Kishor Kumar

    tackcoat spraying

    Tack Coat in Road Construction | Methodology & IRC Guide

    Bituminous Work / /

    Tack Coat Methodology as per MoRTH Clause 503 | Highway Quality Test Tack Coat Methodology (MoRTH Clause 503) Author: Kishor Kumar | Category: Bituminous Works | Specification: MoRTH Clause 503 Quick Overview: Tack Coat is a thin application of rapid-setting cationic bitumen emulsion applied over a primed granular layer or existing bituminous surface to ensure proper bonding between pavement layers. Why Tack Coat Is Critical in Pavement Performance Improper tack coat application is one of the most common causes of pavement layer slippage, delamination, and premature cracking. Tack coat ensures shear resistance and structural continuity between successive bituminous layers. Quick Technical Reference Applicable Clause: MoRTH 503 (5th Revision) Material: RS-1 / RS-2 Cationic Bitumen Emulsion Application Rate: 0.20–0.30 kg/m² Surface Condition: Dry, clean, dust-free Traffic Allowance: Only after emulsion breaks Applicable Codes & Specifications MoRTH Specifications – Clause 503 IRC: SP: 84 – Manual of Specifications & Standards IS: 8887 – Bitumen Emulsion for Roads IS: 1203 – Penetration Test (Bituminous Materials) Materials Requirements Material Requirement Bitumen Emulsion RS-1 / RS-2 Cationic, IS:8887 compliant Water Not permitted for dilution unless approved Equipment Required Calibrated bitumen pressure distributor Mechanical broom / air compressor Tray for spray rate check Thermometer and spray bar adjustment system Tack Coat Application Methodology – Step by Step Verify underlying surface condition Remove dust and loose particles Check weather (no rain, dry surface) Calibrate pressure distributor Spray tack coat uniformly at approved rate Avoid streaking and overlapping Allow emulsion to break Proceed with next bituminous layer Application Rates (Acceptance Criteria) Surface Type Application Rate Existing Bituminous Surface 0.20 – 0.25 kg/m² Primed Granular Surface 0.25 – 0.30 kg/m² Curing & Traffic Control Tack coat must be allowed to break (brown to black appearance). No traffic or construction equipment shall be permitted until the surface becomes tacky and non-tracking. Quality Control Checkpoints Layer Inspection Stage Test / Parameter Standard Frequency Acceptance Criteria Tack Coat Inspection at Source Quality of Binder IS: 1201 to IS: 1220 1 Sample / Lot Bitumen Emulsion complying with IS:8887 & Cutback Bitumen complying with IS:217 In-process / Final Inspection Binder Temperature IRC:16 At regular close intervals 20°C – 70°C for Bitumen Emulsion 50°C – 80°C for Cutback Bitumen Rate of Spread of Binder IRC:16 Minimum Three Tests per Day Granular surface treated with primer: 2.5 to 3.0 Kg/10 m² Bituminous Surface: 2.0 to 3.0 Kg/10 m² Common Field Problems & Remedies Streaking: Poor nozzle calibration → clean & adjust spray bar Excess tack: Over-application → recalibrate distributor Peeling layers: Insufficient tack or dusty surface Tracking: Traffic allowed before breaking Safety & Best Practices Use PPE during spraying operations Ensure barricading and traffic diversion Avoid tack coat during rain or fog Maintain daily spray records Frequently Asked Questions (FAQ) What is the purpose of tack coat? To ensure proper bonding between existing and new bituminous layers. Can tack coat be applied on wet surface? No. Surface must be dry and clean. Which emulsion is used for tack coat? Rapid-setting cationic emulsion RS-1 or RS-2 as per IS:8887. How long should tack coat cure? Typically 20–30 minutes until emulsion breaks. Prepared by Highway Quality Engineers | Educational & Site-Reference Content 🏗️ 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
    prime coat spraying

    Prime Coat in Road Construction (Application Method & Guidelines)

