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Performance Evaluation Report on Rural Roads Constructed Using CRRI-Bitchem Cold Mix in Different District of Assam during 2008-2009

The hot bitumen and emulsifier solution are fed in separately but simultaneously into the colloid mill. The
temperature of the two components vary, depending on the grade and percentage of bitumen in the emulsion, the
type of emulsifier used. The viscosity of the bitumen entering the colloid mill should not exceed 0.2 Pa.s(2 poise).
To achieve viscosity of the bitumen, temperatures in the range of 100ºC to 140ºC are used. The temperature of the
water phase is adjusted so that the temperature of the produced is not greater than 90 ºC. The individual globules
are then coated with the emulsifier which gives the surface of the droplets an electrical charge and the resulting
electrostatic forces prevent the globules from coalescing.

1.4 Classification of Bitumen Emulsion

Bitumen emulsions are classified into Anionic, Cationic and Non-ionic type. Each type if further divided into
Rapid setting (RS), Medium setting (MS) and Slow Setting (SS) grade depending upon the breaking time of
emulsion. Rapid setting grade of emulsion has less breaking time while medium and slow setting emulsions are
having more breaking time thus allowing mixing with coarse aggregate and fine aggregate. The recommended
uses of this grade of emulsions are given below:

Type Recommended uses
Rapid Setting (RS) : A quick setting emulsion used for surface treatment. Surface Dressing,
Penetration macadam and tack coating.
Medium Setting (MS): A medium setting emulsion used for plant or road mixes with course aggregate for
premix carpet, surface dressing and tack coating.
Slow Setting (SS) : A slow setting emulsion used for plant or road mixes with graded of fine
aggregate. This emulsion is also used for slurry treatment dense asphalt concrete
and tack coating.

1.5 CRRI-BitChmem Cold Mix Binder & Cold Mix Technology -

CRRI-BitChem Cold mix Binder is a mix design tailor made bitumen emulsion with certain performance
additives like anti-stripping agent and medium and slow characteristics used as a binder in cold mix technology in
various applications of road construction. The main feature of this cold mix binder is that this binder has been
customized to use with the aggregates available from any source in India i.e. dusty Aggregates, soil coated
Aggregates, clean Aggregates, damp Aggregates , pea gravel Aggregates or the Cal Carious (lime mix)
Aggregates.

These binder exceed IS 8887:2004 specification of SS-2 to provide durable roads.
Different types of CRRI-BitChem Cold Mix Binder are as follows -

QSP/MR/19/ ACED/BTCM/214/2013 CSIR-NEIST/CNP-462