• Survey and Marking:
  • - Establish road alignment, levels, and cross-section as per drawings
  • - Mark center line, edges, and cross-section details
  • - Verify horizontal and vertical curves for proper drainage
• Subgrade Preparation:
  • - Excavate to desired depth (typically 300-450mm below finished road level)
  • - Remove all organic material, debris, and unsuitable soil
  • - Compact the subgrade to minimum 97% of Modified Proctor Density (MDD)
  • - Check soil strength with CBR test (minimum 5% for subgrade)
  • - Ensure proper camber (cross-slope: 2-2.5%) for drainage
• Granular Sub-base (GSB):
  • - Place GSB material in layers not exceeding 150mm thickness
  • - Ensure proper moisture content for optimum compaction
  • - Compact using rollers to achieve minimum 98% MDD
  • - Verify levels, camber and compaction at regular intervals
• Wet Mix Macadam (WMM):
  • - Place WMM layer over GSB with correct moisture content
  • - Spread evenly maintaining required thickness (100-250mm)
  • - Compact thoroughly using vibratory rollers
  • - Test compaction density (minimum 98% MDD)
  • - Check surface regularity with 3m straight edge

• Surface Preparation:
  • - Clean WMM surface thoroughly, removing all dust and loose material
  • - Ensure surface is dry but slightly damp (not wet)
  • - Repair any damages or irregularities in the surface
  • - Check levels and camber before prime coat application
• Prime Coat Material:
  • - Use Medium Curing (MC-30) or Slow Setting (SS-1) bitumen emulsion as per IS 8887:2004
  • - Heat prime coat material to proper temperature (50-70°C)
  • - Test viscosity to ensure proper flow characteristics
• Application Method:
  • - Use mechanical sprayer for uniform application
  • - Apply at rate of 0.7-1.0 kg/m² depending on surface porosity
  • - Ensure complete and uniform coverage without pooling
  • - Allow 24-48 hours curing time (no traffic during this period)
  • - Check penetration depth before proceeding to next step

• Surface Preparation:
  • - Clean primed surface thoroughly before tack coat application
  • - Remove any foreign matter or contaminants
  • - Repair any damaged areas in the prime coat
• Tack Coat Material:
  • - Use Rapid Setting (RS-1) or (RS-2) bitumen emulsion as per IS 8887:2004
  • - Heat to appropriate temperature (50-70°C)
  • - Test for proper viscosity and adhesion properties
• Application Process:
  • - Apply using mechanical pressure sprayer for uniform distribution
  • - Application rate: 0.2-0.4 kg/m² (thin, uniform layer)
  • - Prevent overspray on curbs, structures, or adjacent surfaces
  • - Allow proper breaking time (brownish color indicates readiness)
  • - Verify adhesion characteristics before bituminous mix laying

• Aggregate Preparation:
  • - Test aggregates for gradation, shape, strength as per IS 2386
  • - Ensure proper stockpiling to prevent contamination
  • - Heat aggregates to temperature range of 150-170°C
  • - Verify moisture content (should be minimal)
• Bitumen Preparation:
  • - Use specified grade (VG-30/VG-40) as per IS 73:2013
  • - Heat bitumen to 150-165°C (never exceed 177°C)
  • - Check temperature regularly to prevent overheating
  • - Test penetration value and viscosity before mixing
• Mix Production:
  • - Follow job mix formula for proportioning aggregates and bitumen
  • - Typical bitumen content: 5.0-5.5% by weight of mix
  • - Mix thoroughly in hot mix plant (batch or continuous type)
  • - Maintain mixing temperature between 150-165°C
  • - Test mix for stability, flow, voids, and density as per Marshall method
• Transportation:
  • - Use trucks with clean, smooth beds coated with anti-sticking agent
  • - Cover loads with tarpaulin to maintain temperature and prevent contamination
  • - Transport quickly to minimize temperature loss
  • - Monitor mix temperature upon arrival (minimum 130°C)

• Paver Setup:
  • - Set up sensor paver with correct width and thickness controls
  • - Adjust screed for proper level, camber, and crown
  • - Verify paver speed for optimal laying operation
  • - Check automatic grade and slope controls
• Laying Process:
  • - Transfer mix from truck to paver hopper carefully
  • - Maintain consistent paving speed (2-4 m/min)
  • - Ensure uniform thickness as per design (40-75mm typical)
  • - Monitor temperature during laying (130-150°C)
  • - Check layer thickness and cross slope at regular intervals
• Joint Construction:
  • - Create proper longitudinal and transverse joints
  • - Ensure joints are straight and properly overlapped
  • - Apply tack coat to joint edges when necessary
  • - Properly compact joints to prevent water infiltration
• Compaction Sequence:
  • - Begin initial rolling immediately (mix temp: 120-135°C)
  • - Use 8-10 ton tandem rollers for initial compaction
  • - Follow with pneumatic-tired roller for intermediate rolling
  • - Finish with tandem roller for final surface texture
  • - Compaction pattern: start from edge toward center, overlap 15-30cm
  • - Complete 8-12 passes to achieve required density (97-98% of lab density)
• Field Testing:
  • - Check density using core cutter or nuclear density gauge
  • - Test surface evenness with 3m straight edge (max deviation 4mm)
  • - Verify proper cross slope and superelevation
  • - Check thickness through test cores at specified intervals

Problem: Excess bitumen rises to surface creating shiny, slick patches.

Solution: Reduce bitumen content in mix design, ensure proper mix temperature, apply sand blotter in severe cases, check compatibility between bitumen grade and traffic load.

Problem: Surface aggregates dislodge from pavement.

Solution: Ensure proper bitumen content, check aggregate quality and cleanliness, improve compaction techniques, verify mix is not being laid at too low temperature.

Problem: Longitudinal depression in wheel paths.

Solution: Improve subgrade/base layer stability, use stiffer bitumen grade, adjust aggregate gradation, increase field compaction, review mix design for proper voids in mineral aggregate (VMA).

Problem: Separation of coarse and fine materials during placement.

Solution: Improve handling during loading/unloading, maintain proper paver hopper level, reduce drop heights, avoid stopping paver during operations, check for proper mix temperature.