2016 MES Winter Meeting
47
Internal Curin wi Fine Lightweig Donald M. Smith, Donald M. Smith, Adam Browne, PE ng of Concrete ith ght Aggregates PhD, PE, Consultant PhD, PE, Consultant E, MDOT
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Transcript of 2016 MES Winter Meeting
Internal Curing of Concrete
with
Fine Lightweight Aggregates
Donald M. Smith, PhD, Donald M. Smith, PhD,
Adam Browne, PE, MDOT
Internal Curing of Concrete
with
Fine Lightweight Aggregates
Donald M. Smith, PhD, PE, ConsultantDonald M. Smith, PhD, PE, Consultant
Adam Browne, PE, MDOT
Senior Engineer
• 36 years experience in transportation facilities, engineering materials, geotechnical engineering, pavements engineering, construction and laboratory testing.
• Expertise in the design, analysis, maintenance, management, and rehabilitation of rigid, flexible, low volume and unsurfaced pavements and materials
Donald Mark Smith, Ph.D., P.E.Education
Bachelor of Science,1983, Civil
EngineeringMississippi State
University
Master of Science, 1990, Civil
Engineering, Mississippi State
• Registered Professional Engineer, Mississippi
Mississippi State University
Doctor of Philosophy 2000, Civil
Engineering, Louisiana State
University
experience in transportation facilities, engineering materials, geotechnical engineering, pavements engineering, construction and laboratory testing.
Expertise in the design, analysis, maintenance, management, and rehabilitation of rigid, flexible, low volume and unsurfaced pavements and materials
Donald Mark Smith, Ph.D., P.E.
Registered Professional Engineer, Mississippi
Engineer
• 15 years experience in transportation facilities, engineering materials, construction,
• Expertise in concrete mixtures, concrete durability,
Adam Browne,
Education
Bachelor of Science,1996, Mechanical
EngineeringMississippi State
University • Expertise in concrete mixtures, concrete durability, cementitious materials
• Registered Professional Engineer,
University
15 years experience in transportation facilities, engineering construction, and laboratory testing.
concrete mixtures, concrete durability,
Adam Browne, P.E.
concrete mixtures, concrete durability, cementitious materials
Registered Professional Engineer, Mississippi
Let’s Start from the Beginning:
1. Portland Cement Concrete
2. Fine Lightweight Aggregates2. Fine Lightweight Aggregates
3. Internal Curing
Let’s Start from the Beginning:
1. Portland Cement Concrete
2. Fine Lightweight Aggregates2. Fine Lightweight Aggregates
Portland Cement
Concrete ...........Concrete ...........
Portland Cement
Concrete ...........Concrete ...........
One Definition of Portland Cement Concrete…
• Portland cement concrete (PCC) is a heterogeneous system of solid, discrete, gradiently sized, inorganic mineral aggregates, usually plutonic or sedimentary-calcareous in origin, embedded in a matrix compounded of synthesized polybasic alkaline and alkaloidal silicates held in aqueous solution and co-precipitate dispersion with other amphoteric oxides, this matrix being originally capable of progressive dissolution, hydration, re-precipitation, gelation and solidification through a continuous and re-precipitation, gelation and solidification through a continuous and co-existent series of crystalline, amorphous, colloidal and cryptocrystalline states and ultimately subject to thermoallotriomorphic alteration, the system when first conjoined being plastic during which stage it is impressed to a predetermined form into which it finally consolidates, thus providing a structure relatively impermeable and with useful capacity to transmit tensile, compressive, and shear stresses.
