Kishor Kumar

    Absolute Viscosity

    Absolute Viscosity Test of Bitumen as per ASTM D2171

    Bitumen / /

    Absolute Viscosity Test of Bitumen – ASTM D2171 Procedure & Calculation Absolute Viscosity Test of Bitumen Using Cannon-Manning Vacuum Capillary Viscometer (ASTM D2171) The Absolute Viscosity Test of Bitumen is a critical laboratory procedure used to assess the flow characteristics of paving-grade bitumen under controlled temperature and vacuum conditions. This test is essential for highway engineers, laboratory technicians, and quality control professionals who need accurate and reproducible data on bitumen viscosity. Using a Cannon-Manning Vacuum Capillary Viscometer, the test measures the time it takes for a bitumen sample to flow through a capillary tube, which is then converted into absolute viscosity using a calibrated factor. Performing this test correctly ensures that the selected bitumen will perform effectively under traffic loads and varying climatic conditions. 1. OBJECTIVE The main goal of this test is to determine the absolute viscosity of bitumen at a standard temperature of 60 °C under a vacuum of 30 cm Hg. Viscosity measurement is critical for: Ensuring proper workability of asphalt during mixing and laying. Predicting rutting and deformation resistance of pavement. Verifying consistency and quality of paving-grade bitumen. Comparing bitumen from different suppliers. 2. THEORY Bitumen is a viscoelastic material, meaning its resistance to flow depends on temperature and load. The absolute viscosity represents its internal resistance to flow under laminar conditions. The Cannon-Manning Vacuum Capillary Viscometer determines this property by: Allowing bitumen to flow through a narrow capillary under vacuum. Recording the flow time between two calibrated marks. Multiplying the flow time with the viscometer’s calibration factor (K) to calculate viscosity in Poises. Using a vacuum helps remove air bubbles and ensures smooth laminar flow, which is essential for accurate results. The ASTM D2171 standard ensures consistency and repeatability in viscosity measurements across different laboratories and projects. 3. APPARATUS Constant Temperature Bath (water up to 100 °C or silicone oil up to 150 °C) with ±0.1 °C accuracy. Vacuum pump and manometer capable of maintaining 30 cm Hg with ±0.05 cm Hg accuracy. Cannon-Manning Vacuum Capillary Viscometer (Size 12 or 13 depending on bitumen grade). Stopwatch with 0.5-second accuracy. Viscometer stand for holding up to 6 tubes. Thermometer for monitoring sample and bath temperature. Glassware and safety equipment such as tongs, gloves, and goggles. Note: All apparatus should be clean, dry, and calibrated according to the manufacturer’s specifications to ensure accurate measurements. 4. PROCEDURE Sample Collection: Collect a representative bitumen sample (~50 g) in a clean container and stir gently to ensure homogeneity. Heating: Heat the sample to 135 ± 5.5 °C using a water or silicone oil bath. Avoid overheating to prevent oxidation of bitumen. Filling Viscometer: Carefully pour the heated bitumen into the viscometer up to the fill mark (Line E ±2 mm). Standing Period: Let the viscometer stand for 10 ± 2 minutes to allow trapped air bubbles to escape. Immersion in Bath: Place the viscometer in the constant temperature bath maintained at 60 °C. Ensure