Styrene, also known as vinyl benzene and phenyl ethene, is an organic compound with the chemical formula C6H5CH=CH2. This derivative of benzene is a colorless oily liquid that evaporates easily and has a sweet smell, although high concentrations confer a less pleasant odor. Styrene is the precursor to polystyrene and several copolymers. Approximately 25 million tons (55 billion pounds) of styrene was produced in 2010.Acrylonitrile is a chemical compound with the formula C3H3N. This colorless liquid often appears yellow due to impurities. It is an important monomer for the manufacture of useful plastics such as polyacrylonitrile. In terms of its molecular structure, it consists of a vinyl group linked to a nitrile.
The porosity due to air-voids, water voids or due to the inherent porosity of gel
structure itself. On account of the porosity, the strength of concrete is naturally
reduced. It is conceived by many research workers that reduction of porosity results
in increase of strength of concrete.
Therefore, process like vibration, pressure application spinning etc., have been
practiced mainly to reduce porosity.
All these methods have been found to be helpful to a great extent, but none of
these methods could really help to reduce the water voids and the inherent porosity
of gel, which is estimated to be about 28%. The impregnation of monomer and
subsequent polymerization is the latest technique adopted to reduce the inherent
porosity of the concrete,
to improve the strength and other properties of concrete
1. Polymer Impregnated Concrete (PIC).
2. Polymer Cement Concrete (PCC).
3. Polymer Concrete (PC).
Type of Polymer Concrete
Polymer impregnated concrete is one of the widely used
It is nothing but a precast conventional concrete, cured and
dried in oven, or by dielectric heating from which the air in
the open cell is removed by vacuum.
Then a low viscosity monomer is diffused through the open
cell and polymerized by using radiation, application of heat
or by chemical initiation
Polymer Impregnated Concrete (PIC)
Polymer cement concrete is made by mixing cement,
aggregates, water and monomer.
Such plastic mixture is cast in moulds, cured, dried and
polymerized. The monomers that are
used in PCC are:
(d) Vinylidene Chloride.
Polymer Cement Concrete (PCC)
Polymer concrete is an aggregate bound with a polymer binder instead of Portland
cement as in conventional concrete. The main technique in producing PC is to
minimize void volume in the aggregate mass so as to reduce the quantity of polymer
needed for binding the aggregates.
This is achieved by properly grading and mixing the aggregates to attain the
maximum density and minimum void volume.
The graded aggregates are prepacked and vibrated in a moulds. Monomer is then
diffused up through the aggregates and polymerization is initiated by radiation or
A Silone coupling agent is added to the monomer to improve the bond strength
between the polymer and the aggregate. In case polyester resins are used no
polymerization is required.
Polymer Concrete (PC)
PIC has a nearly linear stress-strain relationship to failure. There is very little departure from
linearity up to 90% of ultimate strength and there is no abrupt change at the
proportional limit. The stress strain curves for Styrene-TMPTMA impregnated concrete also show
the same characteristics as for MMA impregnated concrete. The modulus of elasticity increased
from 27 GPa for impregnated specimen to 49 GPa for MMA impregnated specimens.
The effect of polymer loading on the compressive strength in PIC Using methyl methacrylate as
monomer and with a polymer loading of 6.4%, strength of the order of 144 Mpa (thermal
catalytic process was 130 Mpa) have been obtained using radiation technique of polymerization.
The control specimen had compressive strength of 38 MPa
Compressive Strength & Tensile
Polymer impregnated concrete with polymer loading of 5.6% MMA and polymerized by
radiation have shown flexural strength 3.6 times more than that of the control specimen, i.e.
the flexural strength was increased to 18.8 MPa from 5.2 MPa.
Compressive Creep deformation of MMA impregnated concrete and styrene—
impregnated concrete has been observed to be in direction opposite to that of the applied
load i.e., Negative Creep. After the typical initial movement during load application, these
concretes expand under sustained compression
Flexural Strength & Creep
Freeze Thaw Resistance
Polymer impregnated concrete has shown excellent resistance to freeze-thaw MMA impregnated
and radiation polymerized specimens have withstood 8110 cycles of freeze-thaw compared to
740 cycles in case of unimpregnated concrete. Even partially impregnated concrete withstood
Resistance to Sulphate Attack
it has been observed that there is at least 200% improvement in the resistance of polymer
impregnated concrete and 89% improvement in the case of partially impregnated concrete
over the conventional concrete.
The acid resistance of PIC has been observed to improve by 1200% when exposed to 15% HCI
for 1395 days.
A maximum reduction of 95% in water absorption has been observed with
concrete containing 5.9% polymer loading