•(source unknown)
One Definition of Portland Cement Concrete…
Portland cement concrete (PCC) is a heterogeneous system of solid, sized, inorganic mineral aggregates, usually plutonic
calcareous in origin, embedded in a matrix compounded of synthesized polybasic alkaline and alkaloidal silicates held in aqueous
precipitate dispersion with other amphoteric oxides, this matrix being originally capable of progressive dissolution, hydration,
precipitation, gelation and solidification through a continuous and precipitation, gelation and solidification through a continuous and existent series of crystalline, amorphous, colloidal and
cryptocrystalline states and ultimately subject to thermo-alteration, the system when first conjoined being plastic
during which stage it is impressed to a predetermined form into which it finally consolidates, thus providing a structure relatively impermeable and with useful capacity to transmit tensile, compressive, and shear
One Definition of Portland Cement Concrete…
• Portland cement concrete (PCC) is a heterogeneous system of solid, discrete, gradiently sized, inorganic mineral aggregates, usually plutonic or sedimentary-calcareous in origin, embedded in a matrix compounded of synthesized polybasic alkaline and alkaloidal silicates held in aqueous solution and co-precipitate dispersion with other amphoteric oxides, this matrix being originally capable of progressive dissolution, hydration, re-precipitation, gelation and solidification through a continuous and
?...........re-precipitation, gelation and solidification through a continuous and co-existent series of crystalline, amorphous, colloidal and cryptocrystalline states and ultimately subject to thermoallotriomorphic alteration, the system when first conjoined being plastic during which stage it is impressed to a predetermined form into which it finally consolidates, thus providing a structure relatively impermeable and with useful capacity to transmit tensile, compressive, and shear stresses.
•(source unknown)
?...........
One Definition of Portland Cement Concrete…
Portland cement concrete (PCC) is a heterogeneous system of solid, sized, inorganic mineral aggregates, usually plutonic
calcareous in origin, embedded in a matrix compounded of synthesized polybasic alkaline and alkaloidal silicates held in aqueous
precipitate dispersion with other amphoteric oxides, this matrix being originally capable of progressive dissolution, hydration,
precipitation, gelation and solidification through a continuous and
?...........precipitation, gelation and solidification through a continuous and existent series of crystalline, amorphous, colloidal and
cryptocrystalline states and ultimately subject to thermo-alteration, the system when first conjoined being plastic
during which stage it is impressed to a predetermined form into which it finally consolidates, thus providing a structure relatively impermeable and with useful capacity to transmit tensile, compressive, and shear
?...........
A Real Definition of PCC…
• A mixture of:
• Portland Cement
• Fine Aggregate
• Coarse Aggregate
• Water• Water
• Air
• Cement and water combine, changing from a moist, plastic consistency to a strong, durable rock-like construction material by means of a chemical reaction called “hydration”
A Real Definition of PCC…
Cement and water combine,
means of a chemical reaction
Further Defined…
• Concrete exists in three states
• Plastic
• Curing
• Hardened
Even deeper down the rabbit hole…
Curing is both a state and an 1. Concrete’s state during the transformation from a plastic
heterogeneous mixture to a hardened heterogeneous
mixture.
2. The actions taken to ensure the moisture and temperature
conditions exist during the transformation from a plastic
state to a hardened state so that the concrete may fully state to a hardened state so that the concrete may fully
develop its potential properties.
Even deeper down the rabbit hole…
Curing is both a state and an action:Concrete’s state during the transformation from a plastic
heterogeneous mixture to a hardened heterogeneous
The actions taken to ensure the moisture and temperature
conditions exist during the transformation from a plastic
state to a hardened state so that the concrete may fully state to a hardened state so that the concrete may fully
develop its potential properties.
Drying
Cement hydration = self-
Wet CuringDrying
-desiccation
Internal Curing ...........Internal Curing ...........Internal Curing ...........Internal Curing ...........
A definition of Internal Curing“the process by which the hydration of cement continues because of the availability
of internal water that is not part of the mixing water
Co
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Inte
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rvo
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Radlinska et al.
Transportation Research Record: Journal of the Transportation Research Board,
No. 2070, Transportation Research Board of the National Academies, Washington,
D.C., 2008, pp. 59–67.
Co
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on
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Inte
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rvo
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A definition of Internal Curingprocess by which the hydration of cement continues because of the availability
of internal water that is not part of the mixing water.“
- ACI Committee 308, Curing Concrete
Co
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on
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Fine Lightweight
Aggregates ..........Aggregates ..........
Fine Lightweight
Aggregates ..........Aggregates ..........
http://www.checkyourodds.co.uk/boxing/bett-boxing.php
http://totallyhistory.com/evander-holyfield/
What do we mean by “lightweight”?mma/pacquiao-honoured-as-best-of-
http://w
ww.dailytelegraph.com.au/sport/boxing-m
ma/pacquiao
decade/story-e6freygr-1225825737810
Manny Pacquiao
What do we mean by “lightweight”?
http://w
ww.cleveland.com/sports/index.ssf/2011/01/evander_holyfield_still_looks.htm
l
Evander Holyfield
http://w
ww.cleveland.com/sports/index.ssf/2011/01/evander_holyfield_still_looks.htm
l
A definition of “lightweight aggregate”Lightweight aggregate is an “aggregate made by heating clay [shale or slate] to around 1,200
(2,190 °F) in a rotary kiln. The yielding gases expand
bubbles forming during heating producing a honeycomb structure.”