it is suspended and does not touch the bottom of the bath. Vacuum Application: Connect the viscometer to the vacuum pump and apply 30 cm Hg vacuum. Verify the reading on the manometer. Timing Flow: Start the stopwatch as the bitumen reaches Mark G and stop when it reaches Mark H. Record the flow time (T seconds). Repeat: Perform at least three measurements per sample and calculate the average flow time for accuracy. Tips for Accuracy: Avoid shaking the viscometer, maintain bath temperature ±0.1 °C, and ensure a stable vacuum during the test. 5. CALCULATION Formula for Absolute Viscosity Absolute Viscosity (Poises) = K × T K: Calibration factor of viscometer in Poises/sec (provided by the manufacturer). T: Flow time in seconds from Mark G to Mark H. Example: If T = 250 s and K = 12.5 Poises/sec, then Absolute Viscosity = 12.5 × 250 = 3125 Poises. 6. RESULTS The results should be reported as follows: Sample identification Bath temperature (60 °C) Vacuum applied (30 cm Hg) Flow time (T seconds) Calculated absolute viscosity (Poises) Observations (e.g., bubbles, irregular flow) Sample Temp (°C) Vacuum (cm Hg) Flow Time T (s) Absolute Viscosity (Poises) Bitumen A 60 30 250 3125 Bitumen B 60 30 200 2500 7. FACTORS AFFECTING VISCOSITY Temperature: Viscosity decreases with increasing temperature. Vacuum Accuracy: Inconsistent vacuum affects flow time. Air Bubbles: Entrapped air lowers measured viscosity. Viscometer Calibration: Must match the size and grade of bitumen. Bitumen Grade: Penetration grade and polymer-modified bitumen differ in viscosity. 8. TROUBLESHOOTING Problem Possible Cause Solution Erratic flow Air bubbles trapped in viscometer Let bitumen stand longer or reheat gently Slow flow Sample too viscous or too cold Ensure bath temperature is correct and bitumen is properly heated Vacuum drops Leaks in tubing or joints Inspect vacuum system and seal leaks Temperature fluctuates Faulty thermostat Use calibrated bath and monitor continuously Quick Reference: Absolute Viscosity Test (ASTM D2171) Standard: ASTM D2171 – Viscosity by Vacuum Capillary Viscometer Purpose: Measure flow resistance of bitumen at 60°C under vacuum Vacuum: 30 cm Hg (±0.05 cm Hg) Test Temperature: 60°C (accuracy ±0.1°C) Viscometer: Cannon-Manning (Size 12/13) Sample Heating: 135 ±5.5 °C before filling Flow Timing: Between Mark G → H Viscosity Formula: Absolute Viscosity = K × T Top FAQs – Absolute Viscosity Test of Bitumen (ASTM D2171) What is the Absolute Viscosity Test? It determines bitumen’s resistance to flow at 60°C using a vacuum capillary viscometer under 30 cm Hg vacuum, providing reliable QC data. Why is vacuum used? To remove air bubbles and ensure laminar flow, reducing measurement errors. Which viscometer is used? Cannon-Manning Vacuum Capillary Viscometer, typically Size 12 for paving grades. What is the test temperature? 60°C ±0.1°C to simulate typical bitumen service temperature. How is viscosity calculated? Viscosity = K × T, where K is the calibration factor and T is flow time in seconds. Minimum heating temperature? 135 ±5.5°C to ensure proper flow and eliminate lumps. Standing time after filling? 10 ±2 minutes to allow air bubbles to escape. Precision for timing? Stopwatch accurate to ±0.5 sec for reliable results. Typical viscosity values? 800–4000 Poises at 60°C for paving bitumen. Why 60°C? Reflects bitumen’s

