Influence of Soil and Binder Properties on the Efficacy of ... - Starnet

<strong>Influence</strong> <strong>of</strong> <strong>Soil</strong> <strong>and</strong> <strong>Binder</strong> <strong>Properties</strong> on
the Efficacy <strong>of</strong> Accelerated Carbonation
L. H. Barnard, D. I. Boardman & C. D. F. Rogers
The University <strong>of</strong> Birmingham
C. D. Hills, P. J. Carey, K. Canning & C. L. MacLeod
The University <strong>of</strong> Greenwich
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Presentation Overview
Accelerated Carbonation Process
Objectives <strong>of</strong> the Research
Research Methodology
Results <strong>and</strong> Conclusions.
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Accelerated Carbonation
Accelerated Carbonation incorporates an additional step into the
S/S process, introducing carbon dioxide gas either during mixing
with the binder or immediately thereafter
Ex-situ application
CO 2 added in a confined environment during mixing
Rapid reaction in minutes
Exothermic reaction.
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Research Objectives
To investigate the effect <strong>of</strong>
• soil type
• binder type
• binder content <strong>and</strong>
• water content
on the uptake <strong>of</strong> CO 2 during accelerated carbonation.
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Methodology
CO 2 uptake measured
10 different binders
11 different soil types
<strong>Binder</strong> concentrations <strong>of</strong> 5% 10% 20%
Water:solid ratio 0.2.
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Carbonation
Method
Gas
Control
Tap
Gas Tight Lid
Pressure
Gauge
Gas
In
Saturated
NaCl
Solution
Samples
Gas
Out
Samples:
100g soil + binder
Deionised water
Water content 0.2
Each sample divided in 2
100% CO 2 atmosphere
Pressure 300 kPa
24 hours
Static chamber
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Carbonation Index &
Carbonation Capacity
% CO2
8
7
6
5
4
3
2
1
0
CARBONATION INDEX
CO 2 (THEORY)
CO 2 (CAPACITY)
CO 2 (CARB)
CO 2 (NON-CARB)
0.15 0.2 0.25 0.3
Water:Solid Ratio
Carbonation Index = CO 2 (CARB) –CO 2 (NON-CARB)
Carbonation Capacity = CO 2 (THEORY) –CO 2 (NON-CARB)
CO 2 (THEORY) = 0.785(CaO – 0.7SO 3
) + 1.091MgO + 1.420Na 2
O + 0.935K 2
O
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Effect <strong>of</strong> Variation <strong>of</strong> Water
Content
Carbonation Index (% CO2 )
20
18
16
14
12
10
8
6
4
2
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35
Water: Solid Ratio
S<strong>and</strong> + 10% <strong>Binder</strong> 1 100% <strong>Binder</strong> 1
Variation <strong>of</strong> different
soil types
High binder contents
more critical?
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OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Effect <strong>of</strong> Surface Area <strong>of</strong> <strong>Binder</strong>
Carbonation Index (% (% CO
CO 2)
2 )
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 5 10 15 20
<strong>Binder</strong> (% by mass)
<strong>Binder</strong> 1 <strong>Binder</strong> 2 <strong>Binder</strong> 3 <strong>Binder</strong> 4
<strong>Binder</strong> 5 <strong>Binder</strong> 6 <strong>Binder</strong> 7
<strong>Binder</strong> 1 350 m 2 /kg
<strong>Binder</strong> 2 625-675 m 2 /kg
THE UNIVERSITY
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the
UNIVERSITY
<strong>of</strong>
GREENWICH

Effect <strong>of</strong> Composition <strong>of</strong> <strong>Binder</strong>
2)
Carbonation Index (% CO
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 5 10 15 20
<strong>Binder</strong> (% by mass)
<strong>Binder</strong> 1 <strong>Binder</strong> 2 <strong>Binder</strong> 3
<strong>Binder</strong> 4 <strong>Binder</strong> 5 <strong>Binder</strong> 6
CaO %
1 63.0
2 62.2
6 63.8
4 59.1
5 48.4
3 36.3
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UNIVERSITY
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Effect <strong>of</strong> Composition <strong>of</strong> <strong>Binder</strong>
7
Carbonation Index (% CO2 )
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
CO 2 Capacity (% CO 2 )
<strong>Binder</strong> 1 <strong>Binder</strong> 2 <strong>Binder</strong> 3
<strong>Binder</strong> 4 <strong>Binder</strong> 5 <strong>Binder</strong> 6
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UNIVERSITY
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Effect <strong>of</strong> Mineralogy on the
Finer Grained <strong>Soil</strong>s
4.5
Carbonation Index (% CO2 )
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 5 10 15 20
<strong>Binder</strong> (% by mass)
Bentonite Greens<strong>and</strong> Lambeth S<strong>and</strong>
Loess London Clay China Clay
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UNIVERSITY
<strong>of</strong>
GREENWICH

Effect <strong>of</strong> Particle Size Distribution
<strong>of</strong> <strong>Soil</strong>s
4.5
Carbonation Index (% CO
2 )
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 5 10 15 20
<strong>Binder</strong> (% by mass)
Bentonite Greens<strong>and</strong> Lambeth S<strong>and</strong>
Loess London Clay China Clay
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Conclusions
Water content affects uptake – high binder contents
<strong>Binder</strong> composition – oxide content & CaAl / CaSi based
<strong>Binder</strong> surface area
Mineralogy <strong>of</strong> finer grained soils
Limiting mechanism at higher binder contents
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

<strong>Influence</strong> <strong>of</strong> <strong>Soil</strong> <strong>and</strong> <strong>Binder</strong> <strong>Properties</strong> on
the Efficacy <strong>of</strong> Accelerated Carbonation
L. H. Barnard, D. I. Boardman & C. D. F. Rogers
The University <strong>of</strong> Birmingham
C. D. Hills, P. J. Carey, K. Canning & C. L. MacLeod
The University <strong>of</strong> Greenwich
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH

Particle Size Distribution <strong>of</strong> <strong>Soil</strong>s
100
90
80
70
% Passing
60
50
40
30
20
10
0
0.0000 0.0001 0.0010 0.0100 0.1000 1.0000 10.0000 100.0000
Sieve Size (mm)
S<strong>and</strong> Lambeth S<strong>and</strong> Greens<strong>and</strong> Bentonite English China Clay Loess London Clay
THE UNIVERSITY
OF BIRMINGHAM
the
UNIVERSITY
<strong>of</strong>
GREENWICH