CALCİUM SULFOALUMİNATE CEMENT HYDRATİON İN … · CALCİUM SULFOALUMİNATE CEMENT HYDRATİON...
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wt% days Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite wt% days Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite wt% days Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite wt% days SCM Phases Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite wt% days SCM Phases Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite wt% days SCM Phases Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite wt% days SCM Phases Amorphous AFt β-C 2 S Gibbsite Minor initial phases C 4 A 3 S CS H 2 FW Vaterite wt% days SCM Phases Marta García-Maté* , Isabel Santacruz* , Ángeles G. De la Torre, Miguel A.G. Aranda Departamento de Química Inorgánica, Cristalografía y Mineralogía, Facultad de Ciencias, Campus de Teatinos s/n, University of Malaga, 29071 Malaga, Spain *e-mails: [email protected], [email protected] Calcium sulfoaluminate (CSA) cements are receiving increasing attention since their manufacture produces less CO 2 than ordinary Portland cement (OPC) [1]. These binders may have quite variable compositions, but all of them contain Ye’elimite phase, also called Klein’s salt or tetracalcium trialuminate sulfate (C 4 A 3 S ) as the main phase [2]. They may also have minor amount of phases such as C 2 S, CA, C 4 AF, CS , CS H 2 [3], where C=CaO, S=SiO 2 , A=Al 2 O 3 , F=Fe 2 O 3 , S =SO 3 , M=MgO, T=TiO 2 and H=H 2 O. The mortar and concretes derived from these cements show high strength developments at early-ages [4] and could also be used for radioactive element encapsulation [5]. Another environmental strategy for reducing the negative impact of the cement industry is related with the reduction of the clinker content in concretes [6]. This is possible by the partial substitution of cement by supplementary cementitious materials (SCMs) mainly from power stations or metal industry (fly ash, slag or silica fume). The environmental benefits of the use of waste materials are two folds: the clinker reduction will produce lower CO 2 emissions; and the valorization of an “useless” product. Furthermore, fly ash improves some properties of OPC mortars and concretes due to the pozzolanic reaction and its role as a micro-filler. Introducción Objetive Acknowledgements Conclusions References This work has been supported by Spanish Ministry of Science and Innovation through MAT2010-16213 research grant, which is co- funded by FEDER, and Ramón y Cajal Fellowship (RYC-2008-03523). This work deals with the study of the “potential pozzolanic” effect of fly ash (FA) on CSA cement pastes and mortars. This will allow the fabrication of environmentally friendly cements (by the use of CSA clinker and its partial substitution with by-products), and mortars with improved mechanical properties at long ages. CALCİUM SULFOALUMİNATE CEMENT HYDRATİON İN THE PRESENCE OF FLY ASH Hydration time: 3, 7, 28 days 6 months, 1 year CSA Clinker (BELITH S.P.R.L., Belgium) Gypsum 25 wt% Fly Ash (Lada, Spain) 0 wt% 15 wt% 30 wt% Water/binder (w/b) 0.50 0.65 (without FA) Sand Mortar Compressive Strength Cement Pastes Calorimetry TDA-TGA Porosimetry LXRD Rietveld methodology Amorphous quantification (G-factor) Pastes and mortars preparation 10 20 30 40 7d 3d 28d 10 20 30 40 3d 7d 28d 10 20 30 40 3d 7d 28d Hydration studies (pastes) qualitative approach 10 20 30 40 7d 3d 28d [1] Gartner E., Cem. Concr. Res. 2004, 34, 1489. [2] Álvarez-Pinazo G., Cuesta A., García-Maté M., Santacruz I., Losilla E.R., De la Torre A.G., León-Reina L., Aranda M.A.G., Cem. Concr. Res., 2012, 42, 960. [3] Sahu S., Majling J., Cem. Concr. Res., 1993, 23, 1331. [4] Glasser F.P., Zhang L., Cem. Concr. Res., 2001, 31, 1881. [5] Zhou Q., Milestone N.B., Hayes M., J. Hazard. Mater., 2006, 136, 120. [6] Bensted J., Barnes P., Structure and performance of cements. 