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    Bitumen

    Ductility Test

    Bitumen / /

    Ductility Test of Bitumen – IS 1208 Procedure, Apparatus & Results Ductility Test of Bitumen – IS 1208 Complete Guide The ductility test measures the stretching capacity of bitumen under tensile load before failure. It is a key parameter for evaluating flexibility and crack resistance in flexible pavements. Fig: Ductility test process flow Objective To determine the ductility of bituminous material i.e. its ability to stretch without breaking under standard test conditions. Apparatus Required Ductility testing machine Briquette mould Water bath (temperature controlled) Thermometer Hot knife / spatula Fig: Briquette mould assembly Sample Preparation Heat the bituminous material until it becomes completely fluid. Filter the molten bitumen through a 90-micron sieve to remove impurities. Assemble the briquette mould on a clean brass plate. Coat the brass plate and inner surfaces of the mould with a mixture of equal parts glycerine and dextrine to prevent sticking. Pour the molten bitumen slowly in a thin continuous stream from end to end of the mould until slightly overfilled. Allow the specimen to cool at room temperature for 30–40 minutes. Place the mould assembly in a water bath maintained at the specified temperature for 30 minutes. Level the surface using a hot straight-edged knife or spatula to make the mould exactly flush. Procedure (IS Standard Method) Step 1 – Standard Test Conditions Unless otherwise specified, the ductility test shall be conducted at a temperature of 25.0 ± 0.5°C and at a pulling rate of 50.0 ± 2.5 mm/min. Step 2 – Low Temperature Ductility Test When low-temperature ductility is required, the test shall be performed at 4.0 ± 0.5°C with a pulling rate of 10.0 ± 0.5 mm/min. Step 3 – Mould Conditioning Place the brass plate with mould and sample in a water bath maintained at the specified temperature. Keep it for 85–95 minutes for proper conditioning before testing. Step 4 – Specimen Preparation Remove the briquette carefully from the water bath and detach the side plates without disturbing the specimen. Step 5 – Mounting in Machine Immediately fix the specimen in the ductility testing machine by attaching the clips without applying any initial strain. Step 6 – Test Execution Pull the two clips horizontally at a uniform rate of 50 ± 2.5 mm/min until rupture occurs. Step 7 – Test Conditions Control Ensure the specimen remains fully submerged in water during the test. Water level must be at least 25 mm above and below the specimen, and temperature must remain within ±0.5°C. Result The ductility value is the distance in centimeters through which the bitumen thread stretches before breaking. Interpretation of Results High ductility: Indicates flexible, durable, and crack-resistant pavement performance. Low ductility: Indicates brittle bitumen with higher risk of pavement cracking. Limits of Ductility A35 & S35 grade bitumen: Minimum 50 cm at 27°C Other paving grades: Minimum 75 cm at 27°C Importance Ensures pavement flexibility Prevents thermal cracking Improves service life Essential for QA/QC testing Conclusion Ductility test ensures bitumen has sufficient elongation capacity to withstand traffic loads and temperature variations in highway construction. Precautions 1. If the bituminous material comes in contact with the surface of water or touches the bottom of the water bath during the test, the result shall not be considered normal. In such cases, the specific gravity of the water in the bath shall be adjusted by adding either methyl alcohol or sodium chloride, so that the bituminous material neither floats on the surface nor touches the bottom of the bath at any time during the test. 2. The plate on which the mould is placed shall be perfectly flat and level so that the bottom surface of the mould remains in full contact throughout the test. 3. While filling the mould, care shall be taken not to disturb the mould assembly, as this may distort the briquette. It shall also be ensured that no air pockets are trapped within the moulded specimen. 4. If a normal test result is not obtainable in three successive attempts, the ductility shall be reported as “unobtainable under the conditions of test.” FAQs What does ductility indicate? It indicates the ability of bitumen to stretch without breaking. Why is ductility important? It prevents cracking and improves pavement flexibility. Standard temperature? 25–27°C as per IS 1208. How is ductility measured? In centimeters of elongation before rupture.

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    Bitumen
    bitumen extraction

    Bitumen Extraction Test – Objective, Procedure & Calculation

    Bitumen, Bituminous Work / /

    The Bitumen Extraction Test is a laboratory method used to determine the actual bitumen content present in a bituminous mix by separating the binder from aggregates using a suitable solvent. This test is essential for quality control, mix design verification, and compliance with MoRTH / IS:2720 (Part 2) and ASTM standards. Accurate bitumen content ensures proper pavement durability, strength, and resistance to deformation.

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    Bitumen, Bituminous Work
    flakiness and elongation guage

