Nanotechnology -...
Transcript of Nanotechnology -...
WATER A LUBRICANT -
PARADOX
Water acts as a lubricant to compact soil for
achieving Proctor Density > 95 % at Optimum
Moisture Content
Water ingress subsequently weakens the road
bases by
Reducing frictional values &
Lowering resistance to deformation
WET & DRY CYCLES
Wet Cycle – Expansion
Absorption & Adsorption of Water in monsoon
increases the diameter of hydrated soil causing
expansion of soil
Dry Cycle – Contraction
Evaporation of water from the wet soil leads to
contraction of soil
Expansion & Contraction of soils cause cracking of
soil bases increasing its vulnerability to water
ingress further
GOOD QUALITY SOIL
Non availability of Good Quality Soil for
subgrade with CBR > 2,5,10 & Plasticity
Index = / < 10 increases ……
…..Cost of hauling
WATER INGRESS -
SIDE SHOULDERS / SLOPES
Water ingress into side shoulders / slopes
during rains & floods …..
….weakens subgrade, granular
subbase , stone base ....
....leads to undulations, cracks &
potholes
Saturation of sub-base as snow melts in spring
Freezing of Upper layers at night, causing the
voids filled with water to expand (water to ice
volume expansion 1.1)
Melting of Ice during the day, creates evacuated
cavities and more water is sucked into these
cavities from the bottom
FREEZE – THAW EFFECT IN
SPRING SEASON
Repetitive freezing & thawing action leads to
formation of expanded cavities
With temperature warming up, the ice melts
and the asphalt layer on top collapses above
the cavities to make a large pothole
Repetitive cycles of freeze thaw during the
spring also create large cracks leading to
faster water ingress during rains
FREEZE – THAW EFFECT IN
SPRING SEASON
Water soluble
Chemically reactive
Nano Siliconize surfaces by converting silanol
groups (water absorbing) to Alkyl siloxane
surfaces (water repellent)
Forms Si-O-Si siloxane bond (mother nature’s
strongest bond which survives for centuries)
Non leachable chemistry
Easy spray application
FEATURES
Converts Soils (all types)
Water loving (Hydrophilic polar) to
Water hating (Hydrophobic non polar)
By Nano Modification
At room temperatures using aqueous solution
THE CHEMISTRY
THE CHEMICAL ACTION
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Particle surface
-OH groups make surface very hydrophilic (water loving)
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Terrasil creates
molecular level
hydrophobic zone
(water repellent)
Particle
surface
4 - 6 nm
Alkyl
Siloxane
surface
Internal
Siloxane
bonds
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Soil / clay / Sand / Aggregate surface silicate structure
Soil / Clay / Sand / Aggregate surface silicate structure after Terrasil reaction
SURFACE TENSION EFFECT
Water molecules remain in droplet form on a
hydrophobic surface
Prevents the water molecule (0.18nm) to enter into
the pore structure(2000nm), as the droplet size
(100,000nm) is larger by an order of magnitude
SOIL CLASSIFICATION
Classification based on particle size & plasticity index
G=Gravel, S=Sand, C=Clay, M=Silt, O=Organic
P=poorly graded, W=well graded, L=Low plasticity,
H=High plasticity
Classification : ML, CL, OL, MH, CH, OH, CW, Peat
Technology works with all
silicate containing
materials
Can be applied to almost
all types of soil since 99 %
soil contains silicates
Waterproofs Bentonite
also
SOIL COMPOSITION
Element % Composition
O 46.7
Si 27.0
Al 8.1
Fe 5.0
C (total) 3.0
Ca 6.7
Mg 1.4
All Others ~2.1
Retains strength by maintaining frictional
values between silt, sand, clay particles and
resists deformation
BENEFITS- MAINTAINS FRICTIONAL
VALUE
BENEFITS- MAINTAINS BREATHABILITY
One Way Barrier – Water drop cannot go in but
Water Vapor can come out
Terrasil being a nano modification keeps the
pores open to allow vapors to escape while
preventing water to come in
BENEFITS- REDUCES WATER
PERMEABILITY
Permeability reduced
by 500 folds
CH (Black Cotton) Soil, Khandwa, M P, India
Cm
/sec
Issue
Cement stabilized soil bases are moisture
susceptible leading to loss of strength with time due
to Alkali Silica Reaction (ASR) & Carbonation
Solution
Terrasil prevents capillary rise and water ingress
from top & sides. It eliminates ASR & Carbonation to
help maintain strength for a longer period
CEMENT SOIL STABILISATION
Put water drops on the treated soil surface
Waterproofing is confirmed if the water drop
remains on surface for at least 15 to 20 min
DROP TEST
