Mord specifications for low volume roads
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Transcript of Mord specifications for low volume roads
Presentation outline• Pavements and requirements• Road Construction Materials and tests • Embankment Requirements• Subgrade Requirements• Granular Sub Bases, Bases &
Surfacing Requirements• Bituminous Surfacing Courses
Requirements
Pavement• A pavement is a man-made structure whose
primary function is to spread the load of a vehicle sufficiently that the underlying soil can support it without excessive deformation.
Requirements of Pavements Structural Requirements
Traffic loads Load repetition Climatic variables (rainfall &
temperature) Environmental factors
Riding comfort Economic operation Safe operation
Functional Requirements
Tests for Soil with IS codesType of test Test MethodWater Content IS 2720-2 (1973)
Free Swell Index Of Soil IS 2720-40 (1977)
Plastic Limit Of Soil IS 2720-5 (1985)
Liquid Limit Of Soil IS 2720-5 (1985)
Particle Size Distribution Of Soil IS 2720-4 (1985)
The Specific Gravity Of Soil IS 2720-3-1 (1980)
The In-Situ Dry Density Of Soil By Sand Replacement Method IS 2720-28 (1974)
The In-Situ Dry Density Of Soil By Core Cutter Method IS 2720-29 (1975)
The Maximum Dry Density And The Optimum Moisture Content Of Soil IS 2720-7 (1980)
Embankment ConstructionSuitable Material
1. Soil, moorum, gravel, a mixture of these or other
material approved by the Engineer.
2. It shall be free from logs, stumps, roots, rubbish, etc
3. The size of coarse material shall not ordinarily exceed 75
mm when placed in embankment
4. The maximum particle size not more than 2/3 of the
compacted layer thickness.
Minimum Density Requirement For Suitability Of EmbankmentType of Work Max. laboratory dry unit weight
(IS:2720, Part 7)(a)Embankment not subject to
1) flooding height upto 3 m 2) height more than 3 m
Not less than 14.4 kN/m3Not less than 15.2 kN/m3
(b) Embankment subject to flooding
Not less than 15.2 kN/m3
Type of work / Material Relative compaction % of maximum laboratory dry density obtained by standard proctor test as per IS:2720(Part 7)
Embankment Not less than 90% - 95%Expansive Clays 90% - 95%
Unsuitable Materials
• Material from swamps, marshes and bogs
• Peat, log, stump and perishable material; soil classified as OL,
OI, OH or Pt as per IS:1498.
• Materials susceptible to spontaneous combustion
• Clay having liquid limit exceeding 70 and plasticity index
exceeding 45
• Material with salts resulting in leaching action e.g. sodic soils (pH
> 8.5)
• Expansive clay with free swelling index exceeding 50 per cent
Embankment Construction
Embankment Construction
Unsuitable Materials
• Materials in a frozen condition
• Fill materials with a soluble sulphate content
exceeding 1.9 gm of sulphate, (expressed as SO3)
per litre.
• Material with a total sulphate content (expressed
as SO3) exceeding 0.5 per cent by mass.
Embankment Construction
Construction Operations• Setting out• Dewatering• Stripping of topsoil• Preparing foundation• Spreading and Moisture control• Compaction• Repairs of damages caused by rain/spillage of water• Embankment around structures
Subgrade Construction• Soil, moorum, gravel, a mixture of these or any other
approved material.
• Material considered unsuitable for embankment
construction shall not be used for sub-grade.
• The material for subgrade shall be non-expansive in nature
• Where an expansive clay with acceptable “free swelling
index” value is used as a fill material in embankment, the
sub-grade and top 500 mm portion of the embankment just
below the sub-grade shall be non-expansive in nature.
Subgrade Construction• The size of coarse material in the soil shall ordinarily not
exceed 50 mm when placed in the subgrade.
• Any fill material which yields a maximum dry laboratory unit
weight of less than 16.5 kN/m3 determined as per IS:2720
(Part 7) shall be considered unsuitable for use in subgrade.
