ENVIRONMENTAL GEOMECHANICS CE-641 Lecture No. 11-12 Prof. D N - - PowerPoint PPT Presentation

ENVIRONMENTAL GEOMECHANICS

CE-641 Lecture No. 11-12

• Prof. D N Singh

Department of Civil Engineering

Sub-topics

• Need for Geomaterial characterization
• Geotechnical
• Mineralogy
• Morphology
• Physical
• Chemical

Pore-solution sampling Corrosion potential Sorption-Desorption

• Thermal
• Electrical
• Magnetic
• Biological
• Radiation

09.09.2019 Lecture No. 11-12 Lecture Name: 11.09.2019 Geomaterial Characterization

Physical Chemical Mineralogical Thermal Electrical Alterations in Geotechnical Properties??

Thermo-hydro-mechanical-Chemical (THMC) models in Geotechnical Engg. (Atomic waste disposal & Design of Buffers) Thermo-hydro-mechanical-Chemical-Biological (THMCB) models (More realistic) Need for Geomaterial Characterization

GEOTECHNICAL CHARACTERIZATION

• Void Ratio & Porosity
• Compaction
• Consolidation and Compressibility
• Hydraulic conductivity
• Shear Strength Parameters
• Collapse Potential (CP)

= [(e0-ef)/(1+e0)] in %

GEOTECHNICAL CHARACTERIZATION

• Void Ratio & Porosity
• Compaction
• Consolidation and Compressibility
• Shear Strength Parameters
• Hydraulic conductivity
• Collapse Potential (CP)

= [(e0-ef)/(1+e0)] in %

’ ef e0

Inundation

MINERALOGICAL CHARACTERIZATION

• X-Ray Diffraction (XRD)
• Scanning Electron Microscope (SEM)

Mineralogical Characterization

XRD Diffractograms

200 400 600 M M M M M M M Q Q M M M M M Q

C-I

100 200 300 400 500 G= Glassy phase M=Mullite Q= Quartz M M M M M M M M M M M M M M

Cu-K (2 Deg.) Relative Intensity

C-II

10 20 30 40 50 60 70 80 90 100

50 100 150 G

GGBFS

Minerals Present in Materials Material Mineral* CS Anorthite, Quartz, Montmorillonite WC Kaolinite, Illite IC Calcite, Clinoptilolite, Opal CT, Illite, Smectite, Palygorskite RSS Quartz, Feldspar, Hematite BSS Quartz, Feldspar FA-I Quartz, Mullite, Hematite FA-II Quartz, Mullite, Hematite C-I Quartz, Mullite C-II Mullite GGBFS Glassy phase * JCPDS 1994

Powder diffraction file, 44, 7354-CD ROM (PDF 1- 44), Int. Centre for Diffraction Data, Pennsylvania, USA. 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

(a) Sample S1F1 (b) Sample S2F2 (c) Sample SA35F2 (d) Sample SA50F3 (e) Sample SA35F4 (f) Sample SA50F5

SEM Micrographs (Original ash samples)

(a) Sample CA8S12F1 (b) Sample CA8S12F2 (c) Sample CA8S12F3 (d) Sample CA8S12F4 (e) Sample CA8S12F5 (f) Sample CA8S12F6

Agglomeration of Ash Particles due to Flue Gas Conditioning

SF BFS

SEM micrographs of Silica Fumes & Ground Granulated Blast Furnace Slag (GGBFS/BFS)

Morphological characterization

Confocal micrographs (2-Dimensional) SS1 SS3 CS3 Optical micrographs (3 D) SS1 Glass beads SS2 & SS3

cir min in max  

 r r S

in max 1 i i  



 r N r R

N

Sphericity, S, =(R+S)/2 Roundness, R, Regularity, ,

rmin-cir rmax-in ri ri

Sample S R 

SS1 0.82 0.61 0.715 SS2 0.76 0.60 0.675 SS3 0.75 0.49 0.625 CS1 0.89 1.0 0.94 CS2 0.92 1.0 0.96 CS3 0.90 1.0 0.95

Image Analysis System (Historic: Laser Particle Scanner) Contemporary

Granulometry (Morphology)

A few Gadgets….

3-D Sieves (Ultra-sieves) 125 mm - 20 µm

EyeWizard 3D surface laser topography and 3D-DFD gyration scanning with use of a 5 axis system

Laser Obscuration Time Method (LOTM)

3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 200 400 600 800 1000 1200 1400

FA 1 FA 2

Particle size ( m)

200 400 600 800 1000 1200 1400 1600

FA 3 BFS

Number of particles

500 1000 1500 2000 2500 3000 3500 4000 4500 5000

SF

Soft Imaging (Laser Particle Scanning)

Property FA 1 FA 2 FA 3 GGBFS SF G 2.03 2.3 2.38 2.84 2.1 Specific surface area (cm2/g) 2988 3602 5048 4073 200000 Sand size (>4.75 mm) % ** Silt size (0.002-0.075 mm) % 100 95 90 97 ** Clay size (<0.002 mm) % 5 10 3 ** ** Not applicable

Particle size Range (m) Number of particles Percentage of particles FA-1 FA-2 FA-3 GGBFS SF FA-1 FA-2 FA-3 GGBFS SF 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 0.3 0.0 21.0-24.0 2 5 3 0.1 0.3 0.1 24.0-27.0 1 1 2 3 0.1 0.1 0.1 27.0-30.0 2 1 1 5 2 0.1 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 0.1 0.2 36.0-39.0 1 0.1

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 (SB)

Ss is the SSA of cement (= 0.346 m2/g) e is the void ratio of the sample es is the void ratio of cement (= 0.5) Ts is the time of manometer drop for cement (= 77.18 s) T is the time of manometer drop for the sample

e) (1 T e T e ) e (1 S S

s 3 s 3 s S B

  

Thermo Gravimetric Analysis

TGA and DTA curve for OLA and ALA6 samples (Inert atmosphere) (Dry air atmosphere)

600 200 400 800

DTA TGA

• Temp. difference ( T)

Endo. Exo. OLA ALA6

Weight loss (%)

20 40 60 80 20 40 60 80 100 100

100 200 300 400 500 600

• 5.0
• 4.8
• 4.6
• 4.4
• 4.2
• 4.0
• 3.8
• 3.6
• 3.4
• 3.2
• 3.0

Heat flow (mW)

FA-3

Temperature (

0C)

DSC

200 400 600 800 100 80 60 40 20 Temperature difference(,

0C)

Temperature (

0C)

Weight loss (%) FA-3 DTA TGA

Endo. Exo.

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

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 4.58 0.27 38.9 001 0.01 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

XRF Studies

Calibration of XRF- Setup

• Physical Calibartion
• Chemical Calibration

Inductively Coupled Plasma (ICP) Atomic Absorption Spectrophotometer (AAS)

Historic Contemporary Gas Chromatograph with high resolution Mass Spectrometer (GC-HRMS)

Fourier Transform Infra-Red (FTIR) Spectroscopy Nuclear Magnetic Resonance Spectrometer

pH determination

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 Water Quality Analyzer

Material CEC(meq./100g) CS 18.6 WC 5.0 IC 12.6 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

Cation-exchange Capacity

            



(g) sample

• f

wt. 1000 cation the

• f

weight Equivalent (ml) extract

• f

Vol. 100 g/ml) ( Ca

• f

ion Concentrat CEC

2



IS:2720

Micro-biological Characterization (Bio-geo interface)

Soil is not a lifeless entity…!