They “contain a uniformly distributed system of pores that have a size range of approximately 5 to
300μm.”
http://lolclassic.com/?w=TD90WfoPvh8&title=jim-braddock-vs-joe-louis-all-rounds-part-22
300μm.”
A definition of “lightweight aggregate”is an “aggregate made by heating clay [shale or slate] to around 1,200 °C
F) in a rotary kiln. The yielding gases expand the clay [shale or slate] by thousands of small
bubbles forming during heating producing a honeycomb structure.”https://en.wikipedia.org/wiki/Expanded_clay_aggregate
a uniformly distributed system of pores that have a size range of approximately 5 to
http://www.cptechcenter.org/ncc/TTCC-NCC-documents/Sp2014/SP14-22-Weiss-Internal%20Curing
http://www.escsi.org/ContentPage.aspx?id=53
How Internal Curing is accomplished by LWA
Water is released from water-filled
aggregate (LWA) when it is used for I
the IC water needs to be described in
1. the ability of the water to leave the LWA when needed for 1. the ability of the water to leave the LWA when needed for
2. the volume of water available for IC,
3. the distribution of the LWA so that it is well
water can readily travel to all of
is needed.
How Internal Curing is accomplished by LWA
filled pre-wetted lightweight
it is used for Internal Curing (IC). As such,
described in three main ways:
the ability of the water to leave the LWA when needed for IC,the ability of the water to leave the LWA when needed for IC,
volume of water available for IC,
so that it is well-dispersed and its
water can readily travel to all of the sections in the paste where it
1. the ability of the water to leave the LWA
Material properties of the LWA:% Absorption – how much water
can it readily contain
http://trinitylightweight.com/index.php/applications
curing
can it readily contain
% Desorption – how much water
will it readily give up
ability of the water to leave the LWA
2. the volume of water available for IC
Mass of Lightweight Aggregate Required (lb/CY)
Cement Factor (lb/CY)
Chemical Shrinkage of cement (lb H2O / 100 lb
Degree of Hydration
Absorption of LWA (%)
Desorption of LWA (%)
volume of water available for IC
Amount of water required to replenish
water absorbed by cement
Factors for compensating for LWA Absorption
and Desorption
http://trinitylightw
eight.com/index.php/applications
/internal-curing
/CY)
lb cm)
3. the distribution of the LWA so that it is well-dispersed
Simulations by NIST IC Modeling SW with identical gradations & weights of LWA
LWA as a coarse aggregate LWA as a fine aggregate
distribution of the LWA so that it is dispersed
Simulations by NIST IC Modeling SW with identical gradations & weights of LWA
LWA as a fine aggregate
Internal Curing
Mechanisms ...........Mechanisms ...........
Internal Curing
Mechanisms ...........Mechanisms ...........
Methods used to detect Internal Curing
The Maturity Method detects temperature differences associated
with cement hydration
• ASTM C 1074, Standard Practice for Estimating Concrete Strength by the Maturity Method
Surface resistivity detects changes in pore structure, pore solution
concentration, and pore solution amounts
• AASHTO T358, Standard Method of Test for Surface Resistivity Indication of Concrete’s Ability to Resist Chloride Ion Penetration
Methods used to detect Internal Curing
The Maturity Method detects temperature differences associated
ASTM C 1074, Standard Practice for Estimating Concrete Strength by the
Surface resistivity detects changes in pore structure, pore solution
concentration, and pore solution amounts
AASHTO T358, Standard Method of Test for Surface Resistivity Indication of Concrete’s Ability to Resist Chloride Ion Penetration
Maturity Method...........Maturity Method...........Maturity Method...........Maturity Method...........
T0
= datum temperature
M= Maturity
TTF=Time-Temperature Function
Surface Resistivity
Measurements...........Measurements...........
Surface Resistivity
Measurements...........Measurements...........
