Tatiana Pyatina and Toshifumi Sugama Brookhaven National Laboratory Work performed under DOE EERE Geothermal Technologies Program Objectives and approach Strength recovery Fractures and cracks ID: 1021518
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1. High-Temperature Self-Healing Geothermal Cement CompositesTatiana Pyatina and Toshifumi SugamaBrookhaven National Laboratory Work performed under DOE EERE Geothermal Technologies Program
2. Objectives and approachStrength recoveryFractures and cracks sealingHigh temperatures and aggressive environments (at up to 300oC): self-healing requirementsApproach and test methodsOptical microscope for sealing, analytical technics for phase identificationControlled damageCompressive and bond strengthsbefore and after the damageBonding recoveryBadGood
3. Self-healing cementitious materials3
4. Matrix strength recovery (5 days of healing): A+>100%; A 80-99%; B 60-79%; C<60% (10% CMF in all formulations)Cement systemCuring Environment (270oC and 350oC)WaterAlkali CarbonateHypersaline brineThermal shock (350oC-25oC)Class G/SiO2CBBACAC (#80)/FAF*AAAA+CAC(#80)/Zeolite 1AAA+A+Class G/SiO2/Zeolite 1CACN/AOPC/Zeolite 2/SiO2**A+ACA+CAP/FAFCCAA+GBFS/FACBBBAGBFS/FAC/Zeolite 1AAAAFAC/FAFCBCA* - Thermal Shock Resistant Cement (TSRC)** - FlexCem
5. Lap shear bond testing Visual observation to identify the bond failure modes and CS’s corrosions for samples after exposure in water: Cohesive and mixed failures (left) and adhesive failure (right). Lap shear bond strength (left) and tensile bond extension (right) for six cements adhering to CS after exposure for 1 day to 300°C water or alkali carbonate environments.
6. Self-adhering behavior of TSRC with micro-glass fiber (MGF) at 300oC.water CO2brine
7. Self-adhering behaviors of very high strength Slag/SiO2 cement with MGF at 300oCwater CO2brine
8. Cement systemCuring Environment (300oC)WaterAlkali CarbonateHypersaline brineFormulations with Micro Glass Fibers (MGF)Class G/SiO2/MGFAAACAC (#80)/FAF/MGFA+A+A+CAC(Fondu)/FAF/MGFA+A+A+CaP/FAF**CBAFAC/FAF/MGFCCBGBFS/SiO2/MGFAA+BLap Shear Bond strength/Bond extension, psi/%Class G/SiO2/MGF52/1.4330/1.374/1.75CAC (#80)/FAF/MGF237/2.81347/4.47260/3.51CAC(Fondu)/FAF/MGF*4/1.2235/1.446/0.98CaP/FAF196/2.37125/1.49106/1.5FAC/FAF/MGF189/2.17228/2.6415/1.28GBFS/SiO2/MGF345/4.22254/3.3398/1.35Universal healing aid – micro glass fibers (MGF)Matrix strength recovery: A+>100%; A 80-99%; B 60-79%; C<60%*- slow-set system; ** - brittle cement
9. Brittle cement in thermal shock tests - after heating to 350oCGBFS/SiO2/MGFBefore testAfter heating to 350oC
10. Developed hair cracksTough cement in thermal shock tests - 6 cycles of heating to 350oC – 25oC water coolingThermal shock resistant cement (CAC(#80)/FAF/SMS) with GMFBefore testAfter test
11. Effect of retarder on strength recovery and cracks sealing – 1% Tartaric AcidNo TA TA TANo TAWaterCarbonateWaterCarbonateBefore healingAfter healingBefore healingAfter healingSiCaSiCa
12. Phases participating in self-healingCrystalline phases:Matrix strength recovery – Calcium aluminum silicates (feldspars); sodium aluminum silicates (zeolites); calcium silicate (TA); carbonated calcium-aluminum-silicate (in carbonate environment); magnesium (calcium) silicates (in brine)Cracks – Zeolites; calcium-aluminum silicates (feldspar and Ca-containing mica type)Amorphous phases: Sodium(calcium)-aluminum-silicate hydrateEffect of GMF: Increased crystallinity at short curing times; Mg-containing silicates in all environments – improved strength recovery (fast MGF reaction)Water
13. Summary:Cementitious materials can be formulated to have self-healing properties allowing strength recovery and cracks sealing at temperatures up to 300oC (inorganic matrix)CAC/FAF/SMS blend (TSRC) showed the best performance among tested materials Strength recovery and cracks sealing maybe further improved with additives such as Micro Glass Fibers and set retarder (TA)MGF are most appropriate for formulations with high amorphous phase content Future directions:Self healing behavior after long-term exposure tests (steam, alkali carbonate and geothermal brine)Phase identification of healing reaction productsHealing behavior after long term exposures to sc CO2/brine and pH 1 H2SO4/brine of cement matrix and cement-casing bonding
14. water CO2brineBefore healingAfter healing 1865 psi1865 psi2150 psiThermal shockResistance and Bond StrengthCrystalline phases:Zeolites – SodaliteCancriniteAnalcime ThomsoniteCAC/FAF/SMSOPC/SiO2CarbonationresistanceStable Crystalline phase:Carbonated sodaliteSodium Cancrinite H0.88Na8Al6(SiO4)6(CO3)1.44(H2O)2Before CO2After CO2Acid resistanceStable Crystalline phase:AluniteAmorphous phase:Aluminum silicateOPC/SiO2CAC/FAF/SMSSealingBeforeAfterStrength recovery and fractures sealing1780 psi2504 psi1510 psi2925 psiCAC/FAF/SMSLap Shear Bond StrengthCements formulationsOPC/SiO2CAPCAC/FAF/SMS
15. Questions?