Overview Flexible Pavement Design IRC 37 2018 ppt.pptx

Salient features of flexible pavement design

1. 1 NEED OF PAVEMENT DESIGN Determination of thickness of pavement layers based on subgrade , traffic and climatic conditions is known as Pavement Design. Need to decide economic, reliable and suitable thickness of pavement based on traffic and subgrade strength .

2. N f = 1.6064 × C× 10 –4 × (1/ ε t ) 3.89 × (1/ E bit ) 0.854 80% reliability N f = 0.5161 × C× 10 –4 × (1/ ε t ) 3.89 × (1/ E bit ) 0.854 90% reliability Where, N f = No. of cumulative 80 kN-standard axles to cause 20% and more cracked surface area ε t = Tensile strain at bottom fibre of the bituminous layer (×10 –6 ) and E bit = Resilient modulus of the bituminous surfacing (MPa). V be = Volume of effective bitumen binder in the bituminous layer (%) V a = Volume of air voids in the bituminous layer (%) Fatigue Cracking of Asphalt Pavement

3. Subgrade Rutting Criteria N R = 4.1656 × 10 –8 ×(1/ ε z ) 4.5337 80 % reliability < 20msa N R = 1.41 × 10 –8 ×(1/ ε z ) 4.5337 90 % reliability ≥ 20 msa where, N R = No. of cumulative standard axles to produce rut depth of 20 mm ε z = Vertical compressive sub-grade strain (×10 –6 )

4. Fatigue Performance of Cement Treated Base (CTB)

5. Fatigue Performance of Cement Treated Base (CTB) ∑CFD(Single + Tandem + Tridem ) ≤ 1.0? Check : Cumulative Fatigue Damage (CFD) in CTB

6. Standard Conditions for Pavement Analysis using IITPAVE

7. Pavement Composition with Critical Strains

8. Pavement Composition with Critical Strains

9. Pavement Composition with Critical Strains

10. Pavement Composition with Critical Strains

11. Pavement Composition with Critical Strains

12. Pavement Composition with Critical Strains