    Flakiness & Elongation Test

    Aggregate / /

    Flakiness & Elongation Index Test – Method Statement Flakiness & Elongation Index Test – IS 2386 Procedure with Calculation Procedure • Apparatus • IS Sieve Table • Results format OBJECT Assess aggregate particle shape quality using the Flakiness & Elongation Index Test as per IS 2386 (Part I). This essential aggregate shape test determines the percentage of flaky and elongated particles that can adversely affect compaction, interlocking, and overall pavement performance. Excessive flaky and elongated aggregates reduce load-bearing capacity, increase voids, and lead to premature failures such as rutting, cracking, and surface deformation in flexible pavements. Therefore, strict compliance with IS specifications is critical for ensuring structural durability and long service life. This practical, site-ready guide covers: Required apparatus and gauge dimensions Step-by-step laboratory procedure Calculation formulas for Flakiness Index (FI) and Elongation Index (EI) Permissible limits as per MoRTH and IS standards Interpretation tips for QA/QC engineers Designed specifically for site engineers, QA/QC teams, and highway professionals, this guide ensures accurate testing, proper documentation, and informed decision-making for high-performance pavement construction. APPARATUS The apparatus for the shape tests consists of the following: A standard thickness gauge A standard length gauge IS sieves of sizes: 63, 50, 40, 31.5, 25, 20, 16, 12.5, 10 and 6.3 mm A balance of capacity 5 kg, readable and accurate up to 1 g The particle shape of aggregates is determined by the percentages of flaky and elongated particles contained in it. For base course and construction of bituminous and cement concrete types, the presence of flaky and elongated particles are considered undesirable as these cause inherent weakness with possibilities of breaking down under heavy loads. Thus, evaluation of shape of the particles, particularly with reference to flakiness and elongation is necessary. The Flakiness Index of aggregates is the percentage by weight of particles whose least dimension (thickness) is less than three-fifths (0.6 times) of their mean dimension. This test is not applicable to sizes smaller than 6.3 mm. The Elongation Index of an aggregate is the percentage by weight of particles whose greatest dimension (length) is greater than nine-fifths (1.8 times) their mean dimension. This test is also not applicable for sizes smaller than 6.3 mm. PROCEDURE Sieve the sample through the IS sieves (as specified in the table). Take a minimum of 200 pieces of each fraction to be tested and weigh them or take the maximum number of pieces available up to 200 Nos. In order to separate the flaky materials, gauge each fraction for thickness on a thickness gauge. The width of the slot used should be of the dimensions specified in column (4) of the table for the appropriate size of the material. Weigh the flaky material passing the gauge to an accuracy of at least 0.1 per cent of the test sample. In order to separate the elongated materials, gauge the non-flaky material for length on a length gauge. The width of the slot used should be of the dimensions specified in column (6) of the table for the appropriate size of the material. Weigh the elongated material retained on the gauge to an accuracy of at least 0.1 per cent of the test sample. … IS SIEVE & GAUGE TABLE Passing through IS Sieve, mm Retained on IS Sieve, mm Weight of fraction (200 pieces), g Thickness gauge size, mm Weight passing thickness gauge (Xi) Length gauge size, mm Weight retained on length gauge (Yi) 63 50 W1 23.90 X1 – – 50 40 W2 27.00 X2 81.00 Y1 40 31.5 W3 19.50 X3 58.00 Y2 31.5 25 W4 16.95 X4 – – 25 20 W5 13.50 X5 40.5 Y3 20 16 W6 10.80 X6 32.4 Y4 16 12.5 W7 8.55 X7 25.5 Y5 12.5 10 W8 6.75 X8 20.2 Y6 10 6.3 W9 4.89 X9 14.7 Y7 Total W = X = Y = OBSERVATIONS and: FORMULAE Record every fraction’s weights clearly. Use at least two significant figures for percentages and record sample piece counts. Flakiness Index = ((X1 + X2 + …) / (W1 + W2 + …)) × 100 Elongation Index = ((Y1 + Y2 + …) / (W1 + W2 + …)) × 100 Fraction Total pieces taken (Wi) Flaky weight (Xi) Elongated weight (Yi) Remarks 63–50 mm 50–40 mm 40–31.5 mm 31.5–25 mm 25–20 mm 20–16 mm 16–12.5 mm 12.5–10 mm 10–6.3 mm Total RESULT I. Flakiness Index = X II. Elongation Index = Y NOTES & REFERENCES This document preserves the original technical content. Do not alter the definitions if your contract specification references a specific IS edition. Reference: IS 2386 Part 1 – Methods of Test for Aggregates for Concrete (Particle Shape Tests). Record environmental conditions and the balance calibration status with every test batch for traceability. Permissible Limits as per MoRTH Application Combined FI + EI Limit Bituminous Concrete (BC) ≤ 30% Dense Bituminous Macadam (DBM) ≤ 35% Wet Mix Macadam (WMM) ≤ 35% Note: Always verify latest MoRTH revision applicable to your contract. Document: • Generated: 20 Nov 2025 Enter Values to Calculate Indices W Values X Values Y Values Calculate Results: Flakiness Index: 0% Elongation Index: 0% Quick Reference: Flakiness & Elongation Index Test Applicable Aggregate Size: Only aggregates ≥6.3 mm are tested. Minimum Sample Count: 200 pieces per sieve fraction (or maximum available). Flakiness Index Criterion: Particles with thickness < 0.6 × mean size. Elongation Index Criterion: Particles with length > 1.8 × mean size. Required Gauges: Thickness gauge for flakiness; Length gauge for elongation. Accuracy: Weigh materials to at least 0.1% accuracy of sample weight. Outcome: FI = (Flaky Weight / Total Weight) × 100; EI = (Elongated Weight / Total Weight) × 100. Purpose: Ensures aggregates are suitable for pavement and concrete strength requirements. Top FAQs – Flakiness & Elongation Index Test What is the minimum aggregate size for these tests? Aggregates smaller than 6.3 mm are not tested. Why are flaky and elongated particles undesirable? They reduce pavement strength and break easily under heavy loads. How many aggregate pieces must be tested?

