FLEXIBLE PAVEMENT DESIGN CMND

Properties of Paving Material

 Bituminous Wearing and Binder Courses

DCC30103 Highway & Traffic Engineering (Nizam PMM)

 Bituminous Road base

 similar to binder and wearing course except a lower temperature used for this layer

 Crushed Aggregate and Wet Mix Road Base

 Performance -> shear strength, stiffness and by material breakdown that may occur
during construction and heavy traffic

 similar composition but construction practices are different
 Min CBR 80%, elastic modulus 350±100 Mpa

 Stabilized Road base

 In situ or Plant
 2 types:

 STB 1 . Aggregates stabilised primarily with cement or lime . 3% to 5% Portland
cement.
 E = 1800 MPa; v = 0.40

 STB 2. Aggregates stabilised primarily with a bituminous emulsion/foamed bitumen
+ cementitious. Bituminous emulsion or foamed bitumen and a maximum of 2%
Portland cement.
 E= 1200 MPa; v 0.35

DCC30103 Highway & Traffic Engineering (Nizam PMM)

Other options for Low Volume Roads

DCC30103 Highway & Traffic Engineering (Nizam PMM)

Example:

• Traffic count data: ADT 2700 vehicles both directions (24 hour period)
• PCV: 16% ( no detailed break down by vehicle type)
• Terain : rolling
• Design life: 20 years
• Annual traffic growth: 4%
• CBR mean =18.5% , standard deviation= 4.4%, 85% probability

DCC30103 Highway & Traffic Engineering (Nizam PMM)