Polymer Concrete

And

Polymer Fiber Reinforced

Concrete

Prepared By

Mohammed Abdul Haakim

M.E. Structural Engineering

IST

Year-IST

Semester

M.J.C.E.T

INTRODUCTION Concrete is a composite material containing cement, water, coarse aggregate and fine aggregate.

The resulting material is a stone like structure which is formed by the chemical reaction of the cement

and water.

Some of the reasons for this are its simplicity in preparation, the easy availability and low cost of its

ingredients, and above all, the satisfactory properties of the structure.

Concrete strength is much influenced by the porosity of hardened concrete.

When the water dries out it leaves pores .These pores become the entry points for liquid water, water

vapor, different gases and chemical substances that could be damaging to concrete.

Any reduction of the concrete porosity adds to its strength.

To improve the strength of concrete, its susceptibility to corrosion, to make it more durable, and

withstand any kind of abrasion resistance, reduce its porosity , reduce the values of heat of hydration

,to have more tensile strength and to be more ductile a concrete which almost or nearly eradicates the

above drawbacks was developed known as polymer concrete.

Polymer concrete is a part of group of concretes that use polymers to supplement or replace cement as

a binder

Polymer concretes are relatively high-performance materials that have been developed since the early

1960’s.

Polymer concrete consists of well-graded aggregates bonded together by a strong resin binder instead

or along with water and cement, which are alone typically used in cement-based materials.

Polymer concretes are very strong, anticipated to be durable, and cures very rapidly, which is an

important consideration in many civil engineering applications.

This stone like material is a brittle material which is strong in compression but very weak in tension

due to which cracks develop and concrete fails.

So to increase the tensile strength of concrete a technique of introduction of fibers reinforced in

polymer concrete is being used. These fibers act as crack arrestors and prevent the propagation of the

cracks. These fibers are uniformly distributed and randomly arranged. This concrete is named as fiber

reinforced polymer concrete.

The production of Portland cement as a major construction material worldwide releases large amounts

of CO2 in to the atmosphere (production of 1 tone OPC releases 1 tone CO2), and this gas is a major

contributor to the greenhouse effect and the global warming of planet

The main benefit of geopolymeric cement/concrete is reduction in environmental impacts to move

toward sustainable development which is defined as the optimum usage with correct and efficient

operation of basic and natural resources for providing the requirements of the future generation.

Therefore, the availability and application of polymer concrete in local construction is worth to

explore.

POLYMER CONCRETE

Polymer concrete is a part of group of concretes that use polymers to supplement or replace cement as a binder

The composites using polymer can be:

1. Polymer concrete (PC), when the binder is a polymer that replaces the cement paste

2. Polymer modified concrete (PMC), when the polymer is mixed along with cement

3. Polymer impregnated concrete (PIC), when the cement concrete is treated by soaking and

polymerization.

4. Partially Impregnated And Surface coated polymer concrete

1.POLYMER CONCRETE

Polymer concrete is a composite material which results from polymerization of a monomer/aggregate

mixture. The polymerized monomer acts as binder for the aggregates and the resulting composite is

called “Polymer Concrete.”

PREPARATION

The main technique in producing PC is to minimize the volume of voids in aggregate so as to reduce

the quantity of polymer required for binding the aggregates. This is achieved by properly grading the

aggregates so as to attain maximum density and less voids

T=these aggregates are prepacked and vibrated well in a mould and monomer is diffused through the

aggregates and polymerization is initiated.

A silane coupling agent is added to the monomer to improve the bond strength between the aggregates

and the polymer

Polymer concrete is similar to ordinary cement concrete because it contains fine and coarse aggregates,

but the hydraulic binder is totally substituted with a polymer material.

The aggregates are bounded together by the polymer matrix.

Polymer concrete contains no cement or water.

The performances of polymeric concrete depend on the polymer properties, type of filler and

aggregates, reinforcing Fiber type, curing temperature, components dosage, etc.,

The aggregate must be of good quality, free of dust and other debris, and dry.

Failure to fulfill these criteria can reduce the bond strength between the polymer binder and the

aggregate.

The resin dosage reported by various authors mostly lie in the range of 10 to 20% by weight of polymer

concrete. Early studies on polyester resin concrete while taking resin content as a variable reported that

compressive strength of polymer concrete is dependent upon the resin content

Normally, the binder content ranges from 5% to 15% of the total weight but if the aggregate mix is

fine, it may even require up to 20% binder

Normally aggregates are added in two size groups, that is, coarse aggregates comprising material of

more than 5 mm size and fine aggregates having size less than 5 mm

Polymer binder can be a thermoplastic, but more frequently a thermosetting Polymer.

Thermosetting Polymer

A thermosetting plastic, also known as a thermoset, is a petrochemical material.

They are induced by heat, generally above 200 °C (392 °F), through a chemical reaction, or

suitable irradiation

Thermoset materials are usually liquid or malleable prior to curing and designed to be molded into their

final form.

