonate - Polycondensate – BNS
Melamine-Sulphonate-Poly-condensate – MFS
Poly Acrylates – PAC
Polycarboxylate Ethers - PCE
Traditional Plasticizers/Superplasticizers Mode of Action
Electrostatic Repulsion
BNS molecules
Mode of Action
1. Step: surface charges ( positive zeta potential) -O
cement grain
-O -O
O-
Ca2+ Ca2+
Ca2+
Ca2+
Ca2+
O-
Ca2+ Ca2+
Ca2+ Ca2+
-O
Ca2+
Ca2+
O-
Ca2+
Ca2+
Ca2+
Ca2+ Ca2+
Ca2+
Ca2+
Ca2+
O-
Ca2+
-O
Ca2+
Ca2+
formationCa Ca of positively charged Ca Ca Ca Ca Ca surfaces Ca
Ca2+
O-
2+
2+
2+
-O
2+
2+
2+
-O -O
O-
2+
2+
Ca2+ Ca2+ Ca2+ Ca2+
Ca2+
Ca2+
Ca2+
O-
Ca2+
Ca2+
O-
Ca2+
-O
Ca2+
Ca2+
Ca2+ Ca2+
OCa2+
Ca2+
-O
Ca2+
Ca2+
Ca2+
Ca2+
O-
cement grain
Ca2+
Mode of Action nd
step: adsorption of dispersants negatively functional negativelycharged charged functionalgroups groups 2+ Ca Oprovide providewater watersolubility solubilityand andaffinity affinityto to positively charged surfaces 2+ positively charged surfaces
O-
Ca
Ca -O -OCa
2+
2+ 2+ Ca
O-
Ca2+ -O
st nd addition OCa additionof of11stor or22ndgeneration generation (super-)plasticizers O(super-)plasticizers Ca 2+
-OCa
2+
2+
OCa e.g. e.g.lignin ligninsulfonates, sulfonates, naphthalene-sulfonatenaphthalene-sulfonate Ca O-O Ca formaldehyde formaldehyderesins resins Ca melamine-formaldehyde-sulfonate -O melamine-formaldehyde-sulfonate OCa resins resins OCa Ca -O 2+
Ca2+ -O 2+
2+
2+
2+
2+
Ca -O
2+
2+
2+ Ca
O-
cement grain
2+
-OCa
cement grain
2
Mode of Action th
4 step: loss of workability over time 2+ Ca
O-
2+
Loss Lossof ofdispersing dispersingeffect! effect!
cement grain
2+ Ca
-O -OCa
2+ Ca
O-
2+ 2+ Ca
O-
-O
Ca2+
2+ Ca
-O
Ca2+
OOCa 2+
2+ Ca
O-
Ca2+ -O
-OCa
2+
2+ Ca
O-
-OCa
2+
2+ Ca
-O
-OCa
2+
2+ Ca
Incorporation Incorporationof ofsuperplasticizers superplasticizers into intogrowing growinghydrate hydratephases phases
O-
2+ Ca
O-
2+ Ca
O-
cement grain
-OCa
Volume of Admixtures
Innovation History of Water Reducer Technology
AE high water-reducing agent Super plasticizer [Glenium] Conventional AE waterreducing agent [Pozzolith] High water-reducing agent [Rheobuild]
1950
1960
1970
1980 Year
1990
2000
2010
PCE Molecule
complex and flexible molecules, comprising of main chain Side chains functional groups.
PCE Based - GLENIUM Molecules
Electrostatic and Steric Repulsion GLENIUM molecules
Mode of Action
-OCa -OCa
cement grain
2+ 2+
2+ 2+
Introduction Introductionof of side sidechains chains
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
2+ Ca2+
-O
2+ 2+ Ca Ca
-O
2+ Ca2+
2+ Ca2+ -O
-OCa
2+ 2+
-OCa
2+ 2+
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
O-
2+ 2+
2+ 2+
polyether carboxylates Coulomb Coulomb Coulomb andonly! steric repulsion repulsion only! repulsion
2+ 2+
2+ 2+ Ca Ca
-OCa -OCa
st st generation: 1 21nd generation: generation:
O OCa Ca
more effective!