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    Aggregate
    cube testing machine

    Compressive Strength of Concrete Cube Test (IS 516 Guide)

    Concrete Work / /

    Concrete Cube Test – IS 516 Procedure, Compressive Strength & Formula 1. Objective The Concrete Cube Test as per IS 516 is the standard method used to determine the compressive strength of concrete for pavements, buildings, bridges, and structural elements. It verifies whether the concrete supplied at site meets the specified grade requirements and ensures structural safety and durability. This test involves preparing, casting, curing, and testing concrete cube specimens of size 150 × 150 × 150 mm or 100 × 100 × 100 mm to determine compressive strength at specified ages — typically 7 days (early strength assessment) and 28 days (characteristic strength verification). The procedure includes: Proper mould preparation and oiling Sampling of fresh concrete as per standard practice Layer-wise filling and compaction (tamping/vibration) Initial setting period and demoulding after 24 ± ½ hours Water curing under controlled temperature conditions Compression testing using a calibrated Compression Testing Machine (CTM) Calculation of compressive strength (Load / Cross-sectional Area) Accurate execution of cube testing ensures: Verification of concrete grade (M20, M25, M30, etc.) Early detection of batching or mix design issues Compliance with project specifications and quality control norms Long-term durability and structural performance Designed for site engineers, QA/QC teams, laboratory technicians, and project managers, this guide provides practical, step-by-step instructions to ensure reliable results and compliant construction practices. 2. Apparatus Required Cube moulds – 150 mm or 100 mm Mixing tray and scoop Tamping rod (16 mm diameter) Trowel Concrete mixer (if required) Curing tank (27 ± 2°C) Compression Testing Machine (CTM) 3. Preparation of Cube Moulds Clean moulds to remove dust and hardened mortar. Assemble moulds properly and tighten bolts. Apply thin uniform oil layer on internal faces. Check alignment and squareness of mould. 4. Sampling and Mixing of Concrete Sample concrete from freshly mixed batch. Mix thoroughly until uniform colour and consistency are achieved. Start casting immediately to avoid loss of workability. 5. Casting of Concrete Cubes Fill mould in three equal layers. Distribute concrete evenly around mould. 6. Compaction of Concrete Compact each layer by rodding or vibration. Manual compaction: 35 strokes per layer. Rods to penetrate into the previous layer. Tap mould sides gently to remove air voids. Finish top surface smoothly using trowel. 7. Identification and Initial Storage Date of casting Grade of concrete Cube number / location Store cubes undisturbed for 24 hours at 27 ± 2°C. 8. Curing of Concrete Cubes Demould cubes after 24 ± ½ hours. Immediately immerse in clean water. Maintain curing temperature at 27 ± 2°C. Continue curing till testing age. 9. Compression Testing of Cubes (IS:516) Remove cube from curing tank (SSD condition). Clean cube and CTM platens. Measure dimensions (nearest 0.2 mm). Place cube centrally on CTM platen. Apply load gradually at ≈140 kg/cm²/min. Record maximum load at failure. Note: Improper centring causes eccentric loading and wrong test results. 