Once hardened a thermoset resin cannot be reheated and melted to be shaped differently.

Eg: Vulcanized rubber,Epoxy resins

Thermoset materials are generally stronger than thermoplastic materials and are also better suited to

high-temperature applications.

Since their shape is permanent, they tend not to be recyclable as a source for newly made plastic.

Thermo plastic polymer

A thermoplastic, or thermosoftening plastic, is a plastic material, typically a polymer, that becomes

pliable or moldable above a specific temperature and solidifies upon cooling.

Eg Teflon,nylon

Thermo setting resins are used as the principal polymer component due to their high thermal stability

and resistance to a wide variety of chemiclas.

The aggregates used in dry state can be silicates, quartz, crushed stone, gravel,

Filler, especially fly ash, can improve the properties of polymer concrete.

PROPERTIES

The properties of PC are largely dependent on the amount and properties of polymer in the concrete.

Each type of polymer can imparts specific properties to Polymer Concrete when incorporated with the

aggregates.

So Depending on the properties of the Polymer Concrete to be achieved, the nature and quantity of the

polymer composition should be chosen.

PC made with MMA is a brittle material that shows a nearly linear stress-strain relationship with high

ultimate strength, but the addition of butyl acrylate produces a more ductile material.

As yet, there is no polymer which can serve for all drawbacks of the concrete.

Polymer concrete may be used for new construction or repairing of old concrete because of rapid

curing, excellent bond to cement concrete and steel reinforcement, high strength, and durability, it was

extensively used as repair material. Precast polymer concrete has been used to produce a variety of

products like acid tanks, manholes, drains, highway median barriers, and so forth

The adhesive properties of polymer concrete allow patching of both polymer and conventional cement-

based concretes.

These composites have some advantages compared to ordinary cement concrete such as: rapid

hardening, high mechanical strengths, chemical resistance, etc.

Advantages

Rapid curing at ambient temperatures

High tensile, flexural, and compressive strengths when fibre reinforcement is used

Good adhesion to most surfaces

Good long-term durability with respect to freeze and thaw cycles

Low permeability to water and aggressive solutions

Good resistance against corrosion

May be vibrated to fill voids in forms

Disadvantages

Product hard to manipulate due to its strength and density

It tends to be brittle in nature i.e. if fiber reinforcement is not provided in some polymer concrete cases

they tend to develop cracks

Polymer concretes are viscoelastic and will fail under a sustained compressive loading at stress levels

greater than 50 percent of the ultimate strength. Sustained loadings at a stress level of 25 percent did

not reduce ultimate strength capacity for a loading period of 1000 hr. So in such cases polyester

concrete should be considered with a high ratio of live load to dead load

Among the disadvantages is their high cost. Small boxes are more costly when compared to its precast

counterpart however pre cast concretes induction of stacking or steel covers quickly bridge the gap.

Various curing regimes have been reported by researchers like room temperature curing, high

temperature curing, water curing, and so forth.

Curing time studies on polymer concrete have established that it achieves around 70–75% of its

strength after a curing of one day at room temperature whereas normal Portland cement concrete

usually achieves about 20% of its 28-day strength in one day.

The early strength gain is important in precast applications because it permits the structures to resist

higher stresses early due to form-stripping, handling, transportation, and erection operations.

Author Resin Aggregate and

micro filler

used

Variables Properties

evaluated

Brief findings

Compressive strength, flexural strength, and so forth

Mani et al. Epoxy,

polyester

Crushed

quartzite,

siliceous sand,

and calcium

carbonate

Resin type,

silane treatment,

and micro filler

addition

Compressive

strength, flexural

strength, and split

tensile strength

(I) Epoxy concrete has

much superior properties

than the polyester

concrete.

(ii) Compressive strength

goes up by 30% for the

polyester concrete and

36% for the epoxy

concrete by incorporation

of a silane coupling

agent.

(iii) The compressive and

flexural strengths of the

polyester concrete are

greatly improved on

incorporation of the

micro filler.

Vipulanandan

et al

Epoxy,

polyester

Ottawa sand,

blasting sand

Resin content,

silane treatment,

compaction, and

glass fiber

content

Compressive

strength, flexural

strength, and split

tensile strength

(I) Maximum

compressive and flexural

strength were reported at

14% resin content.

(ii) Addition of glass

fibers increases the

flexural strength,

compressive strength.

(iii) Silane treatment

increases the flexural

strength by 25%.

Vipulanandan and

Paul [62]

(I)

Epoxy,

(ii)

polyester

Ottawa

sand,

blasting

sand

Temperature,

strain rate,

aggregate type,

and curing

conditions

Compressive

strength, split

tensile

strength

(I) Compressive

strength increases

with curing

temperature.

(ii) Maximum

strength was

obtained for one-

day room

temperature

curing followed

by one-day curing

at 80°C.

(iii) Use of gap

graded aggregate

resulted in highest

compressive

strength.