• Moisture content: +1% or -2% of OMC
• Relative Compaction: 100%
Existing sub grade: • If sub grade CBR is less than 2%, a capping layer of 100mm
thick with 10% CBR soil is to be provided and a CBR of 2% is to be taken for crust design
Subgrade Construction
Construction operations• Setting out• Dewatering• Stripping of Top soil• Spreading • Moisture control• Compaction
Tests for Aggregates with IS codesProperty of Aggregate Type of Test Test Method
Crushing strength Crushing test IS : 2386 (part 4)
Hardness Los Angeles abrasion test IS : 2386 (Part 5)
Toughness Aggregate impact test IS : 2386 (Part 4)
Durability Soundness test IS : 2386 (Part 5)
Shape factors Shape test IS : 2386 (Part 1)
Specific gravity and porosity
Specific gravity test and water absorption test IS : 2386 (Part 3)
Adhesion to bitumen Stripping value of aggregate IS : 6241-1971
Abrasion testing Internal Dia 700mm, and Length
500mm Abrasive Charges of Cast Iron
with 48mm Dia weighing 390 - 445 gms
Quantity of Aggregates 5 – 10 Kg (Depending upon the size of aggregates taken)
Cylinder Speed 30 – 33 Rpm No. of Revolutions 500 – 1000
(Depending upon the size of the aggregates taken)
Passing 1.7mm sieve
AGGREGATE IMPACT TESTING
• Material passing 12.5 mm sieve and retained on 10 mm sieve• 3 Layers in measuring cylinder, each layer given 25 tamping• Transfer entire material at once to test cylindrical cup, 25 tamping• 15 blows with hammer• Material passing 2.36 mm sieve• Impact value = ( W2 / W1 ) * 100
• Surface Courses……… max 30%• Base courses…………..max 40%• Sub-base courses…….max 50%
Granular/Gravel Sub-Base• Natural sand, moorum, gravel, crushed stone, crushed slag,
brick metal and kankar.
• Min CBR 20%
• Wet AIV < 50% layer thickness :100mm compacted with
smooth wheeled roller ,225 mm compacted with vibratory
roller.• Should free from organic or deleterious materials.• The granular subbase materials shall conform to the
gradings.
Granular Sub-base
IS Sieve Size Per cent by Weight Passing the IS Sieve
Grading I Grading II Grading III75 mm 100 - -53 mm - 100 26.5 mm 55-75 50-80 1009.50 mm - - -4.75 mm 10-30 15-35 25-452.36 mm - - -0.425 mm - - -
0.075 mm < 10 < 10 < 10
Table :Grading for granular sub-base materials
On clayey subgrades where otherwise drainage condition are encountered,
the percent passing IS Sieve 0.075 mm shall not exceed 5
Where naturally occurring gravel is specified for sub-base it shall conform to following grading.
Sieve Designation Per cent by Weight Passing the IS Sieve Grading I Grading II
53 mm 100 -
37.5 mm 100 -
26.5 mm 75-95 -
19.0 mm 80-100 -
9.5 mm 40-75 55-80
4.75 mm 30-60 40-60
425 µ 15-30 15-30
0.075 < 15 < 15
The subbase gravel should have minimum CBR of 20 %
Physical Requirements of Materials for Sub-baseClimate Liquid limit Plasticity
IndexRemarks
Rain fall >1000 mm < 35 <10 up to 1 msa
Rain fall < 1000 mm <40 <15 to 1 msa
All areas respect of rain fall
<25 <6 Design Traffic > 1 msaWet AIV Shalll not exceed 50
The subbase shall have a min soaked CBR of 20 at FDDWhen Locally available morrum are used in the GSB it shall be ensured through adeqate test son represenative samples thatall the requirements meets.
Note: Subbase materials req CBR is not met within economical leads than satisfying all the Grading and other requirements 15 CBR is allowed.