10. Calculation of Compressive Strength Compressive Strength (N/mm²) = Maximum Load at Failure ÷ Loaded Area 11. Cube Size – Area – Thumb Rules Cube Size Loaded Area 150 mm Cube 225 cm² 100 mm Cube 100 cm² Fast Site Calculation Rules 150 mm cube → Load (kg) ÷ 225 | Load (kN) ÷ 22.5 100 mm cube → Load (kg) ÷ 100 | Load (kN) × 10 12. Sampling Frequency (IS Practice – Simplified) Concrete Quantity No. of Samples Total Cubes 1 – 5 m³ 1 3 6 – 15 m³ 2 6 16 – 30 m³ 3 9 31 – 50 m³ 4 12 Each additional 50 m³ +1 +3 13. Reporting of Results Calculate strength of each cube. Round off to nearest whole number. Average of 3 cubes = representative strength. Variation limits must be satisfied. Concrete Strength Acceptance Criteria (±15% Rule Explained) Basic Rule For any set of 3 cubes (one sample): Calculate average strength Each cube must lie within: 0.85 × Average (−15%) 1.15 × Average (+15%) If even one cube is outside this range, the sample is REJECTED, irrespective of average strength. Key Strength Values – M25 Concrete Characteristic strength (fck) = 25 N/mm² Standard deviation (assumed) = 4 N/mm² Target mean strength = fck + 1.65 × S = 25 + (1.65 × 4) = 31.6 N/mm² CASE–1: Single Sample (Small Quantity Concrete) Concrete Quantity = 5 m³ As per IS practice → 1 sample (3 cubes) Acceptance Criterion (Special Case) When only one sample is available: Average strength ≥ fck + 4 = 29 N/mm² Cube Strengths (N/mm²) Average 0.85 × Avg 1.15 × Avg 19, 26, 16 20.3 17.3 23.3 Reasons for Rejection ❌ Average strength less than 29 N/mm² ❌ Cubes 26 and 16 N/mm² outside ±15% range Final Decision: ❌ CONCRETE REJECTED CASE–2: Multiple Samples (Normal Quantity Concrete) Concrete Quantity = 28 m³ Samples required = 3 samples (9 cubes) Acceptance Criteria Each cube ≥ fck − 2 = 23 N/mm² Overall average ≥ fck + 4 = 29 N/mm² ±15% variation satisfied for each sample Sample-wise Results Sample Cube Strengths (N/mm²) Average 0.85 × Avg 1.15 × Avg 1 33, 29, 32 31.3 26.6 36.0 2 24, 32, 28 28.0 23.8 32.2 3 25, 29, 32 28.7 24.4 33.0 Overall Average Strength (31.3 + 28.0 + 28.7) ÷ 3 = 29.3 N/mm² Acceptance Check (As per IS Acceptance Criteria) ✅ ±15% Variation Check: All individual cube strengths fall within the permissible range of 0.85 × Average to 1.15 × Average for their respective samples. This confirms uniformity in batching, mixing, compaction, and curing of concrete. ✅ Minimum Individual Strength Check: Each tested cube has achieved a compressive strength greater than or equal to fck − 2, i.e. 23 N/mm² for M25 concrete. No cube strength is below the minimum permissible limit. ✅ Average Strength Check: The overall average compressive strength of all samples is 29 N/mm² or higher, which satisfies the requirement of fck + 4 for acceptance of concrete under normal sampling conditions. ✅ Quality and Compliance Confirmation: Since variation, individual strength, and average strength criteria are all satisfied, the concrete meets the