GEO POLYMER CONCRETE

‘Geopolymer cement concretes’ (GPCC) are Inorganic polymer composites, which are prospective

concretes with the potential to form a substantial element of an environmentally sustainable

construction by replacing/supplementing the conventional concretes.

GPCC have high strength, with good resistance to chloride penetration, acid attack, etc.

Geopolymer cements cure more rapidly than Portland-based cements. They gain most of their strength

within 24 hours. However, they set slowly enough that they can be mixed at a batch plant and delivered

in a concrete mixer. Geopolymer cement also has the ability to form a strong chemical bond with all

kind of rock-based aggregates

The term ‘geopolymer’ was first introduced by Davidovits in 1978 to describe a family of mineral

binders with chemical composition similar to zeolites but with an amorphous microstructure.

Two main constituents of geopolymers are: source materials and alkaline liquids. The source materials

on alumino-silicate should be rich in silicon (Si) and aluminium (Al).

They could be byproduct materials such as fly

ash, silica fume, slag, rice-husk ash, red mud, etc.

These are commonly formed by alkali activation

of industrial aluminosilicate waste materials such

as FA and GGBS, and have a very small

Greenhouse footprint when compared to

traditional concretes

Geopolymers are also unique in comparison to

other aluminosilicate materials (e.g.

aluminosilicate gels, glasses, and zeolites).

The concentration of solids in geopolymerisation

is higher than in aluminosilicate gel or zeolite synthesis.

Composition of Geopolymer Cement Concrete Mixes

Following materials are generally used to produce GPCCs:

1. Fly ash,

2. GGBS Ground granulated blast furnace slag (GGBS)

3. Fine aggregates and

4. Coarse aggregates

5. Catalytic liquid system (CLS): It is an alkaline activator solution (AAS) for GPCC. It is a

combination of solutions of alkali silicates and hydroxides, besides distilled water. The role of

AAS is to activate the geopolymeric source materials (containing Si and Al) such as fly ash and

GGBS.

Formulating the GPCC Mixes

Unlike conventional cement concretes, GPCCs are a new class of materials and hence, conventional

mix design approaches are applicable.

The formulation of the GPCC mixtures requires systematic numerous investigations on the materials

available.

Preparation of GPCC Mixes

The mixing of ingredients of GPCCs can be carried out in mixers used for conventional cement

concretes

– Such as pan mixer, drum mixer, etc.

In geopolymer concrete, aggregates are bound by binder which is composed from two parts including

alumina silicates and alkali solution and named geopolymer binder.

Mix proportioning is based on determining the quantities of the ingredients, when mixed together and

cured properly will produce workable concrete that achieves the desired strength and durability when

hardened.

Therefore different variables including desired workability measured by slump, water to binder ratio,

binder content and aggregate proportions should be considered in the mix design procedure.

In geopolymer concrete based on alkali activated fly ash the weight ratio of alkali solution to fly ash is

suggested in the range of 0.3 to 0.45

Geopolymer concrete Casting and Curing

The equipment’s needed for geopolymer concrete production are the same as OPC concrete.

Usually for casting this type of concrete, fundamental materials such as fly ash and aggregates are

mixed and alkaline solution with additives are added to it. Curing at elevated temperature helps the

reaction of the paste in geopolymer concrete.

Curing time and temperature have an effective role on compressive strength of geopolymer concrete.

Two curing conditions can be considered which are fog and sealed conditions.

It is shown that sealed condition shows around 15% more compressive strength than samples are cured

at steam condition

Properties

Compressive Strength: With proper formulation of mix ingredients, 24 hour compressive strengths of

25 to 35 MPa can be easily achieved without any need for any special curing. Such mixes can be

considered as self-curing. However, GPCC mixes with 28 day strengths up to about 60-70 MPa have

been developed at SERC.

Modulus of Elasticity The Young’s modulus or modulus of elasticity (ME), Ec of GPCC is taken as

tangent modulus measured at the stress level equal to 40 percent of the average compressive strength of

concrete cylinders. The MEs of GPCCs are marginally lower than that of conventional cement

concretes (CCs), at similar strength levels.

Stress Strain Curves The stress-strain relationship depends upon the ingredients of GPCCs and the

curing period.

Rate of Development of Strength This is generally faster in GPCCs, as compared to CCs.

The properties of geopolymers based on different alumina silicates are summarized as below:

Alkali activated slag

Alkali activated slag cements have been known for about four decades and usually for activation2-7

percent Na2O or 3-10 percent K2O of the slag content is necessary.

This kind of concrete has shown progressive gain of strength from 21Mpa in 3days to 36Mpa in 1 year

and to 40Mpa in 6years (for a concrete mix having binder content 350Kg/m3, binder to aggregate ratio

of 1:5.96, water to binder ratio of 0.46 and MSA of 25mm) .

When alkali-activated slag cement concrete is cured in water, compressive strength of the concrete

keeps increasing until 365 days.

However, if the concrete is cured in a sealed condition, the strength stopped increasing at about 90

days. This may be attributed to the lack of moisture available for the hydration of slag inside the

concrete.