2002, 2nd ed. New York: Spon Press. AFt Gibbsite C 4 A 3 S CS H 2 Minor initial phases: CT + M + C 2 MS 2 +C 4 AF Minor initial phases: CT + M + C 2 MS 2 +C 4 AF SCM crystalline phases: Mullite + Quartz Minor initial phases: CT + M + C 2 MS 2 +C 4 AF SCM crystalline phases: Mullite + Quartz To be measured 2 θ days 0 wt% FA, w/b=0.65 0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50 Compressive Strength (MPa) Compressive Strength - Mortars 0 wt% FA, w/b=0.65 0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50 0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50 AFt Gibbsite C 4 A 3 S CS H 2 AFt Gibbsite C 4 A 3 S CS H 2 AFt Gibbsite C 4 A 3 S CS H 2 2 θ 2 θ 2 θ PASTE Open Porosit y* (vol %) 0 wt% FA, w/b=0.65 20.3 0 wt% FA, w/b=0.50 14.7 15 wt% FA, w/b=0.50 17.4 30 wt% FA, w/b=0.50 18.8 Porosimetry (pastes) 0 2 4 6 8 10 12 14 0.0 2.0x10 -3 4.0x10 -3 6.0x10 -3 8.0x10 -3 1.0x10 -2 0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50 Normalized Heat Flow (W/g) time (days) 0.0 0.5 1.0 1.5 2.0 0.0 2.0x10 -3 4.0x10 -3 6.0x10 -3 8.0x10 -3 1.0x10 -2 0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50 Normalized Heat Flow (W/g) time (days) 0 2 4 6 8 10 12 14 0 50 100 150 200 250 300 0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50 time (days) Calorimetry (pastes) – 7 days - Pastes (≤ 28 days). By Increasing FA content: Normal heat flow decreases (due to the lower hydraulic active matter) Amorphous/non-diffractive matter content increases. Weight loss decreases (for the same w/b) according to TGA. Open porosity increases. - Mortars (≤ 28 days). By Increasing FA content: Compressive strength values decrease. However, it may be expected a different behaviour at longer hydration times (≥6 months). In any case the decreasing in compressive strengths is small Minor initial phases: CT + M + C 2 MS 2 +C 4 AF 0 wt% FA, w/b=0.65 Amorphous AFt ? -C 2 S Gibbsite Minor Initial phases C 4 A 3 S C S H 2 FW Vaterite days β- 2 S C 4 A S C S 2 days wt% 15 wt% FA, w/b=0.50 DTA-TGA Gibbsite 28 days CO 2 Rietveld AFt 15 wt% FA, w/b=0.50 3 days 28 days Gibbsite Gibbsite C 4 A 3 S Gypsum Gypsum Gypsum Gypsum AFt AF t AFt AFt AFt AFt AFt AFt AFt AFt AFt AFt AFt AFt AFt Vaterite Vaterite Quartz 0 wt% FA, w/b=0.50 28 days Gibbsite CO 2 AFt Hydration studies (pastes) quantitative approach 15 wt% FA, w/b=0.50 Gibbsite Gibbsite C 4 A 3 S Gypsum Gypsum Gypsum Gypsum AFt AFt AFt AF t AFt AFt AFt AFt AFt AFt AFt AFt AFt AFt AFt Vaterite Vaterite Quartz * Mercury Intrusion Porosimetry 2-Theta, deg Counts 20.0 30.0 40.0 X10E 3 0.0 1.0 2.0 3.0 Mullite Mullite Mullite Mullite Mullite Mullite Mullite Mullite Mullite Quartz Quartz Quartz Quartz Hematites Magnesium ferrite Lime Periclase Quartz Gypsum Gypsum Gypsum Gypsum C 4 A 3 S C 4 A 3 S C 4 A 3 S C 4 A 3 S 3d3 0 20 40 60 80 3 7 28
Transcript of CALCİUM SULFOALUMİNATE CEMENT HYDRATİON İN … · CALCİUM SULFOALUMİNATE CEMENT HYDRATİON...