2+ 2+ Ca Ca
O-
2+ 2+ Ca Ca
O-
cement grain
2+ 2+
-OCa
Glenium Concrete
High grades Low Grades SCC Precast
Glenium Concrete for Higher Grades Why higher grades? (M45 – M 60)
Early destripping Advantages in column size reduction Longer spans and thinner decks PT slabs – 30 MPa in 3 days
General Practice for Higher Grade
Use of Higher Cement contents Use of very low water /cement ratios Use of Expensive Mineral Admixtures
Phenomenal increase in costs Concrete very sensitive to changes in moisture content Extra cement content due to retention effect
PT Slab requirements
30 MPa in 3 day
Constraint – Shrinkage, which is sensitive to use of higher cement content & SF
Large pours to be done Voids & honeycombs cannot be tolerated
Critical Areas
Use of higher cement content – Thermal Shrinkage Use of silica fume
– Risk of Plastic shrinkage
Use of low w/c ratio
– Higher dosage of SNF admixture – (retardation effect-plastic shrinkage)
Higher cost of concrete!
Hydration Reactions
Glenium Concrete
How does Glenium Work?
GLENIUMTM molecules
Improved Dispersion due to electrostatic and steric repulsion ….low w/cm
Glenium Concrete GLENIUM helps in
Excellent dispersion of binders Better Hydration Water reduction upto 40% Reduction in Cement content Lower risk to Thermal Shrinkage High early strengths Reduce/Eliminate SF Reasonably lower w/c ratios
Faster de-stripping possible Economical concrete Tolerant to changes in moisture content
M 60 Grade at a Site in Chennai
Typical Glenium Mix – M 60 Mix with SF
Mix with Glenium
Cement
430
425
Flyash
80
150
Silica Fume
35
0
565
575
Total Aggregates
1782
1722
Water
158
161
Traditional Admix
1.8%
xxx
Glenium Range
XXX
1.2%
W/B Ratio
0.28
0.28
1 Day
19.02
18.30
3 Days
39.46
37.40
7 Days
58.47
58.2
28 Days
72.34
71.11
Nil
Nil
Binder
Depth of water penetration
Economical Glenium Concrete Rs./Kg
Mix with SF
Mix With Glenium
Cement
4.25
1828
1806
Flyash
1.0
80
150
Silica fume
30
1050
0
Total Aggregates
0.40
713
689
Water
0.08
11
13
Trad. Admixture
50
509
0
Glenium Range
160
0
1120
4191
3778
Material Cost/Cu.M
Cost Saving ~ Rs. 400/M3
Glenium Concrete for Lower Grades
Requirements in Lower Grade concrete Early age strengths
Reduction in cement Addition of Fly ash Lower dosage of admixtures Extended retention – 2 to 3 hrs Avoid retempering of Concrete Tolerance to water (10 – 15 Litres)
Glenium Concrete GLENIUM helps in
Excellent dispersion of binders Better Hydration Reduction in Cement content Water reduction
Early Strength gain Addition of Flyash
lower w/c ratios
Economical concrete Tolerant to changes in water content
Typical Glenium Mix – M 30 Traditional M 30
Glenium Concrete
Cement
280
220
Flyash
60
120
340
340
Total Aggregates
1842
1820
Water
162
152
Traditional Admix
1.0%
xxx
Glenium Range Admixture
XXX
0.6%
W/B Ratio
0.46
0.42
1 Day
8.30
7.8
3 Days
16 .23
18.40
7 Days
26.42
28.92
28 Days
35.32
38.40
Binder
Economical Glenium Concrete Rs./Kg
Traditional
Mix With Glenium
Cement
4.25
1190
935
Flyash
1.0
60
120
Total Aggregates
0.40
737
728
Water
0.08
13
12
Trad. Admixture
28
95
0
Glenium Range
130
0
265
2095
2060
Material Cost/Cu.M
Shrinkage Reducing Admixture
TETRAGUARD®
PLASTIC SHRINKAGE DRYING SHRINKAGE THERMAL SHRINKAGE AUTOGENOUS SHRINKAGE CARBONATION SHRINKAGE
Drying Shrinkage Cracking Cause:
Volume reduction due to moisture loss Loss of moisture from freshly-hardened concrete Loss of moisture from concrete into sub-grade Joint
Drying Shrinkage
Sub-Base Inter-panel Cracking
Mechanism of Drying Shrinkage
Capillary Tension appears to be the dominant mechanism in drying shrinkage. Stress upon drying is related to the surface tension of pore water. Addition of SRA lowers the pore water surface tension.