The concrete exposed to air exhibits the lowest strength all the time and strength retrogression occurs at

ages greater than 28 days.

The strength reaches a maximum after 14 to 28 days of hydration, and then starts to decrease

Alkali activated fly ash

Although there are only a few reports regarding the flexural strength and elastic modulus of alkali

activated fly ash (AAFA), it seems that both show inferior values to those of Portland cement.

It was also reported that the flexural strength of alkali activated PFA mortars are 5.79 MPa while OPC

based mortars are 7.76 MPa.

The values presented for OPC concrete ranged from 30.3 to 32.3GPa while for geopolymer concrete

they ranged from 10.7 (without silicate) to 18.4 GPa (with silicate). It was observed better elastic

modulus results for a concrete samples made in similar conditions: 22.95 to 30.84 GPa.

Apart from their short setting times compared to conventional concrete, geopolymers also attain higher

unconfined compressive strengths and shrink much less on setting than OPC (for 7 days only 0.2% that

of OPC while for 28 days it is 0.5% of OPC) .

One explanation for this behavior may be found in the microstructural characteristic of the new binder

which in alkali activation of fly ash can form a zeolite-type phase. Zeolite properties and

microstructure are widely known to be unaffected by the loss of the water incorporated during their

synthesis because not only water loss is reversible in most zeolites but also they are able to absorb

water from the humidity in atmosphere

Alkali activated Natural Pozzolana

Geopolymeric concrete mixes based on activated natural pozzolans mostly have shown lower strength

and modulus of elasticity than OPC mixes at early ages, but they reach the same and even higher

strength and modulus of elasticity than OPC mixes after long-term curing.

It is concluded that concrete made with an alkali activated natural pozzolana develops moderate to high

mechanical strength and modulus of elasticity and shrinks much less than ordinary OPC.

All of the geopolymer concrete mixes show lower ultrasonic pulse velocity than OPC concrete mixes

even though they have higher compressive strengths despite lower densities

shrinkage during setting

compressive strength (uniaxial): > 90 MPa at 28 days (for high early strength formulation, 20 MPa

after 4 hours).

flexural strength: 10–15 MPa at 28 days (for high early strength of 10 MPa after 24 hours).

Young Modulus: > 2 GPa.

freeze-thaw: mass loss < 0.1% (ASTM 4842), strength loss <5 % after 180 cycles.

Geopolymer binders and cements even with alkali contents as high as 10%, do not generate any

dangerous Alkali-Aggregate Reaction..

Geopolymer concretes develop moderate to high mechanical strength with a high modulus of elasticity

and shrinkage much lower than with OPC.

Geopolymer concrete manufacture is liable to reduce CO2 emission from 22.5% to 72.5% compared to

OPC production.

Geo-polymer concrete can be produced with the same cost of OPC concrete and comparable properties.

Energy needs and CO2 emissions for 1 tone of Portland cement and Rock-based Geopolymer cement.

Energy needs(MJ/ton) Calcination Crushing Silicate Sol. Total Reduction

Portland Cement 4270 430 0 4700 0

GP-cement, slag by-product 1200 390 375 1965 59%

GP-cement, slag manufacture 1 950 390 375 2715 43%

CO2 emissions (tone)

Portland Cement 1.000 0.020 1.020 0

GP-cement, slag by-product 0.140 0,018 0.050 0.208 80%

GP-cement, slag manufacture 0.240 0.018 0.050 0.308 70%

1

3

2. POLYMER MODIFIED CONCRETE

It is also known as polymer cement concrete

Polymer modified concrete is gaining popularity because of its ease of handling, economy and

satisfactory results when compared with its counterparts

It has high chemical resistance.

Low water absorption and permeability make it an effective material for use in hydraulic structures as

well.

It has the property of setting quickly

PREPARATION

It is made by mixing cement,aggregates,water and polymer

Such mixture is cast in moulds,cured dried and then polymerized

The polymers that are used in this process are

1. Poly butadiene styrene

2. Epoxy styrene

3. Furans

Among these epoxy resin is mostly used because of the superior charecteristics it possessed in

comparison with the ordinary concrete the addition of latex provides a large quantity of the needed

mixing water in concrete

Epoxy resin is a better binder than cement.

PMC is made with as low as possible addition of extra mixing water as possible

Typically, water-cement ratios are in the range 0.40 to 0.45.

The hardening of a latex takes place by drying or loss of water.

Dry curing is mandatory for LMC; the material cured in air is believed to form a continuous and

coherent polymer film which coats the cement hydration products, aggregate particles, and even the

capillary pores.

PROPERTIES

The most impressive characteristics of PMC are its ability to bond strongly with old concrete, and to

resist the entry of water and aggressive solutions.

It is believed that the polymer film lining in the capillary pores and micro cracks does an excellent job

in impeding the fluid flow in PMC, these characteristics have made the PMC a popular material for

rehabilitation of deteriorated floors, pavements, and bridge decks.

Each type of polymer latex can and usually does impart specific properties to PMC when incorporated.

