Sand Properties understanding common tests

School of Civil and Environmental EngineeringParticulate Media Research Laboratory

Douglas Cortes Carlos Santamarina

Georgia Construction Aggregate Association – Workshop 2008

Particle size

Particle shape / crushing

emin emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

Particle size

Particle shape / crushing

emin emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

Sieve Analysis

Computing Particle Size Distribution

0

20

40

60

80

100

0.010.1110Sieve opening [mm]

Perc

ent p

assi

ng [

%]

D10

10%

0

20

40

60

80

100

0.010.1110Sieve opening [mm]

Perc

ent p

assi

ng [

%]

Gap GradedWell GradedPoorly Graded

10

60

DDCu =

6010

230 )(DD

DCc⋅

=

Uniformity coefficient

Coefficient of curvature

Important Particle Size Parameters

D/d=2

D/d=10

volume fraction of small particles

poro

sity

, n

0 20 40 60 80 100%

0.36

0.32

0.28

0.24

Guyon et al. (1987)

Size Distribution Packing Density

BBC News In pictures Visions of Science

Caution: Capillarity

Capillarity Holds!

www.phys.virginia.edu

Caution: Electrical Forces

Particle size

Particle shape / crushing

emin emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

mm

Ottawa sand kaolinite

crushed granite marl

sintered lead precipitated carbonate foraminiferan

table salt

lentil

rice

μm mm

diatom

diatom

(The Diatoms –1990)

μm

Why Shape? Formation History

# 89 material

# 5 material

# 6 material

# 7 material

# 4 material

blasting crusher screen

base material

crusher screen

crusher

screen

sand pool

< # 200 – pond screening

washed sand

M10

Gyratory Jaw Cone

GDOT Aggregate

High Fines Asphalt Sand

4:1 to 9:1 3:1 to 10:1 4:1 to 6:1

In GA: 2 to 7 In GA: 2 to 8

Crushers: Fines and Shape

point load long load compressionBrazilian4-point load

Test Loading Configurations

010

2030

4050

60

0 25 50 75 100

Loaded Area (%)

Fine

s P

rodu

ced

(%)

Fines Generation

intermediate / long

shor

t / in

term

edia

te rod-like

flaky

cubic

compression

long load and Brazilian

point load

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Shape: Cubicity

Crushing Mode: Shape and Fines

point load

compression

↓

fines

↑

cubicity

↓

fines

↓

cubicity

↑

fines

↑

cubicity

4-point load

Particle Shape - Microphotographs

Sieve 16Sieve 4 Sieve 50 Sieve 100 Sieve 200

Crushed Granite

Crushed Limestone

GDOT Standard Natural Sand

Sieve 16Sieve 4 Sieve 50 Sieve 100 Sieve 200

Sieve 16Sieve 4 Sieve 50 Sieve 100 Sieve 200

Particle Shape: See & Match

sphe

ricity

(Krumbein and Sloss, 1963)

roundness

NASA/JPL

Crater on Mars (April 21, 2004 )

red on left

NASA/JPL

"Berries" on Mars (February 12, 2004)

red on left

NASA/JPL

Core – Martian Rock (August 18, 2004)

red on left

Rice

red on right

Table Salt

Ottawa Sand

Ottawa Sand

Crushed Carbonate

Mica

red on right

Threaded Rubber

Particle size

Particle shape / crushing

emin emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

Volumetric – Gravimetric Relations

MV

ρ =1

v

s

V neV n

= =−

1s s w

dryT

M GV e

ρρ ⋅= =

+

emax

min

maxmin

1

Sd

W S

d

MV

Ge

ρ

ρρ

=

= −

emin

max

minmax

1

Sd

W S

d

MV

Ge

ρ

ρρ

=

= −

(Youd, 1973)

Size and Shape Packing Density

coefficient of uniformity, Cu

1.2

1.0

0.8

0.6

min

imum

em

inm

axim

um e

max

0.8

0.6

0.4

0.2

1 2 3 4 6 10

Mica: bridging & ordering

ordering ordering

bridging bridging

ordering

Particle size

Particle shape / crushing

emin , emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

Geotechnical Engineering Photo Album

Slope Stability

Geotechnical Engineering Photo Album

Slope Stability

Friction Angle in Sands: Simple !

Measure the Angle of Repose

Why Friction Angle?