Gravel/Soil-aggregate Base And Surface Course
• Natural gravel/ soil-aggregate or blended with suitable
aggregate fractions of stone, gravel, moorum, sand or
combination of these materials depnding of grading
requirement.
• Wet Aggregate Impact Value (IS:5640) shall not exceed 40
and 30 when used in base and 30 when used in surfacing.
• Flakiness Index (IS:2386 Part I) shall not exceed 25
percent when used in base and 20 when used in surfacing.
Gravel/Soil-aggregate Base And Surface Course– In high rainfall areas (annual rainfall of 1500 mm or
above), coastal areas and where local soils are salt infested, if the water absorption value of the coarse aggregate is greater than 2 percent, the Soundness test shall be carried out on the material delivered to the site as per IS:2386 (Part 5).• Loss with Sodium Sulphate, 5 cycles : 12 per cent
maximum• Loss with Magnesium Sulphate, 5 cycles : 18 per
cent maximumFine aggregates material passing 4.75 mm sieve shall consist of natural or crushed sand and fine mineral particles.
Gravel/Soil-Agg Base and Surface Course
IS Sieve desperation Per cent by Weight Passing IS SieveGrading A Grading B Grading C
53 mm 100 37.5 mm 97–100 100 26.5 mm 97–100 10019 mm 67–81 97–1009.5 mm 56–70 67 – 794.75 mm 33–47 39–53 47 – 59425 µ 10–19 12–21 12 – 2175 µ 4.0-15 4.0–15 4.0–15
The Liquid Limit shall not exceed 25 and PI shall not exceed 6.
Grading requirements for soil-aggregate mixtures for sub-base/base
Sieve size % by mass passing IS sieve Grading designation nominal maximum size
80 mm 40 mm 20 mm80 mm 100
40 mm 97-100 100
20 mm 60-80 80-100 100
10 mm 45-65 55-80 80-100
4.75 mm 30-50 40-60 50-75
2.36 mm - 30-50 35-60
600 µm 10-30 15-30 15-35
75 µm 5-15 5-15 5-15
Grading requirement for surface gravel
IS Sieve Designation
Per cent by Weight Passing IS Sieve
26.5 mm 100
19 mm 97–100
4.75 mm 41 – 71
425 µm 12-28
75 µm 9 – 16
Grading and plasticity index requirements for surface course
Gravel/Soil aggregate for surface course should satisfy
Climate Liquid limit Plasticity Index
High Rain fall >1500 mm
35 4-9
Med Rain fall 750-1500mm
40 6-15
Low rain fall<750 mm
55 15-30
IS SievePercent by mass
passing designated sieve nominal
maximum size 10 mm
10 mm 100
4.75 mm
80-100
2.36 mm
50-80
1.18 mm
40-65
600 µm -
300 µm 20-40
75 µm 10-25
Lime treated soil for improved subgrade/ sub base
• The PI of the soil to be treated should generally be higher than 10.
• Lime for lime-soil stabilization work shall be commercial dry lime slaked at site or pre-slaked lime delivered to the site in suitable packing
• The lime shall have purity of not less than 70% by weight of CaO when tested in accordance with IS:1514
• The water to be used for lime stabilization shall be clean and free from injurious substances. Potable water shall be preferred.
Table : Lime Content For Different Type Of Soil
Soil type required Alluvial soils and Moorum (PI : 10-15) 3%
Clays/ BC soil of medium plasticity (PI : 15-30) 3-5%
Highly expansive Clays (PI : over 30 ) 5-6%
Table : Soil Pulverisation Requirements For Lime Stabilization
Is sieve Minimum % by weight passing the IS sieve
26.5 mm 1005.6 mm 80
CEMENT TREATED SOIL SUBBASE AND BASE
• Sand, gravel, laterite, kankar, brick aggregate, crushed rock, slag or flyash or combination of these.
• For use in base course, the Liquid limit and Plasticity Index shall not exceed 45% and 20%.
