Polymer Modified Bitumen

Modified bituminous materials can bring real benefits to highway maintenance/construction, in terms of better and longer lasting roads, and savings in total road life costing.

But the choice of what materials to choose and how they perform has to be said is a bit of a minefield at present with little truly independent advice available, and this guide may help in making the necessary decisions.

This guide is an attempt to provide some fairly practical information on modified bituminous materials, particularly materials where the bitumen have been modified by the addition of a polymer.

There are some of the problems that can be encountered in the storage of modified binders, the production of bituminous material, and the storage of mixed material prior to laying.

Where to use:

• Runways, Taxiways and Aprons at airports.
• Highways, Expressways & Bridges.
• Busy intersection, round-about, slopes.
• Heavy vehicle & multimodal parking lots.
• Anywhere, where conventional pavement materials fail.

Advantages:

• Highly cohesive durable surfaces.
• Excellent anti stripping properties and resistance to fatigue.
• Cost effective overlay thickness.
• Reduced maintenance & life-cycle costs.
• Resistance to fuel spillage deterioration.    

Types of PMB

• PMB 120: Recommended for cold climate areas
• PMB 70: Recommended for moderate climate areas
• PMB 40: Recommended for hot climate areas 

We have in store for our clients, Cut-Back Bitumen, which is developed as per the IS standards. Clients can avail cut-back bitumen of RC-3, MC-3, and MC-5 grades for cold weather construction and maintenance under all weather conditions. It is a free flowing liquid at normal temperatures. The cut-back bitumen we are offering is obtained by fluxing bitumen with suitable solvents. Its viscosity is substantially reduced by adding Kerosene or any other solvent. Further, Cut-back is used in tack coat applications and its various grades are available in India, which are governed by IS: 217:1988 standards.

Types and grades:

Cut-back Bitumen shall be of three types:

• Rapid Curing (RC)
• Medium Curing (MC)
• Slow Curing (SC)

Tests for Cut-Back Bitumen:

Viscosity:

• A standard test as specified in IS:1206-1978 Part-I
• For Cut-Back Bitumen, a standard tar viscometer (STV ) of 4 mm diameter orifice is used
• The grade of Cut-back bitumen is designated by its viscosity value

Flash Point:

• This standard test is specified in IS : 1209-1978
• For Cut-Back Bitumen, flash Point in ° C is determined by Pensky Martens closed cup apparatus
• The value signifies the safe temperature to which cut-back bitumen can be heated

Distillation:

• A standard test specified in IS:1213-1978
• In this test volatile constituents Cut back bitumen are separated between different specified temperature ranges
• From this, the type of cut back bitumen can be identified
• The type and quantity of distillate controls the curing time of cut back bitumen
• Cut back bitumen RC-3 is obtained by blending paving bitumen 80/100 with about 16 percent by weight of naphtha type distillate requires approximately 12 hours of curing time
• A cut back bitumen is taken as cured when the float value at 50° C is more than 120 seconds
• The details of float test are given in IS: 1210-1978
• Residue obtained from the distillation test is tested for penetration and ductility to determine the nature of base bitumen used in preparation of cut-back bitumen