• “overall resistivity is dependent • the resistivity of the fluid in the pores,
• the degree of saturation of the concrete,
• the volume and connectivity of the pore
Surface Resistivity
• the volume and connectivity of the pore
• resistivity decreases with a higher water content (i.e., volume) and a more open pore network (i.e., a tortuosity coefficient)”
, R. P., Castro, J., Nantung, T., Paredes, M., & Weiss, J. Variability Analysis of the Bulk
Resistivity Measured Using Concrete Cylinders. Publication FHWA/IN/JTRP-2011/xx. Joint
Transportation Research Program, Indiana Department of Transportation and Purdue University,
West Lafayette, Indiana, 2011, DOI: 10.5703/1288284314646
is dependent on three factors:pores,
degree of saturation of the concrete, and
volume and connectivity of the pore network…
Surface Resistivity
volume and connectivity of the pore network…
with a higher water content (i.e., pore ) and a more open pore network (i.e., a lower
Surface Resistivity and Tortuosity
Schematic representations of electron flow through saturated
concrete mixtures demonstrate why mixtures with higher porosities
tend to have lower electrical resistivities: (a) flow through a
highly porous microstructure; and (b) flow through a dense microstructure
(a) (b)
Surface Resistivity and Tortuosity
“The tortuosity of the pore network
is determined by the microstructure
of the concrete, which develops and
becomes more refined over time due
to cement hydration and secondary
reactions of supplementary reactions of supplementary
cementitious materials (SCMs).
Denser microstructures, resulting
from SCM additions or higher degrees
of hydration, tend to have
more complex and refined pore
networks, giving the concrete a
higher tortuosity and a lower permeability.”
http://www.ltrc.lsu.edu/ltc_13/pdf/presentations/S25_Innovative%20Testing_LTC2013.pdf
Surface Resistivity is like Rapid Chloride Permeability
Surface Resistivity is like Rapid Chloride Permeability
http://www.ltrc.lsu.edu/ltc_13/pdf/presentations/S25_Innovative%20Testing_LTC2013.pdfhttp://www.ltrc.lsu.edu/ltc_13/pdf/presentations/S25_Innovative%20Testing_LTC2013.pdf
Laboratory Testing ........Laboratory Testing ........Laboratory Testing ........Laboratory Testing ........
Experimental Mixture Designs
Materials Weight, lbs. SG(dry)
Cement 540 3.15
Sand 1394 2.63
Lightweight Aggregate 0 1.79
Coarse Aggregate 1 1763 2.55
Water 245 1
Control Mixture Proportions
Water 245 1
Air 0 0
SUM 3942 11.12
Materials Weight, lbs. SG(dry)
Cement 540 3.15
Sand 990 2.63
Lightweight Aggregate 270 1.79
Coarse Aggregate 1 1763 2.55
Water 245 1
Air 0 0
SUM 3808
Lightweight Concrete Mixture Proportions
Experimental Mixture Designs
Unit Weight,
pcf
Volume,
Ft3/yd3ABS%
196.6 2.75
164.1 8.49 0.60%
111.7 0.00 20.00%
159.1 11.08 1.86%
62.4 3.9362.4 3.93
0.0 0.80
27.0
Unit Weight,
pcf
Volume,
Ft3/yd3ABS%
196.6 2.75
164.1 6.03 0.60%
111.7 2.42 20.00%
159.1 11.08 1.86%
62.4 3.93
0.0 0.80
27.0
Experimental
Two mixtures, Control & Lightweight
Conventional mixing techniques
Modified curing protocol:
• Initial curing at 90°F for 3 days• Initial curing at 90°F for 3 days
• Standard moist curing conditions up to 56 days
Standard fresh concrete tests
Hardened concrete tests:
• Compressive strength, surface resistivity, and maturity
Experimental Method
Two mixtures, Control & Lightweight
Standard moist curing conditions up to 56 days
Compressive strength, surface resistivity, and maturity
Test ASTM Control
Mixture
Value
Slump C143 1.6
Results of Tests on Fresh Concrete
Slump C143 1.6
Air Content C231 2.3
Air Temperature C1064 69
Concrete
Temperature
C1064 72
Date of Placement -- 09/14/2015
Time of Placement -- 09:00 AM
Unit Lightweight
Mixture
Value
Unit
inches 2.2 inches
Results of Tests on Fresh Concrete
inches 2.2 inches
% 1.9 %
F 74 F
F 75 F
-- 09/14/2015 --
10:00 AM