• Cement: Cement shall comply with the requirements of IS:269, 455 or 1489
• Water: The water for cement stabilization shall be clean and free from injurious substances
• For use in base and sub-base courses, minimum 7-day unconfined compressive strength of 2.76 MPa and 1.7 MPa respectively is required.
CEMENT TREATED SOIL SUBBASE AND BASE
Soil type required Sands/Sandy soils/Soil-Gravels 3-5 %
Silts/Silty clays of low P1 (<15) 4-8%
Clays/black cotton soils 8-15%
Table : Cement content for different type of soil
IS Sieve % by weight passing within the rangeSub- base base
53.0 mm 100
37.5 mm 95-100
19.0 mm 45-100
9.5 mm 35-100
4.75 mm 25-100
600 micron 8-65
300 micron 5-40
75 micron 0-10
Table : Grading limits of material for stabilization with cement
WBM as Sub-Base /Base /Surfacing: Physical Reqs• Water absorption of aggregate > 2 %
Soundness test.• Aggregates like brick bats, kankar, laterite etc.
which get softened in presence of water shall be tested for Aggregate Impact Value under wet conditions in accordance with IS:5640.
Test Sub-base Base SurfacingAI value < 50 < 40 < 30
Flakiness index < 30 < 25 < 20Loss with
Sodium Sulphate < 12% < 12% < 12%Loss with
Magnesium Sulphate
< 18% < 18% < 18%
Grading No. Size Range IS Sieve Designation Per cent by weight passing
1. 90 mm to 45 mm 125 mm 100
90 mm 90-100
63 mm 25-60
45 mm 0-15
22.4 mm 0-5
2. 63 mm to 45 mm 90 mm 100
63 mm 90-100
53 mm 25-75
45 mm 0-15
22.4 mm 0-5
3. 53 mm to 22.4 mm 63 mm 100
53 mm 95-100
45 mm 65-90
22.4 mm 0-10
11.2 mm 0-5
Grading requirements of coarse aggregate for WBM
Grading Classification
Size of Screenings IS Sieve Designation
Per cent by weight passing the IS Sieve
A. 13.2 mm 13.2 mm 100
11.2 mm 95-100
5.6 mm 15-35
180 micron 0-10
B. 11.2 mm 11.2 mm 100
5.6 mm 90-100
180 micron 15-35
Grading for screenings
To fill in voids , generally consist of same materials as the coarse aggregatesEconomic considerations are so warrant predominately non plastic materials (other than rounded river borne) may be used for this purpose and Liquid limit and PI of such materials 20 and 6 respectively. In soft aggregates screening should omitted – likely to crush under rollers.
Wet Mix Macadam Base• Coarse aggregate shall be crushed stone and shall conform to the requirements.• Thickness of the single compacted WMM shall not be < 75 mm.• The Compacted thickness of a single layer of the base course may be up to 200 mm.
Test Test Method Requirements
AIV Value IS:2386 40 % (maximum )
Flakiness Index IS :2386 25 % (maximum )
If water absorption value of coarse aggregate is greater than 2 %, soundness test shall be carried out.
IS Sieve Designation
Maximum percent by weightPassing the sieve
53.00 mm 10045.00 mm 95-10026.50 mm -22.40 mm 60-8011.20 mm 40-604.75 mm 25-402.36 mm 15-30
600 micron 8-2275 micron 0-8
Material finer than 425 micron shall have Plasticity Index (PI) not exceeding 6
Optimum Moisture Content :Optimum Moisture Content shall be determined in accordance with IS:2720 (Part 7)
Table : Grading Requirements
WET MIX MACADAM
The shoulder material should be selected earth with maximum laboratory dry unit weight not less 16.5 kN/m3 . LL and PI not to exceed 25 and
6 respectively
Shoulder
Local material for road construction
• Locally available soils and aggregates
• Transport cost and Economic consideration.
• Construction aspects for the use of these materials are similar to the conventional quality materials.
Sl.No.
State of Occurrence of Material
Manner of Use in the Pavement
Test/Quality Requirements
1.
Kankar, Laterite, Dhandla etc. found
in blocks or large discrete particles.