wt%
days
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
wt%
days
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
wt%
days
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
wt%
days
SCM Phases
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
wt%
days
SCM Phases
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
wt%
days
SCM Phases
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
wt%
days
SCM Phases
Amorphous
AFt
β-C2S
Gibbsite
Minor initialphases
C4A3S
CSH2FW
Vaterite
wt%
days
SCM Phases
Marta García-Maté*, Isabel Santacruz*, Ángeles G. De la Torre, Miguel A.G. Aranda
Departamento de Química Inorgánica, Cristalografía y Mineralogía, Facultad de Ciencias, Campus de Teatinos s/n, University of Malaga, 29071 Malaga, Spain
*e-mails: [email protected], [email protected]
Calcium sulfoaluminate (CSA) cements are receiving increasing attention since their manufacture produces less CO2 than ordinary Portland cement (OPC) [1]. These binders may have quite variable compositions, but all of them contain Ye’elimite phase, also called Klein’s salt or tetracalcium trialuminate sulfate (C4A3S) as the main phase [2]. They may also have minor amount of phases such as C2S, CA, C4AF, CS, CSH2 [3], where C=CaO, S=SiO2, A=Al2O3, F=Fe2O3, S=SO3, M=MgO, T=TiO2 and H=H2O. The mortar and concretes derived from these cements show high strength developments at early-ages [4] and could also be used for radioactive element encapsulation [5]. Another environmental strategy for reducing the negative impact of the cement industry is related with the reduction of the clinker content in concretes [6]. This is possible by the partial substitution of cement by supplementary cementitious materials (SCMs) mainly from power stations or metal industry (fly ash, slag or silica fume). The environmental benefits of the use of waste materials are two folds: the clinker reduction will produce lower CO2 emissions; and the valorization of an “useless” product. Furthermore, fly ash improves some properties of OPC mortars and concretes due to the pozzolanic reaction and its role as a micro-filler.
Introducción
Objetive
Acknowledgements
Conclusions References
This work has been supported by Spanish Ministry of Science and Innovation through MAT2010-16213 research grant, which is co-funded by FEDER, and Ramón y Cajal Fellowship (RYC-2008-03523).
This work deals with the study of the “potential pozzolanic” effect of fly ash (FA) on CSA cement pastes and mortars. This will allow the fabrication of environmentally friendly cements (by the use of CSA clinker and its partial substitution with by-products), and mortars with improved mechanical properties at long ages.
CALCİUM SULFOALUMİNATE CEMENT HYDRATİON İN THE PRESENCE OF FLY ASH
Hydration time: 3, 7, 28 days
6 months, 1 year
CSA Clinker (BELITH S.P.R.L., Belgium)
Gypsum 25 wt%
Fly Ash (Lada, Spain)
0 wt% 15 wt% 30 wt%
Water/binder (w/b)
0.50 0.65 (without FA)
Sand
Mortar
Compressive Strength
Cement Pastes
Calorimetry TDA-TGA Porosimetry
LXRD Rietveld methodology Amorphous quantification (G-factor)
Pastes and mortars preparation
10 20 30 40
7d
3d
28d
10 20 30 40
3d
7d
28d
10 20 30 40
3d
7d
28d
Hydration studies (pastes) qualitative approach
10 20 30 40
7d
3d
28d
[1] Gartner E., Cem. Concr. Res. 2004, 34, 1489. [2] Álvarez-Pinazo G., Cuesta A., García-Maté M., Santacruz I., Losilla E.R., De la Torre A.G., León-Reina L., Aranda M.A.G., Cem. Concr. Res., 2012, 42, 960. [3] Sahu S., Majling J., Cem. Concr. Res., 1993, 23, 1331. [4] Glasser F.P., Zhang L., Cem. Concr. Res., 2001, 31, 1881. [5] Zhou Q., Milestone N.B., Hayes M., J. Hazard. Mater., 2006, 136, 120. [6] Bensted J., Barnes P., Structure and performance of cements. 2002, 2nd ed. New York: Spon Press.
