ENVIRONMENTAL GEOMECHANICS CE-641 Lecture No. 11-12 Prof. D N Singh Department of Civil Engineering
09.09.2019 Lecture No. 11-12 Lecture Name: 11.09.2019 Geomaterial Characterization Sub-topics • Need for Geomaterial characterization • Geotechnical • Mineralogy • Morphology • Physical • Chemical Pore-solution sampling Corrosion potential Sorption-Desorption • Thermal • Electrical • Magnetic • Biological • Radiation
Need for Geomaterial Characterization Physical Chemical Alterations in Mineralogical Geotechnical Thermal Properties?? Electrical Thermo-hydro-mechanical-Chemical (THMC) models in Geotechnical Engg. (Atomic waste disposal & Design of Buffers) Thermo-hydro-mechanical-Chemical-Biological (THMCB) models (More realistic)
GEOTECHNICAL CHARACTERIZATION • Void Ratio & Porosity • Compaction • Consolidation and Compressibility • Hydraulic conductivity • Shear Strength Parameters • Collapse Potential (CP) = [(e 0 -e f )/(1+e 0 )] in %
GEOTECHNICAL CHARACTERIZATION • Void Ratio & Porosity • Compaction • Consolidation and Compressibility • Shear Strength Parameters Inundation • Hydraulic conductivity e 0 • Collapse Potential (CP) = [(e 0 -e f )/(1+e 0 )] in % e f ’
MINERALOGICAL CHARACTERIZATION • X-Ray Diffraction (XRD) • Scanning Electron Microscope (SEM)
Mineralogical Characterization Minerals Present in Materials G= Glassy phase M=Mullite Q= Quartz 600 M Mineral * Material C-I Q CS Anorthite, Quartz, 400 M M M Montmorillonite M Q M Q 200 WC Kaolinite, Illite M M M M M Calcite, Clinoptilolite, Opal CT, IC 0 Illite, Smectite, Palygorskite 500 C-II M 400 RSS Quartz, Feldspar, Hematite Relative Intensity 300 M BSS Quartz, Feldspar M M M M M 200 M FA-I Quartz, Mullite, Hematite M M M M M M M 100 FA-II Quartz, Mullite, Hematite 150 G C-I Quartz, Mullite GGBFS C-II Mullite 100 GGBFS Glassy phase 50 * JCPDS 1994 Powder diffraction file, 44, 7354-CD ROM 0 (PDF 1- 44), Int. Centre for Diffraction 10 20 30 40 50 60 70 80 90 100 Cu-K (2 Deg.) Data , Pennsylvania, USA. XRD Diffractograms ICSD Inorganic Crystal Structure Databasedatabase
Minerals the Original and Activated ash samples (treated with NaOH) Minerals Original Activated Quartz Mullite NaP1 zeolite X Hydroxy-sodalite X zeolite
SEM Micrographs (Original ash samples)
SEM Photographs of Activated ash samples
SEM Micrographs (Original ash samples) (a) Sample S1F1 (b) Sample S2F2 (c) Sample SA35F2 (d) Sample SA50F3 (e) Sample SA35F4 (f) Sample SA50F5
Agglomeration of Ash Particles due to Flue Gas Conditioning (a) Sample CA8S12F1 (b) Sample CA8S12F2 (c) Sample CA8S12F3 (d) Sample CA8S12F4 (e) Sample CA8S12F5 (f) Sample CA8S12F6
SEM micrographs of Silica Fumes & Ground Granulated Blast Furnace Slag (GGBFS/BFS) SF BFS
Morphological characterization Confocal micrographs (2-Dimensional) SS1 SS3 CS3 Optical micrographs (3 D) SS1 Glass beads SS2 & SS3
r max in r min-cir S Sphericity, S , r min cir r i N r i i 1 N Roundness, R , R r max in r i r max-in =( R + S )/2 Regularity, , R Sample S 0.715 SS1 0.82 0.61 0.675 SS2 0.76 0.60 0.625 SS3 0.75 0.49 CS1 1.0 0.94 0.89 1.0 0.96 CS2 0.92 1.0 0.95 CS3 0.90
Granulometry (Morphology) Image Analysis System (Historic: Laser Particle Scanner) Contemporary
A few Gadgets…. EyeWizard 3-D Sieves (Ultra-sieves) 3D surface laser topography and 3D-DFD gyration 125 mm - 20 µm scanning with use of a 5 axis system Laser Obscuration Time Method (LOTM)
Soft Imaging (Laser Particle Scanning) 5000 4500 4000 SF 3500 3000 2500 2000 1500 Number of particles 1000 500 0 1600 1400 FA 3 1200 1000 BFS 800 600 400 200 0 1400 1200 FA 1 1000 FA 2 800 600 400 200 0 0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 Particle size ( m)