How is Surface Tension Related to Drying Shrinkage?
Pore water loss due to hydration & evaporation.
As pores become less than fully saturated, meniscus forms at the air-water interface due to surface tension.
How is Surface Tension Related to Drying Shrinkage?
The surface tension of pore solution that forms meniscus also exerts inward pulling force on the side of the pore wall.
These forces in all pore sizes ranging from 2.5-50 nm is the primary cause of shrinkage.
Magnitude of Drying Shrinkage
28-Day
Typically 0.040-0.045% Range: 0.025-0.080% Long-Term
Typically 0.08%
(800 millionths or 800 microstrains) Range: Low: 0.04% High: 0.12%
Shrinkage-Reducing Admixtures
Developed in 1982 in Japan.
Primarily used as integral admixtures in concrete mixtures, but some can be applied topically to concrete surfaces.
Function by reducing capillary tension and the tensile forces that develop within the concrete pores as it dries.
Shrinkage-Reducing Admixtures TETRAGUARD shrinkage-reducing admixtures TETRAGUARD AS20 – Liquid form Offer a practical approach to combat drying shrinkage. Dosage: 0.5% - 4.0%, most typical dosage is 1-2%.
Designer and Producer Benefits
Reductions in drying shrinkage, drying shrinkage cracking and curling.
Elimination of extra reinforcement needed to restrain expansive forces.
No special silo or bag storage of Type K cement, expansive aids or aggregates
No increase in porosity due to microcracking Enhanced finishability and truck clean-up
Tetraguard AS 20 A new solution to an old problem: Reduced drying shrinkage cracking
0 -100 -200
Reduction of curling
µ strain
-300 -400 -500 -600 -700 -800 -900 -1000 0
100
200
300
400
Test Age (Days)
Reference
SRA
500
Burbank Water Treatment Facility, US
Design Considerations and Concerns for Liquid Containment Structure
Recommendations from ACI 350 for watertight structures were specified:
Maximized aggregate size, low w/c of 0.45, compressive strength of 28 MPa and drying shrinkage of 0.042% at 28 days.
Producer also needed pumpable mix with 18±2.5 cm slump for placement and consolidation around restraint and faced difficulties in meeting drying shrinkage specification with aggregates.