As WBM without screenings/filler after breaking the material, broadly meeting the required sizes.
Wet Aggregate Impact Value( IS:5640) not to exceed 50, 40 and 30 when used in sub-base, base and surfacing respectively.
2.
Naturally occurring gravels without appreciable amount ofsoil.
Directly as a granular layer for sub-base/base course.
PI should not exceed 6 when used in lower courses. Evaluated for strength by soaked CBR.
3.
Soil-gravel with appreciable amount of soil.
Directly as soil-gravel for sub-bas e /base.
The material should be well-graded and the PI restricted as for Sl. No. 2 above. Evaluated for strength by soaked CBR value.
Table : Physical Requirements For Flyash As A Pozzolana
•Lime should have a purity of not less than 70% by weight of CaO when tested as per IS:1514.Quick lime which has been pre-slaked at site should be used within 7 days. Slaked lime supplied in airtight bags should not be stored for more than 3 months.• Soil should have a PI between 4 and 20; soil with PI more than 20 may be used provided strength requirements are satisfied.• Water should be free from injurious salts, organic matter and other deleterious matter. Potable water is satisfactory.
Aggregate gradation requirement for Crusher Run
Macadam 53mm max size
IS Sieve, mm
Per cent passing by weight
53 mm max size63 10045 87 - 100
22.4 50 - 855.6 25 – 45
0.710 10 - 250.090 2 - 9
MORD - Crusher Run Macadam 53 mm maximum size
AIV < 30% and FIV < 25% for coarse aggregates. LL < 25% & PI < 6%
400-20, Aggregate gradation requirement for Crusher Run Macadam 37.5mm max size
IS Sieve, mm
Per cent passing by weight
37.5 mm max size63 --45 100
22.4 90 - 1005.6 35 - 55
0.710 10 - 300.090 2 - 9
Crusher Run Macadam 37.5mm maximum size
AIV < 40% and FIV < 25% for coarse aggregates. LL < 25% & PI < 6%
Tests for Bitumen with IS codesType of test Test Method
Penetration Test IS: 1203-1978Ductility test IS: 1208-1978
Softening Point test IS: 1205-1978
Specific gravity test IS: 1202-1978
Viscosity test IS: 1206-1978
Flash and Fire Point test IS: 1209-1978
Float Test IS: 1210-1978
Determination of water content IS: 1211-1978
Determination of Loss on heating IS:1212-1978
Prime Coat Over Granular Base
• Application of single coat low viscosity liquid bituminous materials to non bituminous porous granular surface prepared to spread the bituminous treat mix.
• The primer shall be cationic bitumen emulsion ss1 grade and it shall not be applied to wet surface/ during dust/foggy/rainy and windy.
Type of Quantity per 10sqm
Surface (kg)
WBM /WMM 7-10Stabilized Base 9-12Gravel base 12-15
Table: Type And Quantity Of Cutback Bitumen Primer
Weather and seasonal limitations• Shall not be applied to a wet surface or during a dust storm or when the weather is foggy, rainy or windy or when the temperature in the shade is less than 10 degrees Celsius.• Surface should be free from standing water and shall be just damp.
Type of surface Type of cutback
Rate of spray(kg/m^2)
WMM/WBM MC 30 0.6-0.9Mechanical stabilized soil base, lime stabilized soil, soil cement and lime cement base
MC 70 0.9-1.2
Gravel base , crusher run macadam and crushed rock base
MC 250 1.2-1.5
Tack coat
Type of Surface Quantity of emulsion per sqm area (kg)
Normal Bituminous surfaces 0.20 to 0.25
Dry and hungry bituminous surfaces 0.25 to 0.30
Granular (primed) 0.25 to 0.30
Cement Concrete Pavement 0.30 to 0.35
Binder for Tack Coat:Rapid setting bituminous emulsion Grade RS-1 complying with IS:1887 as specified in Contract. For sites at sub-zero temperature: Cutback Bitumen (Medium Curing Grade) asper IS:217.