Property FA 1 FA 2 FA 3 GGBFS SF G 2.03 2.3 2.38 2.84 2.1 Specific surface area 2988 3602 5048 4073 200000 (cm 2 /g) Sand size (>4.75 mm) % 0 0 0 0 ** Silt size (0.002-0.075 mm) % 100 95 90 97 ** Clay size (<0.002 mm) % 0 5 10 3 ** ** Not applicable Number of particles Percentage of particles Particle size FA-1 FA-2 FA-3 GGBFS SF FA-1 FA-2 FA-3 GGBFS SF Range ( m) 0.0-3.0 944 1295 1410 789 4451 47.6 53.0 53.1 40.3 90.6 3.0-6.0 709 989 1061 816 343 35.8 40.5 39.9 41.7 7.0 6.0-9.0 228 116 148 247 48 11.5 4.8 5.6 12.6 1.0 9.0-12.0 57 17 21 59 33 2.9 0.7 0.8 3.0 0.7 12.0-15.0 24 11 4 16 17 1.2 0.5 0.2 0.8 0.3 15.0-18.0 6 2 2 9 6 0.3 0.1 0.1 0.5 0.1 18.0-21.0 4 1 1 5 2 0.2 0 0 0.3 0.0 21.0-24.0 2 0 0 5 3 0.1 0 0 0.3 0.1 24.0-27.0 1 1 0 2 3 0.1 0 0 0.1 0.1 27.0-30.0 2 1 1 5 2 0.1 0 0 0.3 0.0 30.0-33.0 2 6 3 3 4 0.1 0.2 0.1 0.2 0.1 33.0-36.0 2 1 2 3 2 0.1 0 0.1 0.2 0 36.0-39.0 1 0 0 0 0 0.1 0 0 0 0
Specific Surface Area (SSA) Determination BET nitrogen adsorption Absorption of Ethylene Glycol Monoethyle Ether (EGME) method Methylene blue (MB) dye method Mercury Intrusion Porosimetry (MIP) He gas pycnometer Blaine’s apparatus
MIP He gas pycnometer
Blaine’s Air Permeability Apparatus (ASTM C 204) Portland cement as a standard reference material Specific-surface area (S B ) 3 S (1 e ) e T S s S B 3 e T (1 e) s s S s is the SSA of cement (= 0.346 m 2 /g) e is the void ratio of the sample e s is the void ratio of cement (= 0.5) T s is the time of manometer drop for cement (= 77.18 s) T is the time of manometer drop for the sample
Thermo Gravimetric Analysis
0 TGA Exo. 20 Weight loss (%) Temp. difference ( T) (Dry air atmosphere) 40 DTA 60 Endo. 80 OLA ALA6 TGA and DTA curve 100 for OLA and ALA6 0 samples 20 40 60 (Inert atmosphere) 80 100 800 400 600 200
0 -3.0 FA-3 0 C) -3.2 DSC TGA Temperature difference( , FA-3 20 -3.4 Weight loss (%) -3.6 Heat flow (mW) 40 -3.8 Exo. -4.0 60 -4.2 DTA -4.4 Endo. 80 -4.6 -4.8 100 -5.0 0 200 400 600 800 0 100 200 300 400 500 600 0 C) Temperature ( 0 C) Temperature (
CHEMICAL CHARACTERIZATION X-Ray Fluorescence (XRF) Inductively Coupled Plasma (ICP/ICP-MS) pH value Gas Chromatography (GC-MS) Nuclear Magnetic Resonance (NMR) Fourier Transform Infra-Red (FTIR) Spectroscopy Cation Exchange Capacity (CEC) Pore-solution analysis
XRF Pallets
Calibration of XRF Studies XRF- Setup Physical Calibartion Chemical Calibration Elemental Composition (% by weight) of Materials Material Element CS WC IC RSS BSS FA-I FA-II C-I C-II GGBFS Si 15.78 20.32 11.52 39.21 40.71 25.53 28.30 24.65 23.62 15.56 Al 5.75 17.77 1.67 2.65 3.29 15.95 15.92 20.70 21.92 8.59 Fe 8.23 1.09 1.19 0.50 0.94 2.51 2.31 1.38 1.81 0.25 Ti 1.53 2.88 0.03 0.22 0.14 2.12 1.45 1.15 1.02 0.37 S - - 0.1 - - 0.01 0.23 0.11 0.03 0.39 Ca 38.9 001 0.01 4.58 0.27 3.20 0.11 0.06 0.10 26.50 K 0.54 0.06 0.13 2.42 1.49 0.77 0.55 1.07 1.14 0.19 Mg 0.99 0.45 0.48 0.09 0.19 0.33 0.24 0.41 0.24 5.52 P 0.07 0.02 5.0 0.01 0.02 0.18 0.25 0.12 0.06 0.02 Sr 0.02 0.00 0.14 - - 0.06 0.07 0.08 0.05 0.08 Ba - - - - - 0.66 0.07 0.11 0.12 0.06 Na 1.49 0.13 - 0.04 - 0.09 0.04 0.08 0.02 0.05 Mn 0.12 0.04 0.01 - 0.04 0.03 0.01 0.01 0.01 0.01 Si +Al+Fe 29.76 39.18 14.39 42.35 44.94 43.98 46.54 46.74 47.35 24.41
Inductively Coupled Plasma (ICP) Atomic Absorption Spectrophotometer (AAS) Historic Gas Chromatograph with high resolution Mass Spectrometer (GC-HRMS) Contemporary
Fourier Transform Infra-Red (FTIR) Nuclear Magnetic Resonance Spectroscopy Spectrometer
pH determination Water Quality Analyzer Glass calomel electrode is used Soil solutions with different Liquid to solid ratios pH Temperature Total Dissolved Solids Electrical Conductivity Chemical Oxygen demand Biological Oxygen Demand
Cation-exchange Capacity Material CEC(meq./100g) 2 Concentrat ion of Ca ( g/ml) 100 Vol. of extract (ml) CEC CS 18.6 Equivalent weight of the cation 1000 wt. of sample (g) WC 5.0 IC 12.6 IS:2720 RSS 3.5 BSS 3.4 FA-I 4.5 FA-II 5.2 C-I 3.9 C-II 4.1 GGBFS Not applicable
Micro-biological Characterization (Bio-geo interface)
Soil is not a lifeless entity…!
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