Nanotechnology For Road bases

Transcription

1

2 Nanotechnology For Road bases

3 TYPICAL RAD BASE DESIGN Stone Base (WBM / WMM) Granular Subbase (GSB) Subgrade

4 Critical Concerns / Issues

5 WATER A LUBRICANT - PARADX Water acts as a lubricant to compact soil for achieving Proctor Density > 95 % at ptimum Moisture Content Water ingress subsequently weakens the road bases by Reducing frictional values & Lowering resistance to deformation

6 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

7 GD QUALITY SIL Non availability of Good Quality Soil for subgrade with CBR > 2,5,10 & Plasticity Index = / < 10 increases..cost of hauling

8 WATER INGRESS - SIDE SHULDERS / SLPES Water ingress into side shoulders / slopes during rains & floods...weakens subgrade, granular subbase, stone base......leads to undulations, cracks & potholes

9 FREEZE THAW EFFECT IN SPRING SEASN 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

10 FREEZE THAW EFFECT IN SPRING SEASN 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

11 CAN WATERPRFING BE DNE? Stop water ingress Maintain friction value CBR Dry & Wet

12 Terrasil Nanotechnology

13 FEATURES Water soluble Chemically reactive Nano Siliconize surfaces by converting silanol groups (water absorbing) to Alkyl siloxane surfaces (water repellent) Forms Si--Si siloxane bond (mother nature s strongest bond which survives for centuries) Non leachable chemistry Easy spray application

14 THE CHEMISTRY Converts Soils (all types) Water loving (Hydrophilic polar) to Water hating (Hydrophobic non polar) By Nano Modification At room temperatures using aqueous solution

15 THE CHEMICAL ACTIN -H groups make surface very hydrophilic (water loving) H H H H H H H Particle surface S i S i S i S i S i S i S i S i S i S i S i S i S i Soil / clay / Sand / Aggregate surface silicate structure S i Terrasil creates molecular level hydrophobic zone (water repellent) Particle surface S i S i S i S i S i S i S i S i S i S i S i S i S i S i S i S i S i S i S i S i S i 4-6 nm Alkyl Siloxane surface Internal Siloxane bonds Soil / Clay / Sand / Aggregate surface silicate structure after Terrasil reaction

16 SURFACE TENSIN 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

17 SIL CLASSIFICATIN Classification based on particle size & plasticity index G=Gravel, S=Sand, C=Clay, M=Silt, =rganic P=poorly graded, W=well graded, L=Low plasticity, H=High plasticity Classification : ML, CL, L, MH, CH, H, CW, Peat

18 SIL CMPSITIN Element % Composition 46.7 Si 27.0 Al 8.1 Fe 5.0 C (total) 3.0 Ca 6.7 Mg 1.4 All thers ~2.1 Technology works with all silicate containing materials Can be applied to almost all types of soil since 99 % soil contains silicates Waterproofs Bentonite also

19 BENEFITS- MAINTAINS FRICTINAL VALUE Retains strength by maintaining frictional values between silt, sand, clay particles and resists deformation

20 BENEFITS- MAINTAINS BREATHABILITY ne 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

21 Cm/sec BENEFITS- REDUCES WATER PERMEABILITY Permeability reduced by 500 folds CH (Black Cotton) Soil, Khandwa, M P, India

22 CEMENT SIL STABILISATIN 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

23 n Site Quality Control Tests

24 DRP TEST 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

25 CAPILLARY RISE 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 CH Soil Untreated Treated

26 PENETRATIN DEPTH TEST 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

27 Application Methodology for Soil Subgrade

28 APPLICATIN TECHNIQUE Technique Spray Dry Spray, on soil compacted to Proctor Density > 95% at MC First Spray Waterproofs 90-95% of the soil surface Second Spray Waterproofed membrane formation with 100% saturation, deep penetration and micro-cracks waterproofing

29 APPLICATIN METHD Hydro-seeder Sprayer Tank Manual Spraying

30 MULTILAYER ENVELPE - PAVEMENT N EMBANKMENT

31 MULTILAYER ENVELPE - CUT SECTIN PAVEMENTS

32 PAVEMENTS N EMBANKMENT / CUT AREAS BTTM 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

33 PAVEMENTS N EMBANKMENT / CUT AREAS BTTM LAYER SECND 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

34 PAVEMENTS N CUT AREAS BTTM & 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

35 PAVEMENTS N EMBANKMENT / CUT AREAS INTERMEDIATE & TP 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 minutes before starting new earth work, without waiting for complete drying of treated soil

36 PAVEMENTS N EMBANKMENT / CUT AREAS SHULDERS & SIDE SLPES 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.

37 DILUTIN & DSAGE Soil Layer Bottom, Intermediate and Top Shoulders & Side Slopes Soil type (clays & silts) Terrasil : Water (<1000 ppm TDS) Ratio CH & CI 1 kg : 300 liters ML & CL 1 kg : 600 liters ML & CL 1 kg : 600 liters Liter /m 2 or up to saturation No. of Applications

38 Application Methodology for Stone Base

39 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

40 WATER BUND 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

41 DILUTIN & DSAGE WMM WBM Layer n aggregates mix n compacted layer n compacted layer Terrasil : Water (<1000 ppm TDS) Ratio Dosage 1 kg : 500 liters 4-6% by weight No. of applications 1 kg : 500 liters 2 3 liter /m kg : 500 liters 2 4 liter /m 2 2 1

42 Applications

43 APPLICATINS Road bases for asphalt and concrete pavements Dirt Roads Rural, Mining, Waste Sites Solar Farms

44 Executed Projects

45 Runway Extension Subgrade, Enugu Airport, Nigeria Soil surface leveling Untreated compacted soil layer Spraying Waterproofing confirmation

46 Rural Road Vadodara, India Subgrade Untreated compacted bottom layer Spraying Waterproofing confirmation

47 Stone base (WBM), Prime & Tack coat and Asphalt additive 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

48 PST MNSN RAD CNDITIN Untreated Stripped asphalt surface with cracks and depression Treated asphalt surface

49 Thank You