Table : Rate of application of Binder
BITUMINOUS MACADAM• A paving bitumen of viscosity graded complying
with IS:73• Crushed rock, crushed gravel or other hard
material retained on the 2.36 mm sieve.• Clean, hard, durable, of cubical shape , free from
dust and soft or friable matter , organic or other deleterious substance.
Lowest daily mean Air temperature, °C
Highest daily mean Air temperature °C
Less than 20 °C 20 to 30 °C More than 30 °C
More than -10 °C VG -10 VG -20 VG -30
-10 °C or lower VG -10 VG -10 VG -20
BITUMINOUS MACADAM
Property Test Specification
Particle shape Flakiness index (IS:2386 Part 1) Max. 25 %
Strength Aggregate Impact Value (IS:2386 Part 4)
Max. 30 %
Durability Soundness (IS:2386 Part 5) Sodium sulphate Max. 12 %
Magnesium sulphate Max. 18 %
Water absorption Water Absorption (IS:2386 Part 3) Max. 2 %
Stripping
Coating and stripping of bitumen
aggregatemixture. (IS:6241)
Minimum retainedcoating 95 %
Physical requirement for aggregates for bituminous macadam
Composition of bituminous MacadamIS Sieve (mm) Cumulative Per cent Passing
by weight of Total Aggregate26.5 10019 90-10013.2 56-884.75 16-362.36 4-190.3 2-100.075 0-5Bitumen content, % by weight of total mixture
3.3-3.5
Bitumen Viscosity Grade VG-10 to VG-30
BITUMINOUS MACADAM
Surface dressingBitumen:• Viscosity grade bitumen (IS 73)• Modified bitumen (IS 15462)• Rapid setting bitumen emulsion (IS 8887)
Lowest daily mean Air temperature, °C
Highest daily mean Air temperature °C
Less than 20 °C 20 to 30 °C More than 30 °C
More than -10 °C VG -10 VG -20 VG -30
-10 °C or lower VG -10 VG -10 VG -20
Surface dressing
Property Test Specification
Particle shape Flakiness index (IS:2386 Part 1) Max. 25 %
Strength Aggregate Impact Value (IS:2386 Part 4)
Max. 30 %
Durability Soundness (IS:2386 Part 5) Sodium sulphate Max. 12 %
Magnesium sulphate Max. 18 %
Water absorption Water Absorption (IS:2386 Part 3) Max. 1 %
Stripping
Coating and stripping of bitumen
aggregatemixture. (IS:6241)
Minimum retainedcoating 95 %
Physical requirement for aggregates for Surface dressing
GRADING REQUIREMENTS FOR CHIPS FOR SURFACE DRESSING
IS Sieve Designation (mm)
Cumulative percent by weight of total aggregate passing for the following nominal sizes(mm)19 13 10 6
26.5 100 501 502 50319 85-100 100 504 50513 0-40 85-100 100 5069.5 0-7 0-40 85-100 1006.3 507 0-7 0-35 85-1004.75 508 509 0-10 5103.35 511 512 513 0-352.36 0-2 0-2 0-2 0-100.6 514 515 516 0-20.075 0-1.5 0-1.5 0-1.5 0-1.5Minimum 65% by weight of aggregate
Passing 19mm retained 13.2mm
Passing 13.2 mm retained 9.5 mm
Passing 9.5mm retained 6.3 mm
Passing 6.3 mm retained 3.35 mm
20 mm Open graded Premix Surfacing using Bitumen
Property Test Specification
Particle shape Flakiness index (IS:2386 Part 1) Max. 25 %
Strength Aggregate Impact Value (IS:2386 Part 4)
Max. 30 %
Durability Soundness (IS:2386 Part 5) Sodium sulphate Max. 12 %
Magnesium sulphate Max. 18 %
Water absorption Water Absorption (IS:2386 Part 3)
Max. 1 %
Stripping
Coating and stripping of
bitumen aggregatemixture. (IS:6241)
Minimum retainedcoating 95 %
Table : Physical requirements of stone aggregate
Aggregate Quantity(a) Nominal size 13.2 mm (passing 22.4
mm sieve and retained on 11.2 mm sieve)
0.18 m3
(b) Nominal size 11.2 mm (passing 13.2 mm sieve and retained on 5.6 mm sieve)
0.09 m3
Total 0.27 m3
Binder (a) For 0.18 m3 of 13.2 mm nominal size
stone at 52 kg bitumen per m 3
9.5 kg
(b) For 0.09 m3 of 11.2 mm nominal size stone at 56 kg bitumen per m 3
5.1 kg
Total 14.6 kg
Binder: The binder shall be a viscosity grade bitumen of suitable grade and Satisfying the Requirements of IS:73
Table : Quantities of material required for 10 m^2 area
20 mm cold mixed Open graded Premix carpet• The binder for premix carpet shall be bitumen emulsion of Medium
Setting (MS) grade complying with IS:8887 and having a bitumen content of 65% minimum by weight.
