This Bitumen was developed in the light of the problems experienced by Consultants, Contractors and Architects. There is a general practice to mix Bitumen 80/100 with Bitumen 10/20 on 50:50 or 25:75 basis, however it was noted that if any one asphalt is not available user will either use 10/20 or 80/100.
Moreover, the product after mixing would not be at par to International Standard. Bitumen 10/20 is an ideal product for summer but is highly brittle in winter’s, therefore PB-4 was developed with mixing 80/100 or 10/20 or both at specified ratio with plasticizers added to get high melting point, more flexible and long life. So where temperature fluctuates in summer’s and winter’s this material is highly suitable to use in place of Bitumen 80/100 or 10/20.