Cut 6 inch deep channels and continue to
fill water for 6 to 8 hours
A dry top surface confirms effective
waterproofing & elimination of Capillary rise
CAPILLARY RISE TEST
Untreated Treated
CH Soil
Scratch Terrasil treated top 2 to 5 mm soil surface
& put water drops on the scratched surface
Retention of the water repellency confirms effective
depth of waterproofing
Continue scratching and testing as above to arrive at
actual depth of waterproofing achieved
PENETRATION DEPTH TEST
Technique Spray – Dry –Spray, on soil
compacted to Proctor Density > 95% at OMC
First Spray Waterproofs 90- 95% of the soil
surface
Second Spray Waterproofed membrane
formation with 100% saturation, deep
penetration and micro-cracks waterproofing
APPLICATION TECHNIQUE
PAVEMENTS ON EMBANKMENT /
CUT AREAS – BOTTOM LAYER
FIRST SPRAY
Embankment Pavement
Spray Terrasil solution on the compacted bottom layer
and sun dry for 1 to 3 hours
Pavement on Cut Area
Dig trench as specified (min. 400 mm). Spray Terrasil
solution on the compacted bottom layer & vertical side
walls (from the top edge) and sun dry for 1 to 3 hours
PAVEMENTS ON EMBANKMENT /
CUT AREAS – BOTTOM LAYER
SECOND SPRAY
Spray Terrasil solution on the treated layer and allow it
to fully dry. Complete drying of the bottom layer is
critical to stop capillary rise especially in semi-wet
areas
Do Drop Test to confirm that the surface is dried
Lack of repellency indicates incomplete drying. Ensure
complete drying and passing of the Drop Test before
laying next layer
PAVEMENTS ON CUT AREAS –
BOTTOM & INTERMEDIATE & LAYERS
VERTICAL WALL
Saturate 15 cm of the top edge of the cut area and the
vertical walls with the spray dry spray technique
for every layer
Let the run down of the spray be absorbed at the
bottom
Sun dry and check for water repellency by Drop Test
It is critical to dry the bottom layer completely, since it
is the key to stop capillary rise especially in semi-wet
areas
PAVEMENTS ON EMBANKMENT /
CUT AREAS – INTERMEDIATE & TOP
LAYERS
Waterproof with the Spray-Dry-Spray technique
the intermediate and top compacted layers and
vertical side walls from top edge (in case of cut
area)
Dry the treated layers for 30-60 minutes before
starting new earth work, without waiting for
complete drying of treated soil
PAVEMENTS ON EMBANKMENT / CUT
AREAS – SHOULDERS & SIDE SLOPES
Spray Terrasil solution on compacted side slopes till
saturation and allow it to dry
Do the second spray on the treated layer till
saturation and allow it to dry
Cover the treated slopes and build shoulders with
regular soil
For extra binding of the side slopes mix 5 kgs of
cationic asphalt emulsion binder with 100 liters
Terrasil solution.
DILUTION & DOSAGE
Soil Layer Soil
type
(clays &
silts)
Terrasil :
Water
(<1000 ppm
TDS) Ratio
Liter /m2
or up to
saturation
No. of
Applications
Bottom,
Intermediate
and Top
CH & CI 1 kg : 300
liters
1.5–3 2
ML & CL 1 kg : 600
liters
1-2 2
Shoulders &
Side Slopes
ML & CL 1 kg : 600
liters
2–3 2
WET MIX MACADAM (WMM) –
FULL DEPTH
Use Terrasil solution to prepare the specified WMM,
compact and allow the stone base to dry completely
Saturate the top surface with Terrasil solution and
allow it to dry
WATER BOUND MACADAM (WBM) -
SURFACE
Saturate spray Terrasil solution on top surface of the
compacted stone base layer and dry for 3 to 4 hours
Spray Terrasil solution again on the treated layer. Dry
completely to form a waterproofed breathable
membrane
DILUTION & DOSAGE
Layer Terrasil : Water
(<1000 ppm
TDS) Ratio
Dosage No. of
applications
WMM
On
aggregates
mix
1 kg : 500 liters 4 - 6% by
weight
1
On
compacted
layer
1 kg : 500 liters 2 – 3 liter /m2 1
WBM
On
compacted
layer
1 kg : 500 liters 2 – 4 liter /m2 2
Road bases for asphalt and concrete
pavements
Dirt Roads – Rural, Mining, Waste Sites
Solar Farms
APPLICATIONS
Runway Extension Subgrade,
Enugu Airport, Nigeria Soil surface leveling Untreated compacted soil layer
Spraying Waterproofing confirmation
Rural Road Vadodara, India
Subgrade
Untreated compacted
bottom layer Spraying Waterproofing
confirmation
WBM after two
compacted soil layers Compacted WBM
Terrasil Prime coat with
bitumen emulsion
Waterproofing
confirmation
Zycosoil Tack coat with
bitumen emulsion
Compaction of
Zycosoil asphalt layer
Stone base (WBM), Prime &
Tack coat and Asphalt additive
POST MONSOON ROAD CONDITION
Treated asphalt surface
Untreated – Stripped asphalt surface with cracks and depression