?

rotational frustration

cv 42 17 Rφ = − ⋅

10

20

30

40

50

0 0.2 0.4 0.6 0.8 1

Roundness R

CS

fric

tion

angl

e

Particle size

Particle shape / crushing

emin , emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

Flow Test: Devices

Flow Test: Procedure

Flow Test: Evolution and Analysis

25

0

0

100[%]D DFD−

= ×

Crushed granite type III "Wetness"

0.42 0.46 0.50 0.54 →

w/c

→FA

/c

2.00

2.75

3.25

4.00

GDOT standard natural sand"Wetness"

0.42 0.46 0.50 0.54 →

w/c

→FA

/c

2.00

2.75

3.25

4.00

0

50

100

150

200

0.5 1.0 1.5 2.0VP/VVFA

Flow

[%]

Increase Flow? Add More Paste

too dry

.

GDOTCrushed granite sand I

How Much Paste? VPaste / VVFA

VPaste / VVFA < 1.0 VPaste / VVFA > 1.0VPaste / VVFA ~ 1.0

controlled by emax

( )max

1FA

CP

VFA

WG G CVFAV e C

⎛ ⎞+⎜ ⎟⎝ ⎠=

Particle size

Particle shape / crushing

emin , emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

Strength – Compression Loading

Before and After Crushing

Strength: Add Paste … but not too much !

GDOT Standard Sand

0

2000

4000

6000

0.5 1.0 1.5 2.0VP/VVFA

Stre

ngth

(psi

)

Crushed Granite Sand II

0

2000

4000

6000

0.5 1.0 1.5 2.0VP/VVFA

Stre

ngth

(psi

)

too much too much

VPaste / VVFA

strength

flowwetdry

+ correlation

Strength and Flow

Particle size

Particle shape / crushing

emin , emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

P-wave velocity

P-wave Signals

P-wave Velocity vs. Compressive Strength

0

1000

2000

3000

4000

5000

0 1000 2000 3000 4000 5000 6000Compressive strength [psi]

P-w

ave

velo

city

[m/s

] .

Crushed granite sand type ICrushed granite sand type IICrushed granite sand type IIINon-GA natural sandCrushed limestone sandGDOT standard sandUnfailed specimen

Strong positive correlation betweenP-wave and strength

Particle size

Particle shape / crushing

emin , emax

Friction angle

Flow test

Strength

P-wave velocity

Thermal properties

http://www.asusmart.com/urbanclimate.php

Cities = Thermal Islands

Baton Rouge, Louisiana

science.nasa.gov

Sacramento, California

science.nasa.gov

Salt lake City, Utah

science.nasa.gov

Thermal Conductivity: Determination

Heating wire

Thermocouple

Volt-meter

DC Power supply

Amp-meter

Thermal Conductivity: Dry Soilsk

[W⋅m

-1K

-1]

Porosity, n Porosity, n Porosity, n

Ottawa 20/30 sand F110 sand Blasting sand

Crushed sand-I Crushed sand-II Crushed sand-III

k[W

⋅m-1

K-1

]

|Δk/Δn|=0.908 |Δk/Δn|=0.95|Δk/Δn|=0.654

|Δk/Δn|=0.935 |Δk/Δn|=0.811 |Δk/Δn|=1.014

nmax nmin nmin nmin nmax nmax

nmax nmax nmax

Porosity, n Porosity, n Porosity, n

0.20

0.25

0.30

0.35

0.40

0.30 0.35 0.40 0.45 0.50 0.55

0.20

0.25

0.30

0.35

0.40

0.30 0.35 0.40 0.45 0.50 0.550.20

0.25

0.30

0.35

0.40

0.30 0.35 0.40 0.45 0.50 0.55

0.20

0.25

0.30

0.35

0.40

0.30 0.35 0.40 0.45 0.50 0.550.20

0.25

0.30

0.35

0.40

0.30 0.35 0.40 0.45 0.50 0.550.20

0.25

0.30

0.35

0.40

0.30 0.35 0.40 0.45 0.50 0.55

Thermal conductivity: Dry vs. Wet Soils

dry

saturated

water 0.72

ice 2.21

quartz 8.4

0.1

1

10

10 100 1000 10000

Effective vertical stress [kPa]

Ther

mal

con

duct

ivity

[W/m

.K]

closing thoughts

Georgia Tech Research Team

Thank You