Tire Pressure (psi) and Thickness (mm) Design of Asphalt Pavement Layers, are the Key...
A great Chef (Pavement cum Materials Engineer) knows, what is the Taste requirements of Clients (Tire and Asphalt interface in Airport/ Highways) and Cooking perfectly in the Kitchen (or Hot Mix Plant) is All about.
If the Chef cooks well the Food (Asphalt Mix to suit Tire Pressure/ Layer Thickness), it will meet the requirements for a performing Clients (Asphalt Pavement) for Entire (Design) Life.
It is not Necessary and not Needed to use Modified Bitumen (MB), considering the Environmental and Loading conditions for a performing pavement.
Why use PG grade bitumen (or any modified binder) in "Superpave method of mix design" for Airport pavements, rather We should use 60/70 viscosity grade.... and Reduce Capital Cost...
-What's (or Nothing) Wrong!
In Airfields, Superpave method of Mix design has not been verified for its applicability across the globe.Often, We wrongly/ blindly compare and apply Superpave technology in Asphalt mix design.
Our experience suggests, it is not mandatory to use Modified Bitumen in Asphalt layers in Airport pavement, if you diligently design the "Normal Asphalt Mix Design Specifications" and pavement layers’ thicknesses (mm) as per the anticipated Tire pressure (psi).
I'm busy working on my blog posts. Watch this space!