As yet, there is no polymer latex to serve a universal purposes.

Depending on the properties of the PMC to be achieved, the nature and quantity of the polymer

composition should be chosen.

Superior polymer concrete was obtained by the addition furfural alcohol and aline hydrochloride in the

wet mix

It claimed to be a specially dense and non-shrinking material and to have high corrosion resistance low

permeability and high resistance to abrasions

Epoxy resin produced a concrete that showed some superior charecteristics over ordinary Portland

cement

Table 1 shows the general characteristics and typical applications of some widely used polymer latex.

Table 2 summarizes the property variation factor F of the PMC product as compared to Portland

cement concrete (defined as the ratio between the parameter of PMC and that of the conventional

mortar or concrete prepared under identical conditions).

Disadvantages

Modest improvement of strength and durability

Materials poorer than OPC are obtained

This shows that monomers ae incompatible with aqueous solutions and interfere with the cement

hydration process

3.POLYMER IMPREGNATED CONCRETE

PREPARATION

It is one of the widely used polymer concreting methods

Produced by impregnating or infiltrating a hardened concrete with a monomer

The concept underlying PIC is that if voids are responsible for low strength as well as poor durability

of concrete in severe environments, then they should be eliminated by filling with a polymer

It is difficult for a liquid to penetrate it if the viscosity of the liquid is high and the voids in concrete are

not empty (they contain water and air).

Therefore by filing polymer voids are closed.

Therefore, for producing PIC, it is essential not only to select a low-viscosity liquid for penetration but

also to dry and evacuate the concrete before subjecting it to the penetration process.

A conventional concrete is taken and completely cured and dried in an oven there by removing any

kind of air is removed after which monomer is applied onto it

The amount of manner that can be loaded into a concrete specimen is dependent upon the amount of

water and the air space that was occupied on the specimen

So for proper application of this process the specimen should be completely dried so that monomer is

completely penetrated

For best results the lesser the pores, the less the monomer required and less will be the monomer

loading time

Monomers such as methyl methacrylate (MMA) and styrene are commonly used for penetration

because of relatively low viscosity, high boiling point (less loss due to volatilization), and low cost.

The types of monomer used are

1. Methylmetharylate

2. Styrene

3. Other thermoplastic monomers

After penetration, the monomer has to be polymerized insitu. This can be accomplished in one of three

ways.

A combination of promoter chemical and catalysts can be used for room-temperature polymerization;

but it is not favored because the process is slow and less controllable.

Gamma radiation can also induce polymerization at room temperature, but the health hazard associated

with it discourages the wide acceptance of this process in filed practice.

The third method, which is generally employed, consists of using a monomer-catalyst mixture for

penetration, and subsequently polymerizing the monomer by heating the concrete to 70 C with steam,

hot water, or infrared heaters

Sequence Of Operation

Casting conventional concrete elements:

Since the quality of concrete before penetration is not important from the standpoint of properties of

the end product, no special care is needed in the selection of materials and proportioning of concrete

mixtures.

Section thickness is generally limited to a maximum of about 150 mm, since it is difficult to fully

penetrate thick sections.

Drying and evacuation:

The time and temperature needed for removal of free water from the capillary pores of moist-cured

products depend on the thickness of the elements.

At the drying temperatures ordinarily used (i.e.,105 C), it may require 3 to 7 days before free water has

been completely removed from a 150- by 300-mm concrete cylinder.

Temperatures on the order of 150 C can accelerate the drying process so that it is complete in 1 to 2

days

Soaking the dried concrete in a monomer

The in situ penetration of concrete in the field may be achieved by surface ponding, but precast

elements are directly immersed in the monomer catalyst mixture.

Commercial monomers contain inhibitors that prevent premature polymerization during storage;

The catalyst serves to overcome the effect of the inhibitor.

Sealing the monomer

To prevent loss of monomer by evaporation during handling and polymerization, the impregnated

elements must be effectively sealed in steel containers or several layers of aluminum foil; in the

rehabilitation of bridge decks this has been achieved by covering the surface with sand

Polymerizing the monomer

Thermal-catalytical polymerization is the preferred technique.

The time for complete polymerization of the monomer in the sealed elements exposed to steam, hot

water or air, or infrared heat at 70 C may vary from a few to several hours.

In the case of a MMA-benzoyl peroxide mixture, no differences in strength were found between

specimens polymerized at C with hot air for 16 hr. or with hot water for 4 hr.

Curing the elements

Following the removal of elements from forms, at ambient temperatures conventional moist curing for

28 days or even 7 days is adequate because the ultimate properties of PIC do not depend on the

penetration concrete quality.

For fast production schedules, thermal curing techniques may be adopted

PROPERTIES

The degree of polymerization of monomer is greater in case of PIC specimen prepared by microwaves

than ones prepared from conventional thermal methods.

The mechanical and chemical resistant properties of PIC composites are superior to the conventional

cement mortar.