    Bituminous Work / /

    Top 8 Proven Steps for Prime Coat over WMM | MoRTH Clause 502 Top 8 Proven Steps for Prime Coat over Wet Mix Macadam (WMM) Quick Summary: Prime Coat is a low-viscosity bituminous emulsion applied over WMM to seal pores and ensure strong bonding with the next bituminous layer. As per MoRTH Clause 502, the standard application rate is 0.7–1.0 kg/m². 1. Scope of Prime Coat Prime Coat is applied over a prepared Wet Mix Macadam (WMM) base prior to laying Tack Coat and Dense Bituminous Macadam (DBM). It stabilizes the base and prevents absorption of binder from upper layers. 2. Reference Standards MoRTH Specifications – Clause 502 (5th Revision) IRC: SP: 84 – Manual of Specifications IS: 8887 – Bitumen Emulsion 3. Materials Used Cationic bitumen emulsion SS-1 or MS-1 conforming to IS:8887, approved by the Engineer with valid test certificates. 4. Equipment Required Self-propelled bitumen pressure distributor Mechanical broom or power sweeper Air compressor for dust removal Thermometer and spray gauge 5. Surface Preparation The WMM surface must be clean, dry, and free from loose particles. Light water sprinkling may be done if dusty, followed by adequate drying. 6. Application Procedure Ensure emulsion temperature as recommended. Calibrate the distributor for correct spray rate. Apply Prime Coat uniformly at 0.7–1.0 kg/m². Avoid pooling, streaking, or overlapping. 7. Curing & Traffic Restriction Allow the primed surface to cure for a minimum of 24 hours. No traffic or construction equipment shall be allowed during curing. 8. Quality Control & Inspection Layer Inspection Stage Test / Parameter Standard Frequency Acceptance Criteria Prime Coat Inspection at Source Quality of Binder IS: 1201 to IS: 1220 1 Sample / Lot Bitumen Emulsion complying with IS:8887 & Cutback Bitumen complying with IS:217 In-process / Final Inspection Binder Temperature IRC:16 At regular close intervals 20°C – 70°C for Bitumen Emulsion 50°C – 80°C for Cutback Bitumen Rate of Spread of Binder IRC:16 Minimum Three Tests per Day As per Table No. 300-3 & 500-4 of MoRTH 5th Revision Quick Reference – Prime Coat Clause: MoRTH 502 Material: SS-1 / MS-1 Bitumen Emulsion Rate: 0.7–1.0 kg/m² Surface: Clean, dry WMM Curing: Minimum 24 hours FAQs – Prime Coat over WMM Why is Prime Coat required? It seals WMM pores and improves bonding with bituminous layers. Can Prime Coat be applied on wet surface? No, surface must be completely dry. Is traffic allowed after priming? No traffic until full curing. What comes after Prime Coat? Tack Coat as per MoRTH Clause 503. After Prime Coat curing, proceed with Tack Coat Application followed by DBM Construction. 🏗️ 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