Concrete Mixture Proportions Burbank Water Treatment Facility Materials
Control
Mix 2
Mix 3
Mix 4
Type II Cement, kg/m3 Sand, kg/m3 3/8” Aggregate, kg/m3 1” Aggregate, kg/m3 Total Water, kg/m3 Water/Cement Ratio
383 761 197 845 172 0.45
383 761 197 845 172 0.45
383 761 197 845 172 0.45
383 761 197 845 172 0.45
Admixtures Superplasticizer, g/cwt Air Entrainer, g/cwt SRA, l/m3
142 11.3 0.0
142 11.3 2.5
142 11.3 3.7
142 11.3 5.0
Hardened Properties of Burbank Water Treatment Facility Mixtures
Mixture Reference Mixture 2 Mixture 3 Mixture 4
Average Compressive Strength (psi) 1-day 3-day 7-day 2340 4270 4740 2640 3770 5210 2670 4690 5100 2890 4650 5410
28-day 4900 5860 6210 6450
Average Length Change, % (negative sign denotes shrinkage) Mixture 7-day 14-day 21-day 28-day Reference -0.023 -0.033 -0.044 -0.049 Mixture 2 -0.011 -0.018 -0.027 -0.034 Mixture 3 -0.009 -0.014 -0.024 -0.028 Mixture 4 -0.007 -0.012 -0.020 -0.023
Comparison Testing of In situ and Laboratory Specimens
ASTM C157 Shrinkage Data from Laboratory and Field Specimens (µ µstrain) Reference Specimens Laboratory Average Field Average
28-day -663 -653
115-day -917 -870
320-day -1003 -950
474-day -1063 -1023
SRA Treated Specimens Laboratory Average Field Average
28-day -420 -370
115-day -630 -620
320-day -720 -700
474-day -777 -747
ASTM C 157 Shrinkage Data for Dupont Circle Full Depth Repair
L ength C hange (µ strain)
100 0 -100 -200 -300 -400 -500 -600 -700 -800 -900 -1000 -1100 -1200 0
50
100
150
200
250
300
350
400
450
500
Test Age (days)
Reference - Lab
Reference - Field
SRA - Lab
SRA - Field
In situ Shrinkage Data for Dupont Circle Full Depth Repair 0 -100 -200
µ strain
-300 -400 -500 -600 -700 -800 -900 -1000 0
100
200
300
400
Test Age (Days)
Reference
SRA
500
Shrinkage Reduction with SRA 60
ASTM C157 In situ
% Drying Shrinkage Reduction
50
40
30
20
10
0 28 Days
474 Days
Additional Findings
Enhanced Tensile Bond Strength Decreased Volume of Permeable Voids TETRGUARD addition did not effect set times Addition of TETRAGUARD at reduced restrained drying shrinkage in adverse simulated desert environments
Synergy with silica fume
Summary
SRAs provide significant reductions in drying shrinkage and subsequent cracking in both laboratory and field investigations.
Substantial benefits with regards to watertightness, aesthetics and overall serviceability can be obtained with SRAs.
Inclusion of SRAs to slabs, bridge decks, liquid containment and repair work can be very advantageous to improving life cycle.
Market of Ultra High-Strength Concrete Production Volume of RMC in Japan (2005)
Design Strength (Mpa/mm2)
Concrete Volume (×thousand m3)
Composition Ratio (%)
80＜
10
0.0
50-80
1,130
0.9
＜50
120,410
99.1
Total
121,550
100
A present market size is not so large. However, this technology is becoming a trend in Japan.
Why Ultra High-Strength Concrete? Trend of Architectural Design
1. To get wide-span by downsizing column 2. To get no-column living space for future renewal 3. To improve interior comfort by structural stiffness Larger Living Space
Small
Small
Large
Ultra High-Strength Concrete (UHSC) Typical Projects
Brillia Tower Tokyo Place: Kinshi-cho, Tokyo (45F, unit: 644) Owner: Tokyo Tatemono, completed in 2006 Constructor: TAISEI Corp. Fc130Mpa/mm2
THE KOSUGI TOWER Place: Kawasaki City, Kanagawa (49F, unit: 689) Owner: Tokyo Tatemono, completed by June of 2008 Constructor: TAISEI Corp. Fc150Mpa/mm2
Mix Design of UHSC Materials Cement:
Ordinary Port-land, Low heat, Silica fume premixed
Additive:
Silica fume (Powder type, Cement mixed type)
Aggregate:
Tight sands, Andesite crashed stone, sands
Admixture:
Superplasticizer for Ultra-High-Strength concrete
Fiber:
Polypropylene Fiber Cx5%
Cx3% Same condition W/C=15% Cement paste
Existing Product
RHEOBUILD SP8HU
Mix Design of UHSC Mix Design
Mix Design of Ultra High-Strength Concrete
Design No.