Porosity

Porosity of the conventional

cement mortar is greatly reduced

when it is impregnated with

polymers thereby increasing its

durability when it is exposed to

chemically polluted

environments.

Polymers give a more compact

structure to the cement matrix

and seal the cracks in cement

mortar matrix

Microstructural studies

The porosity and morphology of

the polymer cement matrix in the PIC was studied.

The porosities of conventional cement mortars and the PICs were found to be 17.3% and 9.8%

respectively.

Fig.3 Comparison of the Pore diameter in OPC and PIC specimens

The decrease in porosity in the latter case could be attributed to the sealing of the voids and micro‐

cracks by the polymer in the precast cement mortar thereby increasing durability and strength of the

cement structure as seen in the previous section

Durability

Fig.2 and Table 1 depicts the chemical resistant properties of the PICs on exposure to 5M sulphuric

acid were compared with

Those obtained for conventional cement mortar by calculating the weight losses for different periods of

exposure time.

The presence of the polymer in a PIC not only envelopes the cement mortar but also seals the voids

formed during the cement hydration.

This prevents cement‐acid interactions that would otherwise result in loss of weight of the composite

Compressive strength increases and is different for different

composition and on type of polymers used.

Tensile strength increases and is different for different composition

and on type of polymers used.

4. PARTIALLY IMPREGNATED AND SURFACE COATED

CONCRETE

Partial impregnation may be sufficient in situations where the major requirement is surface resistance

against chemical and mechanical attack in addition to increase in its strength

Even with partial impregnation significant increase in the strength of concrete of original concrete has

been obtained

The partially impregnated concrete can be easily produced by initial soaking the dried specimens in the

liquid monomer like MMA,then sealing them by keeping them under hot water at 70c to prevent or

minimize loss due to evaporation

The polymerization can be done using thermal catalyst method in which 3% by weight of benzoyl

peroxide is added to the monomer as catalyst

The depth of monomer penetration depends upon

Pore structure

Duration of soaking

Viscosity of the monomer

PREPARATION

The surface is dried for several days with electric heating blanket

Remove the blanket and cover the slab with oven dried light weight aggregate

Apply initially around 2000 to 3000 ml of the monomer system per sq.m.

Cover the surface with polyethylene to retard evaporation

Shade the surface to prevent temperature increase which might initiate polymerization prematurely

Add periodically addtl. Monomer to keep the aggregate moist for min soak time of 8 hours

Apply heat to polymerize the monomer

Heat blanket or steam water can be used for this purpose

ADVANTAGES

It reduces freeze thaw deterioration, corrosion

Increase in tensile strength

Increase in compressive strength

Increase in modulus of elasticity

Resistance to acid attack

It improves the durability of concrete

Less pores

They are more or less similar to PIC

FIBRE REINFORCED POLYMER

CONCRETE

PREPARATION

A large number of studies have been reported regarding the effect of reinforcement of polymer

concrete by addition of various types of fibers. Steel fibers, glass fibers, carbon fibers, and polyester

fibers have been added in polymer concrete in varying quantities for enhancement of its properties.

Polymer concrete can be reinforced with fibers like: glass, carbon, boron or natural fibers like: coconut,

banana fibers, sugar cane bagasse, cellulose.

In the case of natural fibers only coconut fibers can be excellent reinforcement for polymer concrete

Fracture properties can be improved by addition of short glass or carbon fibers.

Sugar cane bagasse can be an alternative for using as reinforcement.

Most of the studies have reported the addition of glass fibers in the range of 0 to 6% by weight of

polymer concrete.

These fibers are oriented randomly or in a proper at the time of concrete mix

For polymer concretes in particular, natural or synthetic fibers – such as carbon or glass fibers – can be

added to the PC matrix to improve the mechanical performance.

Glass fibers are non-corrosive, non-conductive and non-magnetic and offer low density and high

modulus.

Mechanical improvement depends on the fiber type and on its concentration in the PC.

For example glass and organic fibers have little effect on the precracking behavior but do substantially

enhance the post-cracking response, which leads not only to improved toughness and ductility but also

to higher tensile, flexural and impact strength.

A special case of fiber reinforcement is the addition of oriented fibers. Reinforcement glass fibers and

plastic bars placed along the principal stress directions reduce the creep deformation, which if present

to a large degree might result in an impaired structure or even cause structural collapse.

The orientations of fibers play a key role in determining the capacity of concrete.

If the reinforcements are placed in desired direction. But in FRC, the fibers will be oriented in random

direction. The FRC will have maximum resistance when fibers are oriented parallel to the load applied

PROPERTIES

It has been reported that addition of glass fibers improves the post peak behavior of polymer concrete.

The strength and toughness of polymer concrete also increase with addition of fibers.

Few studies on silane treatment of glass fibers before their use in polymer concrete report an

enhancement in mechanical properties up to the extent of 25%.

Table 1 provides the details of the various types of reinforcements and their effect on the properties of

polymer concrete as reported by various researchers.