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    Concrete Work

    Profile Corrective Course DBM

    Bituminous Work / /

    Profile Corrective Course (DBM) Construction Methodology | MoRTH Profile Corrective Course (Dense Bituminous Macadam) – Construction Methodology Profile Corrective Course (PCC) using Dense Bituminous Macadam (DBM) is executed to correct pavement profile irregularities such as depressions, sags, uneven camber and surface undulations before laying the final overlay. 1.0 Scope and Surface Preparation The Profile Corrective Course is a bituminous layer of variable thickness (typically 50–100 mm) laid over an existing granular or bituminous surface to restore the correct longitudinal and cross profile as per approved drawings. 1.1 Existing Bituminous Surface Repairs: Potholes, cracks and distressed areas shall be repaired as per MoRTH Clauses 3004.2 & 3004.3. Scarifying: Where specified, existing bituminous layer shall be scarified without disturbing underlying layers. Base Preparation: Exposed surface reworked, compacted and primed if required as per Clause 502. Tack Coat: Bituminous emulsion applied uniformly before laying PCC DBM. 1.2 Existing Granular Surface Surface cleaned of loose material and dust. Priming carried out as per MoRTH Clause 502 before bituminous layer. Surface to be firm, dry and broom-cleaned. 1.3 Pre-Laying Checks Existing top levels shall be jointly checked and recorded before and after preparation to confirm thickness and profile correction. 2.0 Plant, Machinery & Equipment Sl. No. Equipment Quantity 1 Batch Type Hot Mix Plant (200 TPH) 01 2 Sensor Paver with Auto Screed Control 01 3 Pneumatic Tyred Roller 01 4 Tandem Vibratory Roller 02 5 Bitumen Sprayer 01 6 Hydraulic Broom / Air Compressor 01 7 Water Tanker 01 8 Tipping Trucks As required 3.0 Materials & Mix Production 3.1 Materials Coarse & fine aggregates from approved quarries Bitumen: VG-30 / VG-40 (IS:73) Tack Coat: Rapid setting bituminous emulsion 3.2 Job Mix Formula (JMF) JMF shall be prepared in the site laboratory using Marshall Method and approved by IE/PMC. The procedure is identical to DBM/BC mix design as per MoRTH Section 500. 3.3 Hot Mix Plant Operation Bitumen storage temperature: 150–165°C Aggregate drying temperature: 150–170°C Mixing carried out in controlled, dust-free environment Maximum mix temperature not exceeding 165°C 4.0 Laying & Compaction 4.1 Transportation of Mix Mix transported in covered tipping trucks. Truck beds coated with release agent. Mix temperature at dispatch: 155–165°C. 4.2 Tack Coat Application Rate of application: 0.25–0.30 kg/m² Applied by mechanical sprayer DBM laid only after tack coat breaks 4.3 Laying & Finishing Sensor wire fixed at 10 m interval for profile control Minimum laying temperature: 125°C Loose thickness allowance: approx. 25% Manual laying permitted in confined areas 4.4 Compaction Rolling by vibratory roller followed by PTR Rolling from lower edge to higher edge Compaction continued until specified density achieved Joints cut full depth and edges painted with hot bitumen 5.0 Quality Control & Traffic Management Core cutting after 24 hours for density verification Routine bitumen testing for each consignment Surface finish as per MoRTH Clause 902 Traffic opened minimum 24 hours after completion Traffic managed using cones, barricades and flagmen Frequently Asked Questions – PCC DBM What is PCC? A corrective bituminous layer to restore pavement profile. Typical thickness? 50–100 mm per layer. Where used? Depressions, sags, uneven camber. Material used? DBM with VG-30/VG-40 bitumen. Surface preparation? Repair, scarify, clean, prime/tack. Compaction? Vibratory roller + PTR. Joint treatment? Full-depth cut with hot bitumen coating. Traffic opening? After minimum 24 hours. 🏗️ Highway Construction Methodology Hub Standard construction methodologies for highway works as per MoRTH 5th Revision and IRC Specifications. ✅ Earthwork Methodology ✅ Clearing & Grubbing Methodology ➡️ ✅ Embankment Construction Methodology ➡️ ✅ Flyash Embankment Construction Methodology ➡️ ✅ Subgrade Construction Methodology ➡️ ✅ Granular Work Methodology ✅ Granular Sub-Base (GSB) Methodology ➡️ ✅ Wet Mix Macadam (WMM) Methodology ➡️ ✅ Bituminous Work Methodology ✅ Prime Coat Application Methodology ➡️ ✅ Tack Coat Application Methodology ➡️ ✅ Dense Bituminous Macadam (DBM) Methodology ➡️ ✅ Bituminous Concrete (BC) Methodology ➡️ ✅ Profile Corrective Course of DBM ➡️ ✅ Use of Waste Plastic in Bitumen ➡️ ✅ Use of Waste Plastic in Road Construction ➡️ ✅ Thermoplastic Road Marking Methodology ➡️ ✅ Concrete Methodology ✅ Dry Lean Concrete (DLC) Methodology ➡️ ✅ PQC Road Construction Methodology ➡️ ✅ Kerb Construction Methodology ➡️

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    Bituminous Work
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