    Embankment Construction Methodology | Highway Earthwork Guide

    Earthwork / /

    Embankment Construction Methodology with Quality Control | MoRTH Clause 305 Embankment Construction Methodology with Quality Control – MoRTH Clause 305 Scope of Work The work shall consist of construction of embankment with approved and specified materials obtained from approved borrow areas or suitable material obtained from roadway excavation and drain excavation and in accordance with clause 305 of MORTH specifications. Reference Standards MoRTH Specifications – Section 305 (5th Revision) IRC SP: 84 IS 2720 Series – Soil Testing Approved Project Drawings Manpower & Responsibilities Manpower & Responsibilities Construction Manager Engineer / Supervisor Land Surveyor Material Engineer Safety Supervisor Helpers Construction Manager He shall be overall responsible for the activity including: Planning and organizing resources required for execution in consultation with the Project Manager. Implementation of safety requirements during the work including utility services protection. Ensuring all relevant tests are conducted as per specification. Maintaining all QA/QC records as per contract requirements. Coordinating with the consultant engineer for obtaining necessary approvals for completed activities. Engineer / Supervisor Responsibilities include: Deployment of required resources at site as per planning. Execution of work as per approved drawings. Maintaining quality control as per specifications. Implementation of safety regulations at site. Obtaining approvals for completed works from consultant/authority. Land Surveyor Responsibilities include: Establishing reference points for alignment and levels. Ensuring correct setting out of works. Checking and recording levels of completed work. Coordinating with consultant staff for final approval of finished works. Material Engineer Responsibilities include: Implementation of quality procedures as per approved plan. Ensuring all materials meet specification requirements. Conducting required laboratory and field tests as per standards. Maintaining complete material testing records and reports. Safety Supervisor Responsibilities include: Ensuring safe execution of all site activities. Implementation of project safety plan and guidelines. Monitoring compliance of safety measures at site. Setting Out After completion of site clearance, the limits of embankment shall be marked by fixing pegs on both sides at regular intervals. The chainage boards and working bench mark shall be set outside the limits of construction areas. Material Selection & Borrow Area Testing Selection of Material and Borrow Areas Material The material used in embankment shall be soil, moorum, gravel, reclaimed material from pavement, fly ash, pond ash, a mixture of these or any other material approved by the AE. It shall be free of logs, stumps, roots, rubbish and any other material likely to deteriorate or affect the stability of the embankment. The material for embankment shall be obtained from the approved source with preference to the material becoming available from nearby roadway excavation or any other excavation under the contract. The material requirements shall be in accordance with Clause 305.2 of MORTH specifications. These materials shall be free from logs, stumps, roots, rubbish or any other ingredients likely to affect the stability of the embankment. The material that has LL less than 55%, PI less than 25%, and Free Swell Index less than 50% shall be used for embankment construction. The material which is having lab MDD 15.2 minimum as per IS: 2720 Part-8 shall be used in embankment filling. The sample from the borrow area shall be brought to the laboratory and tested for the above requirements. Clods and hard humps of earth will be broken to a maximum size of 75 mm for embankment. If the moisture content (NMC) is less than OMC, the water shall be added by sprinkling considering evaporation losses, so that at the time of compaction it is in the range of 1% above to 2% below the optimum moisture content. If NMC is more than OMC, the material can be allowed to dry by exposure to the sun. EMBANKMENT/STRUCTURE BACK FILLS The following type of material shall be considered un-suitable. Material from swamps, marshes and bogs. Peat, log, stump and perishable material. Soil classified as OL, OI, OH or Pt. in accordance with IS: 1498. Material susceptible to spontaneous combustion. Material in frozen condition. Clay having LL exceeding 70 and PI exceeding 45 for Embankment. Clay having LL exceeding 50 and PI exceeding 25 for Subgrade. Material with salts resulting in leaching in the embankment. Soils having free swelling index more than 50% shall not be used as filled material. Soil having acceptedbelow free swelling index (non-expensive soils) shall be used up to 500 mm below sub-grade/embankment top. Fill material having soluble Sulfate content exceeding 1.9 gm. of Sulfate per liter (As per BS: 1377 test 10) not to be deposited with 500 mm in contact with concrete structure or cement bound materials forming part of permanent work. Fill material having total Sulfate content exceeding 0.5% by mass. (Tested as per BS: 1377 test 9) shall not be deposited with 500 mm of metallic item forming part of Permanent Work. The maximum size of coarse material in earth mixture shall not exceed 75 mm for embankment fill and 50 mm for sub grade fill. Soil material shall satisfy density requirement as given in BELOW Density Requirements for Embankment & Subgrade Material Sl. No Type of Work Maximum Laboratory dry unit weight when tested as per IS: 2720 (Part 8) 1 Embankments up to 3.0 m high not subjected to extensive flooding. Not less than 15.2 KN/cum or 1.55 gm /cc. 2 Embankment exceeding 3.0 m ht. or Embankment of any height subject to long period of inundation. Not less than 16.0 KN/cum 1.631 gm/cc. or 1.6 gm/cc 3 Sub grade and earthen shoulder / backfill Not less than 17.5 KN/cum or 1.784 gm/cc Note: Materials used shall satisfy design CBR i.e. soaked CBR shall not be less than 12% and 10% as per design locations for Heavy weight fill material. This below is not applicable for light weight fill material. Compaction Requirement The Embankment /sub grade material shall be compacted in one or more layer as per contract. The compacted field density shall meet minimum density requirement as given in BELOW Compaction Requirements for Embankment & Sub grade Sl. No Type of work/material Relative Compaction % of max. Laboratories dry density as

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    Earthwork
    Los Angeles Abrasion Test Apparatus