Heat assisted drying of the aggregates before mixing with resin has been suggested by most of the

researchers. It has been reported that water content of the aggregate has a remarkable influence on the

strength of polymer concrete and therefore the water content shall be limited to 0.1%.to 0.5% for better

mechanical properties

A shortcoming of using fibers in concrete is reduction in workability.

As fiber content increases, workability decreases. Most researchers limit volume of fibers to 4.0%

It has been reported that addition of glass fibers improves the post peak behavior of polymer concrete.

The strength and toughness of polymer concrete also increase with addition of fibers

Table 1: Fiber reinforcements and their effect on polymer concrete.

Author Resin Aggregate Fibers addition Properties evaluated Brief findings

Broniewski

et al. [55] Epoxy resin Sand

Steel fibers of

0.24 mm diameter

and 15 mm

length, added in 0

to 3.5% by

weight

Flexural strength,

creep

Addition of 3.5%

steel fibers

increases the

flexural strength by

40%.

Valore and

Naus [56]

Polyester,

vinylester,

epoxy

—

Nylon, glass,

aramid, steel

fibers of length

12.7 to 38.1 mm

Compressive

strength, Young’s

modulus, split

tensile strength, and

density

(i) Compressive

strength increases

as function of

density.

(ii) Flexural

strength is related

to compressive

strength (inPsi)

as psi.

(iii) Fiber addition

increases flexural

strength and

ductility.

(iv) Longer fibers

have better effect

on compressive

strength.

The current knowledge about effects of fiber reinforcement (with random distribution, not

unidirectional) on strength of several specific types of polymer concretes is summarized as follows:

For polyester PC with fiber glass

Reinforcement, the compressive strength values depend on the percentage of polyester resin in the mix

and the concentration of fiber glass.

For each resin content, there is an optimal fiber content (based on maximum strength).

Values of the modulus of elasticity in compression (e) decrease when the fiber content increases.

On the other hand, there is an increase in e with increasing polyester resin content.

With respect to the failure strain property, values increase when the glass fiber content increases.

For PC with 10 % polyester resin content, failure strain goes from 0.013 to 0.024 mm/mm as fiber

content increases from 0 to 6 vol. %.

For polyester PC, improvement of 95 % in the flexural strength has been obtained when adding 2 % of

glass fibers and using silane as coupling agent.

For

TEXTILE FIBRES

The textile cutting waste, when mixed with thermosetting, epoxy resin and foundry sand produce a

unique composite material the can be used for lightweight construction. The composite material pro-

duced exhibits lower flexural and compressive characteristics when reinforced with textile cutting

wastes, i.e. textile fibers when added to polymer concrete mixture does not accomplish the expected

reinforce or at least has the same strength characteristics of unreinforced polymer concrete.

Textile fibers do not increase polymer concrete flexural and compressive strength but their addition to

the mixture eliminates the signs of brittleness behavior of unreinforced polymer concrete. The use of

those fibers, in specific applications, may solve two problems, namely, elimination of an environmental

pollutant and provision of an alternative material for the construction industry

The results displayed in fig.7 show that flexural strength of polymer concrete made with textile fibers

decrease with the increase of textile fibers content.

Ultimate failure load decrease is observed in all cases and failure becomes even less brittle, especially

for 12% resin content polymer concrete reinforced with 2% of textile fibers. The unreinforced speci-

mens collapse catastrophically and textile reinforced has a more soft failure, avoiding specimens from

break completely, failure occurred but specimens did not break apart.

Increasing resin content increases the flexural strength in both formulations, unreinforced and textile

fiber reinforced polymer concrete. This behavior was expected according to previous studies

From fig.7, it is clear that increasing resin and fiber content higher flexural strength is obtained.

Fig.3 presents compressive strength comparison of all formulations tested plain and textile reinforced

polymer concrete.

Table 1. Mix proportion of PC formulations.

Test series Resin: sand (w.w–1) Fiber content (%)

Flexural

EPO100F 10:90 0

EPO101F 10:90 1

EPO102F 10:90 2

Compressive

EPO120C 12:88 0

EPO121C 12:88 1

EPO122C 12:88 2

CONCLUSIONS

Polymer concrete may be used because of rapid curing, excellent bond to cement concrete and steel

reinforcement, high strength, and durability; it was extensively used as repair material.

Compressive strength and tensile strength vary with temperature and polymer used

The strength of polymer-modified concrete is greatly influenced by the mixing ratio of ingredients and

type of the polymer used.

Polymer concretes are viscoelastic and will fail under a sustained compressive loading if the load is

much greater than the ultimate load

The presence of the polymer in a PIC not only envelopes the cement mortar but also seals the voids

formed during the cement hydration, this prevents cement‐acid interactions that would otherwise result

in loss of durability of the concrete, Low permeability to water and aggressive solutions, good chemical

resistance and resistance against corrosion

Micro filler is also often added to polymer concrete mix to reduce the void content in aggregate

mixture and thereby increase the strength of polymer concrete like fly ash, silica….

