Geomaterial Characterization Sub-topics Need for Geomaterial - - PowerPoint PPT Presentation

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Geomaterial Characterization Sub-topics Need for Geomaterial - - PowerPoint PPT Presentation

Oct 27, 2022 427 likes •777 views

Geomaterial Characterization Sub-topics Need for Geomaterial characterization Geotechnical Micro-biological (Bio-geo Interface) Mineralogy Morphology Physical Chemical Pore-solution sampling Corrosion potential

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SLIDE 1

Geomaterial Characterization Sub-topics

  • Need for Geomaterial characterization
  • Geotechnical
  • Micro-biological (Bio-geo Interface)
  • Mineralogy
  • Morphology
  • Physical
  • Chemical

Pore-solution sampling Corrosion potential Sorption-Desorption

  • Thermal
  • Electrical
  • Magnetic
  • Radiological
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SLIDE 2

MINERALOGICAL CHARACTERIZATION

  • X-Ray Diffraction (XRD)
  • Scanning Electron Microscope (SEM)
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SLIDE 3

SF BFS

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

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SLIDE 4

Compacted sample Cubic specimen

Determination of fabric structure of fine-grained soils Using SEM

Specimen preparation (Challenges):

  • Removal of pore fluid from the specimen without disturbing its microstructure.
  • Freeze-drying technique (for swelling/shrinking type of soils)
  • Air-drying technique (for non swelling/shrinking type of soils)
  • Specimen should be able to withstand the vacuum inside the microscope.
  • As illumination is with electrons, specimen should be made to conduct electricity.
  • Specimen are coated with a very thin layer of Gold or Carbon (a sputter coater).
  • Gold coating film can absorb X-ray signal generated into the specimen.
  • For obtaining X-ray spectrum of a non-conducting sample a coating material very

transparent to the X-ray (Carbon) must be utilized.

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SLIDE 5
  • Geomaterials are composed of wide range of particle sizes and

shapes and are porous in nature.

  • A knowledge of pore structure of these materials is important as it can

give insight in to both the microstructure and the performance.

  • Rather than measuring the porosity, It becomes more informative if the

manner in which volume is distributed With respect to pore size.

Mercury Intrusion Porosimetry (MIP) Dead end Closed Inter-connected Passing

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SLIDE 6
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SLIDE 7

Morphological characterization

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

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SLIDE 8

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

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SLIDE 9

PHYSICAL CHARACTERIZATION Image Analysis System

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SLIDE 10

1E-3 0.01 0.1 1 10 20 40 60 80 100

OLA

1E-3 0.01 0.1 1 10 20 40 60 80 100

ALA6

% finer Particle size (mm)

Gradational analysis Ultra-sieves

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SLIDE 11

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)

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SLIDE 12

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

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SLIDE 13

Specific Surface Area 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

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SLIDE 14

MIP He gas pycnometer

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SLIDE 15

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

  

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SLIDE 16

Thermo Gravimetric Analysis

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SLIDE 17

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

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SLIDE 18

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.

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SLIDE 19

CHEMICAL CHARACTERIZATION

  • X-Ray Fluorescence (XRF)
  • Inductively Coupled Plasma (ICP)
  • pH value
  • Cation Exchange Capacity (CEC)
  • Pore solution analysis
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SLIDE 20

XRF Pallets

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SLIDE 21

Inductively Coupled Plasma Unit AAS

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SLIDE 22

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
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SLIDE 23

5 10 15 20 25 30 7.0 7.2 7.4 7.6 7.8 8.0

L/S

5 10 20 30 40

pH

Time (days)

variation of pH of the sample

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SLIDE 24

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

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SLIDE 25

Micro-biological Characterization (Bio-geo interface)

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SLIDE 26
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SLIDE 27
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SLIDE 28

IIT Bombay Environmental Geomechanics Lecture No. 5 D N Singh 28

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SLIDE 29

IIT Bombay Environmental Geomechanics Lecture No. 5 D N Singh 29

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SLIDE 30

IIT Bombay Environmental Geomechanics Lecture No. 5 D N Singh 30

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SLIDE 31

IIT Bombay Environmental Geomechanics Lecture No. 5 D N Singh 31

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SLIDE 32

IIT Bombay Environmental Geomechanics Lecture No. 5 D N Singh 32

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SLIDE 33

IIT Bombay Environmental Geomechanics Lecture No. 5 D N Singh 33

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SLIDE 34

IIT Bombay Environmental Geomechanics Lecture No. 5 D N Singh 34