Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 2, pp. 309−316.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © S.V. Vorontsov, N.V. Maidanova, A.M. Syroezhko, S.N. Ivanov, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 2,
AND POLYMERIC MATERIALS
Choice of Polymer–Bitumen Binders for Cast Asphalt
S. V. Vorontsov, N. V. Maidanova, A. M. Syroezhko, and S. N. Ivanov
St. Petersburg State Institute of Technology (Technical University), St. Petersburg, Russia
Received March 30, 2011
Abstract—Modiﬁ cation of bitumen with Kraton D1101 and D1192, Luprene LG 411 and 501, and DST-30-01
polymeric additives and the effect of these additives on the properties of cast asphalt concrete mixes were studied.
Various thermoplastics, in particular, styrene–
butadiene–styrene (SBS) block copolymers, are widely
used today beyond Russia for construction and repair
of road pavement. Growing consumption of SBS-type
polymers by the road industry is due to their capability not
only to enhance the bitumen strength, but also to impart
elasticity to the polymer–bitumen compound.
Use of bitumen modiﬁ ed by an SBS-type polymer in
the asphalt concrete mix formulation makes the pavement
capable of rapid relief of stresses arising in the pavement
under the action of trafﬁ c. Today bitumen compounds
with various amounts of SBS-type polymers are widely
used beyond Russia for paving artificial structures
(bridges, overpasses, etc.). The experience shows that
these compounds ensure long service life of pavements,
despite severe conditions of their operation.
Bitumen–polymer compounds are usually prepared
at 150–200°C with vigorous stirring of the components.
Bitumens become soft on heating, and thermoplastic
polymers, irrespective of their being initially crystalline
or amorphous, pass into the viscous-ﬂ ow state .
Mixing of bitumen with polymers of any chemical
nature at high temperature occurs in two steps: emulsiﬁ ca-
tion of the softened polymer in liquid bitumen, followed
by partial (swelling) or complete dissolution. The extent
of polymer dispersion in bitumen, under equal other
conditions, is determined by the chemical nature and
molecular weight of the polymer, chemical composition
of bitumen, and component ratio .
After cooling, the modiﬁ ed bitumens remain homo-
geneous, which is due to a sharp increase in the viscosity
of the prepared polymer–bitumen material on cooling
of the melt, which precludes or complicates the phase
The advantages of cast asphalt concrete (CAC)
compared to compacted asphalt concretes are associated
with speciﬁ c features of the material structure. In the
hardened state, CAC is monolithic in texture. This
fact favors enhancement of the resistance to frost and
aging and of the durability. However, the use of CAC
for paving roads requires special equipment, and the
paving cost is two times higher compared to paving with
common asphalt concrete. At the same time, CAC has
longer service life at any loads; the service life of CAC
pavements is two times longer than that of pavements
made of compacted asphalt concrete (20–30 years). With
the composition chosen properly, CAC pavement does
not deform in summer and does not crack (as a result of
temperature shrinkage) in winter. Furthermore, paving
with CAC does not require compaction with a roller.
In the hot state (~200°С), it is sufﬁ cient only to level
CAC pavement without subsequent rolling. Even at
frosty weather, the material spreads, heating the mineral
base, and ensures good adhesion with it. The CAC
transportation requires special machines with systems
for continuous forced mixing and for maintaining the