    Los Angeles Abrasion Test IS 2386 Part IV

    Aggregate / /

    Los Angeles Abrasion Test – Procedure, Calculation, Apparatus & Limits (IS 2386 Part IV) The Los Angeles Abrasion Test is one of the most important tests used to evaluate the toughness and abrasion resistance of coarse aggregates used in road construction and concrete works. This test determines how aggregates behave when subjected to wear, impact and grinding action. Aggregates with high abrasion resistance ensure longer pavement life, better durability and reduced maintenance costs. The test is conducted according to IS 2386 (Part IV) – Methods of Test for Aggregates and is also specified in MoRTH Specifications for Road and Bridge Works (5th Revision, 2013). Importance of Los Angeles Abrasion Test in Highway Engineering Aggregates are the primary load-bearing material in flexible pavements. When traffic loads move over pavement surfaces, aggregates are continuously subjected to: Abrasion due to tyre friction Impact from moving vehicles Grinding action between aggregate particles If aggregates are weak, they will break into smaller particles, causing: Pavement rutting Loss of surface texture Premature road failure The Los Angeles Abrasion Test helps engineers select durable aggregates suitable for highway construction. Objective of the Test The main objectives of the Los Angeles Abrasion Test are: To determine the abrasion resistance of aggregates To measure the toughness of aggregates To evaluate the quality of aggregates for road works To ensure aggregates meet MoRTH specifications Relevant Standards IS 2386 (Part IV) – 1963 Methods of test for aggregates for concrete. MoRTH Specifications (2013) Specifications for road and bridge works. ASTM C131 / ASTM C535 International standards for abrasion testing. Apparatus Required for Los Angeles Abrasion Test Los Angeles Abrasion Machine Hollow steel drum Internal diameter: 700 mm Length: 500 mm Rotational speed: 30–33 rpm Steel Abrasive Balls Diameter: 48 ± 2 mm Weight: 390 – 445 g each Hardness: 400 – 450 HB IS Standard Sieves Weighing Balance (accuracy 1 g) Drying Oven (105 – 110°C) Tray and sieve brush Sample Preparation Proper sample preparation is essential for accurate test results. The following steps should be followed: Collect representative aggregate samples. Wash aggregates to remove dust and impurities. Dry the aggregates in an oven at 105–110°C. Allow the sample to cool to room temperature. Weigh the required sample weight (usually 5000 g). Grading of Aggregates for the Test Grading Aggregate Size (mm) Sample Weight (g) No. of Revolutions Typical Use A 63 – 50 5000 500 Granular Sub Base B 50 – 40 5000 500 WMM Base C 40 – 25 5000 500 Dense Bituminous Macadam D 25 – 20 5000 500 Bituminous Macadam E 20 – 12.5 5000 1000 Bituminous Concrete Test Procedure PROCEDURE – LOS ANGELES ABRASION TEST Clean aggregates dried in an oven at 105–110°C shall be used for testing. The grading used in the test should be nearest to the grading to be used in the construction. Aggregates weighing 5 kg for grading A, B, C or D and 10 kg for grading E, F or G may be taken as test specimen and placed in the cylinder. Choose the abrasion charge depending on the grading of the aggregate and place in the cylinder of the machine. Fix the cover dust tight and rotate the machine at a speed of 30 to 33 revolutions per minute. The machine shall be rotated for 500 revolutions for grading A, B, C and D, and for grading E, F and G it shall be rotated for 1000 revolutions. After the desired number of revolutions, stop the machine and discharge the material from the machine taking care to take out entire stone dust. Using a sieve of size 1.70 mm IS Sieve, the material is first separated into two parts and the finer portion is taken out and sieved further on a 1.70 mm IS Sieve. The portion of material coarser than 1.70 mm size is washed and dried in an oven at 105–110°C to constant weight and weighed correct to one gram. Calculation of Los Angeles Abrasion Value The Los Angeles abrasion value is calculated using the following formula: Los Angeles Abrasion Value (%) = ((A − B) / A) × 100 Where: A = Original weight of sample (g) B = Weight retained on 1.70 mm sieve after test (g) Example Calculation Initial weight of sample = 5000 g Weight retained after test = 3600 g Abrasion Value = ((5000 − 3600) / 5000) × 100 Abrasion Value = 28% Permissible Limits as per MoRTH Layer Maximum LA Abrasion Value Granular Sub Base 45% Base Course 40% Bituminous Layers 35% Wearing Course 30% Advantages of the Test Simple and widely used method Provides reliable measure of aggregate toughness Essential for pavement design Helps maintain highway quality control Limitations of the Test Does not fully simulate field traffic conditions Results may vary for soft aggregates Not suitable for very small aggregates Frequently Asked Questions (FAQ) What is the Los Angeles Abrasion Test? It is a laboratory test used to determine the resistance of aggregates to abrasion and impact. What is the maximum permissible abrasion value? For wearing courses in highways, the maximum value is typically 30%. Which IS code specifies the test? The test is specified in IS 2386 (Part IV). What does a lower abrasion value indicate? Lower abrasion value means stronger and more durable aggregates. Related Aggregate Tests for Highway & Concrete Works Explore detailed test procedures, calculations and acceptance criteria as per IS, MoRTH & IRC specifications: ✅ Aggregate Impact Value (AIV) Test – Toughness of Aggregates ✅ Los Angeles Abrasion Test – Wear & Abrasion Resistance ✅ Aggregate Crushing Value (ACV) Test – Strength Evaluation ✅ Flakiness & Elongation Index Test – Shape Characteristics ✅ Water Absorption Test – Durability & Porosity Check 📌 Pro Tip: Use AIV, ACV, Los Angeles Abrasion, and Shape & Water Absorption Tests together to ensure aggregate suitability for bituminous layers & cement concrete as per MoRTH Section 400 & 500.

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