Flexible Pavement – Several layers of composition

• Asphalt layer thickness (in inches or mm)

• Layer coefficient for asphalt

• Base layer thickness(in inches or mm)

• Layer coefficient of base

• Sub-base layer thickness(in inches or mm)

• Layer coefficient of sub-base

• Thickness of additional layer(in inches or mm)

• Layer coefficient of additional layer

•  

• Structural Number

  

Formula:

L=a1ta + b1tb + c1tsb +d1tad

Where,

   

   L=Structural Number of Flexible pavement

   a1=Layer coefficient for asphalt

   ta=Asphalt layer thickness

   b1=Layer coefficient of base

   tb=Base layer thickness

   c1=Layer coefficient of sub-base

   tsb=Sub-base layer thickness

   d1=Layer coefficient of additional layer

   tad=Thickness of additional layer

The pavements which flexes and deflects under loading is known as flexible pavement, it is made of several layers of material, use this free engineering calculator to calculate exact measurements of flexible pavements.