• Physical requirements of stone aggregate same as Open graded Premix Surfacing using Bitumen
Aggregate Quantity(a) Nominal size 13.2 mm (passing
22.4 mm sieve and retained on 11.2 mm sieve)
0.18 m3
(b) Nominal size 11.2 mm (passing 13.2 mm sieve and retained on 5.6 mm sieve)
0.09 m3
Total 0.27 m3
Cationic bitumen Emulsion 20-23 kg
Quantities of material required for 10 m^2 area
Mix Seal Surfacing
Lowest daily mean Air temperature, °C
Highest daily mean Air temperature °C
Less than 20 °C 20 to 30 °C More than 30 °C
More than -10 °C VG -10 VG -20 VG -30
-10 °C or lower VG -10 VG -10 VG -20
• The fine aggregates shall be crushed rock, quarry sand, natural gravel/sand or a mixture of both free from organic and deleterious substances
• Binder: The binder shall be a viscosity grade bitumen of suitable grade and Satisfying the Requirements of IS:73
Mix Seal Surfacing
Property Test Specification
Particle shape Flakiness index (IS:2386 Part 1) Max. 25 %
Strength Aggregate Impact Value (IS:2386 Part 4)
Max. 30 %
Durability Soundness (IS:2386 Part 5) Sodium sulphate Max. 12 %
Magnesium sulphate Max. 18 %
Water absorption Water Absorption (IS:2386 Part 3) Max. 1 %
Stripping
Coating and stripping of bitumen
aggregatemixture. (IS:6241)
Minimum retainedcoating 95 %
Table : Physical requirements of stone aggregate
Mix Seal Surfacing
IS sieve designation (mm)
Cumulative percent by weight passing
Type A Type B
13.2 — 100
11.2 100 88 -100
5.6 52 -88 31 -52
2.8 52 -88 5 -25
0.090 0 -5 0 -5
Aggregate Gradation
Seal coat• The seal coat shall be any of the three
types mentioned below:• Type A : Liquid seal coat comprising of
an application of layer of bituminous binder followed by a cover of stone chips.
• Type B : Premixed seal coat comprising of a thin application of fine aggregate premixed with bituminous binder.
• Type C : Premixed seal coat comprising of an application of 6.7 mm size stone chips premixed with bituminous binder.
Type of seal coatPer 10 sq m area
Bitumen in kg Bituminous Emulsion in kg
Type A 9.8 12 to 14Type B 6.8 10 to 12Type C 4.5% by weight of total
mix9 to 11
Table : Quantity And Gradation Requirement Of Aggregate For Seal Coat
Type of seal coat Quantity of aggregate requiredper 10 sqm
area
Gradation requirement
100% passing sieve 100 % retained sieve designation designation
Type A 0.09 cum 11.2 mm 2.36 mmType B 0.06 cum 2.36 mm 180 micronsType C 0.09 cum 9.5 mm 2.36 mm
Table : Quantities of binder required for seal coat