1)
Type of Cement
W/B (%)
W
C
Max.2
SF premixed
15.0
155
1033
(103)
2.5
65±10
Max.2
SF premixed
18.0
155
862
(86)
2.5
60±10
2±1.5
SF premixed
20.0
155
775
(78)
1.0
60±10
2±1.5
L + SF
20.0
155
697
78
1.0
60±10
2±1.5
SF premixed
30.0
155
517
-
1.0
60±10
2±1.5
M, L
25.0
170
680
-
1.0
Strength (Mpa)
Flow (cm)
Air (%)
1
150
65±10
2
130
3
100
4 5 6
80
Unit Weight (kg/m3)
Remarks 1) Type of Cement: L=Low-heat Portland Cement, M=Moderate-heat Portland Cement 2) SF: SF=Silica Fume
2)
SF
Fiber
Performance of Glenium 8008 Performance Requirements
1. Dispersibility of cement should be higher. 2. Mixing time should be shorter. 3. The viscosity of concrete should be lower. 4. Thixotropy of concrete should be lower. 5. It is necessary to make flowability change according to time smaller.
Performance of Glenium 8008 Dispersibility of cement Dispersibility of Glenium 8008 is higher than that of existing product.
SP dosage (Cx%)
3.5 3.0
Existing Product
2.5 2.0 1.5
Glenium 8008
1.0 12
14
16
18
20
22
24
Water-cement ratio (%)
26
Performance of Glenium 8008 Electric power consumption of Mixer （A)
Mixing Time
Existing Product SP8HU
+G Glenium 8008
+G
Discharge
Discharge
Existing Product
The improvement of dispersibility enables shortening the manufacturing time.
faster Mortal (W+AD+C+S)
Mortal +G
90sec
150sec Mortal (W+AD+C+S)
90sec
faster
Mortal +G
90sec
Hardened Property of UHSC Condition of Mix Design
Kind of binder
W/B
s/a
(%)
(%)
LS12
0.12
23.3
LS15
0.15
35.7
LPC+ SF
No.
LS18
0.18
41.9
LS22
0.22
46.6
L30
0.30
51.8
OP55
55.0
47.0
LPC OPC
Water (kg/m3)
150
Kind of admixture
Glenium 8008
160 176
AE water reducing
Air
Slump flow
content
(cm)
(%)
4.0
43.0
2.5
2.0
68.5
1.8
1.5
70.0
1.8
1.2
68.0
2.0
0.65
67.5
3.7
Dos. (Bx%)
250ml /B=100k g
Slump 19.0
4.5
Hardened Property of UHSC Compressive Strength Standard Curing Compressive strength (Mpa)
200
1year 28days
6months 7days
91days 1days
W/C=18% W/C=18%isisthe the highest highestMAX:170 MAX:170 56days Mpa Mpa
150
100
50
0 LS22
LS18
LS15
LS12
OP55
Hardened Property of UHSC Autogenous Shrinkage Age (day) Autogenous shrinkage strain (µ)
-28 0
28 56 84 112 140 168 196 224 252 280 308 336 364 392
200 0
L30
-200
LS18
-400 -600 -800 -1000 -1200
LS15
LS22
LS12
Hardened Property of UHSC Drying Shrinkage Age (week) Length changing ratio (%)
-10
0
10
20
30
40
0.00
-0.04
•• The The lower lower the the water-binder water-binder ratio, ratio, the the lower lower the the drying drying shrinkage shrinkage
-0.06 -0.08
-0.12
60
•• Drying Drying shrinkage shrinkage is is remarkably remarkably less less than than that that of of OP55 OP55
-0.02
-0.10
50
LS12
LS15
LS22
OP55
LS18
Admixtures for all Situations
High compressive strength Shrinkage Reduction Economical Concrete Water Tight Concrete Extended Haul Concretes Speedy Construction Impermeable Concrete Durable Concrete
Thank You!!
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