AFt Gibbsite C4A3S CSH2
Minor initial phases: CT + M + C2MS2 +C4AF
Minor initial phases: CT + M + C2MS2 +C4AF SCM crystalline phases: Mullite + Quartz
Minor initial phases: CT + M + C2MS2 +C4AF SCM crystalline phases: Mullite + Quartz
To be measured
2 θ days
0 wt% FA, w/b=0.65 0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50
Com
pres
sive
Str
engt
h (M
Pa)
Compressive Strength - Mortars
0 wt% FA, w/b=0.65
0 wt% FA, w/b=0.50
15 wt% FA, w/b=0.50
30 wt% FA, w/b=0.50
0 wt% FA, w/b=0.50
15 wt% FA, w/b=0.50
30 wt% FA, w/b=0.50
AFt Gibbsite C4A3S CSH2
AFt Gibbsite C4A3S CSH2
AFt Gibbsite C4A3S CSH2
2 θ
2 θ
2 θ
PASTE
Open Porosit
y* (vol %)
0 wt% FA, w/b=0.65 20.3
0 wt% FA, w/b=0.50 14.7
15 wt% FA, w/b=0.50 17.4
30 wt% FA, w/b=0.50 18.8
Porosimetry (pastes)
0 2 4 6 8 10 12 140.0
2.0x10-3
4.0x10-3
6.0x10-3
8.0x10-3
1.0x10-2
0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50
Nor
mal
ized
Hea
t Flo
w (W
/g)
time (days)
0.0 0.5 1.0 1.5 2.00.0
2.0x10-3
4.0x10-3
6.0x10-3
8.0x10-3
1.0x10-2
0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50
Nor
mal
ized
Hea
t Flo
w (W
/g)
time (days)
0 2 4 6 8 10 12 140
50
100
150
200
250
300
0 wt% FA, w/b=0.50 15 wt% FA, w/b=0.50 30 wt% FA, w/b=0.50
time (days)
Calorimetry (pastes) – 7 days
- Pastes (≤ 28 days). By Increasing FA content: Normal heat flow decreases (due to the lower hydraulic active matter) Amorphous/non-diffractive matter content increases. Weight loss decreases (for the same w/b) according to TGA. Open porosity increases. - Mortars (≤ 28 days). By Increasing FA content: Compressive strength values decrease. However, it may be expected a different behaviour at longer hydration times (≥6 months). In any case the decreasing in compressive strengths is small
Minor initial phases: CT + M + C2MS2 +C4AF
0 wt% FA, w/b=0.65
Amorphous
AFt
? - C 2 S
Gibbsite
Minor Initial phases
C 4 A 3 S
C S H 2 FW
Vaterite
days
β - 2 S
C 4 A S
C S 2
days
wt%
15 wt% FA, w/b=0.50
DTA-TGA
Gibbsite
28 days
CO2
Rietveld
AFt
15 wt% FA, w/b=0.50 3 days
28 days
Gibb
site
Gibb
site
C 4A 3
S
Gyps
um
Gyps
um
Gyps
um
Gyps
um
AFt
AF t AF
t
AFt
AFt
AFt AF
t AF
t
AFt
AFt
AFt
AFt AF
t AFt
AFt
Vate
rite
Vate
rite
Qua
rtz
0 wt% FA, w/b=0.50 28 days
Gibbsite CO2
AFt
Hydration studies (pastes) quantitative approach
15 wt% FA, w/b=0.50
Gibb
site
Gibb
site
C 4A 3
S
Gyps
um
Gyps
um
Gyps
um
Gyps
um
AFt
AFt
AFt
AF t AF
t
AFt
AFt
AFt
AFt
AFt
AFt
AFt A
Ft
AFt
AFt
Vate
rite
Vate
rite
Qua
rtz
* Mercury Intrusion Porosimetry
2-Theta, deg
Cou
nts
20.0 30.0 40.0
X10E
3
0.0
1.0
2.0
3.0
Mul
lite
Mul
lite
Mul
lite
Mul
lite
Mul
lite
Mul
lite
Mul
lite Mul
lite
Mul
lite
Qua
rtz
Qua
rtz
Qua
rtz
Qua
rtz
Hem
atite
s M
agne
sium
ferr
ite
Lim
e
Peric
lase
Qua
rtz
Gyps
um
Gyps
um
Gyps
um Gy
psum
C 4A 3
S
C 4A 3
S
C 4A 3
S
C 4A 3
S
3d3 0
20
40
60
80
1 2 33 7 28
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