Test Name Test Designation
Compressive Strength AASHTO T22
Resistivity AASHTO T358
Hardened Concrete Tests and ASTM Designations
Resistivity AASHTO T358
Maturity ASTM C1074
TemperatureASTM C1074
of Maturity)
Test Designation Units
22Pounds per square Inch,
PSI
358 Kilo-Ohms, KΩ
Hardened Concrete Tests and ASTM Designations
358 Kilo-Ohms, KΩ
1074Degree[C]Days or
Degree[C]-Hours
1074 (Part
Maturity)Degrees[C]
Av
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Co
mp
res
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tre
ng
th,
ps
i
Effects of Light Weight Aggregateon Internal Curing
6,400
7,200
8,000
8,800
Age in Days
Av
era
ge
Co
mp
res
siv
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tre
ng
th,
ps
i
0 10 20
2,400
3,200
4,000
4,800
5,600
Effects of Light Weight Aggregateon Internal Curing
CM
LWA
Age in Days
30 40 50 60
Compressive StrengthControl MixtureLight Weight Aggregate
Av
era
ge
Co
mp
res
siv
e S
tre
ng
th,
ps
i
Effects of Light Weight Aggregate
on Internal Curing
5,600
6,400
7,200
8,000
8,800
Age in Days
Av
era
ge
Co
mp
res
siv
e S
tre
ng
th,
ps
i
1 5
2,400
3,200
4,000
4,800
5,600
Effects of Light Weight Aggregate
on Internal Curing
CM
LWA
Age in Days
10 50 100
Compressive StrengthControl MixtureLight Weight Aggregate
Compressive Strength & vs. Maturity
28
R² = 0.986
R² = 0.9904000
5000
6000
7000
8000
13
714
R² = 0.990
0
1000
2000
3000
4000
0 5000 10000 15000
MaturityControl Strength LWA Strength
Compressive Strength & Surface Resistivityvs. Maturity
56
R² = 0.975
R² = 0.911
15
20
25
0
5
10
20000 25000 30000 35000
MaturityLWA Strength Control SR LWA SR
Equality Plot of Compressive Strength
y = 1.015x + 118.4
R² = 0.997
5000
6000
7000
8000
Str
en
gth
va
lue
s
2000
3000
4000
5000
2000 3000 4000
Str
en
gth
va
lue
s
Avg LWA Compressive Strength values
Equality Plot of Compressive Strength
y = 1.015x + 118.4
R² = 0.997
5000 6000 7000 8000
Avg LWA Compressive Strength values
Equality Plot of Maturity
y = 1.005x + 14.45
R² = 1
20000
25000
30000
35000
R² = 1
0
5000
10000
15000
0 5000 10000 15000
Avg LWA Maturity values
Equality Plot of Maturity
15000 20000 25000 30000 35000
Avg LWA Maturity values
Equality Plot of Surface Resistivity (SR)
7
14
y = 0.571x + 4.409
12
14
16
18
20
Co
ntr
ol
SR
va
lue
1
3
7
0
2
4
6
8
10
12
0 5 10
Avg
Co
ntr
ol
SR
Avg LWA SR values
Equality Plot of Surface Resistivity (SR)
28
56
y = 0.571x + 4.409
R² = 0.930
15 20Avg LWA SR values
Conclusions
For mixture design purposes, accurate absorption values for Fine lightweight aggregates (FLWA) are very important.
FLWA at the quantities required for Internal Curing do not degrade strength as one would expect, relative to a control mixture.
Hydration continues longer when using FLWA than a control mixture.Hydration continues longer when using FLWA than a control mixture.
Surface resistivity indicates that a mixture with FLWA densifies faster than a control mixture.
Questions? ..................................
For mixture design purposes, accurate absorption values for Fine lightweight aggregates (FLWA) are very important.
at the quantities required for Internal Curing do not degrade strength as one would expect, relative to a control mixture.
ydration continues longer when using FLWA than a control mixture.ydration continues longer when using FLWA than a control mixture.
Surface resistivity indicates that a mixture with FLWA densifies faster
Questions? ..................................
Acknowledgements
The support of the Mississippi Department of Transportation is
acknowledged for funding this research project.
All results, data, and conclusions in this presentation are the property
of the Department.of the Department.
The support of the Mississippi Department of Transportation is
acknowledged for funding this research project.
All results, data, and conclusions in this presentation are the property