Studies have shown that small size of spherical particles also contributes to a better packing of the

aggregate materials which reduces porosity and hinders the penetration of aggressive agents, thus

considerably improving the chemical resistance of polymer concrete.

Enhancement in compressive strength up to 30% has been reported by addition of 15% fly ash in

polymer concrete.

Textile fibers do not increase polymer concrete flexural and compressive strength but their addition to

the mixture eliminates the Signs of brittleness behavior of unreinforced polymer concrete. The use of

those fibers, in specific applications, may solve two problems, namely, elimination of an environmental

pollutant and provision of an alternative material for the construction industry

Addition of glass fibers improves the post peak behavior of polymer concrete.

The strength and toughness of polymer concrete also increase with addition of fibers

Geopolymer cements offer an alternative to, and potential replacement for, ordinary Portland cement

(OPC). Geopolymer technology also has the potential to reduce global greenhouse emissions caused by

OPC production but also possesses excellent mechanical properties (strength & durability).

Aging infrastructure can be repaired using PMC, and It showed excellent bonding with old concrete

Although polymer concrete might initially seem a bit more expensive when compared to conventional

materials because of the monetary cost per unit weight,

It will appear extremely feasible when judged on its low maintenance requirements, its durability and

other parameters.

This material has excellent potential for use in various fields in and it seems to be on the right path in

initiating research into applications of PMC.

As yet, there is no polymer to serve universal purposes.

PLACES OF APPLICATION

PMC is widely used for floor and bridge overlays, floor tiles, building cladding, hazardous waste

containment, post-tensioned beams and slabs, and stay-in place formwork ,also precast PC was used for

drains, underground boxes, manholes, acid tanks and cells, tunnel lining, shells, floor tiles, architectural

moldings and machine tools and bases.

70–75% of its strength after a curing of one day at room temperature , whereas normal Portland cement

concrete usually achieves about 20% of its 28-day strength in one day. The early strength gain is

important in precast applications because it permits the structures to resist higher stresses early due to

form-stripping, handling, transportation, and erection operations.

The low permeability and corrosive resistance of polymer concrete allows it to be used in swimming

pools, sewer structure applications, drainage channels, electrolytic cells for base metal recovery, and

other structures that contain liquids or corrosive chemicals.

Prior to deciding what repair material to use, make sure you know what the intent is: Are you trying to

bond a crack together or just cover it up?

How quickly do you want the repair to achieve full strength?

How important is compressive strength or flexural strength? How about abrasion resistance?

It is especially suited to the construction and rehabilitation of manholes due to their ability to withstand

toxic and corrosive sewer gases and bacteria commonly found in sewer systems.

It can also be used as a bonded wearing course for asphalt pavement, for higher durability and higher

strength upon a concrete substrate.

High-strength lightweight polymer concrete could be a solution in such application for structures are

heavy and require heavy reinforcements for making cantilevers and walls.

For some concrete repairs, the best repair material is simply high quality concrete. polymers leading to

higher bond strength and durability

PMC possess excellent bonding ability to old concrete, and high durability to aggressive solutions; it

has therefore been used mainly for overlays in industrial floors, and for rehabilitation of deteriorated

bridge decks

In the case of PIC, by effectively sealing the micro cracks and capillary pores, it is possible to produce

a virtually impermeable product which gives an ultimate strength of the same order as that of PC.

Geopolymer concrete drawback such as loss of workability, quick setting time and the health and

safety implications of working with strong alkali sol can easily be adapted in applications such as pre

cast concrete and mass concretes as a dam construction where roller compacted geopolymer concrete

can be construction method. It can also be used as waste water pipe line, hydraulic structures.

This type of concrete, especially in countries with greater resources of natural pozzolana and alumina

silicate by products, can help decrease energy consumption and environmental impacts

FUTURE SCOPE

Polymer-modified concrete materials are a very promising group of new building materials. They

possess remarkable potential due to a wide variety of interesting features, properties and applications.

Such materials can respond to the many needs of current and future construction works.

Structures in hostile environments, inaccessible for repair, or subject to impact, cyclic, or dynamic

loading could benefit from PMC.

The properties of individual polymers and polymer modified concretes have been investigated by

several researchers.

High cost of polymers may limit the use of these materials in repairs and rehabilitation of concrete

structure for practical applications. However, their use with other subsidiary chemicals could reduce

their cost. This cost reduction may, therefore, help to promote the use of polymer in concrete. Hence,

cheaper polymers may be made for this purpose

Further developments in polymer concrete may lead to common usage of the material in additional

infrastructure applications

Polymer concrete has historically not been widely adopted due to the high costs and difficulty

associated with traditional manufacturing techniques. However, recent progress has led to significant

reductions in cost, meaning that the use of polymer concrete is gradually becoming more widespread

PMC materials have the potential to be used in residential and other civil constructions

GPCC offers an alternative and potential replacement for OPC, because of its effect in reducing the

greenhouse emissions produced during the manufacture or processing of OPC. Because of lower

internal energy (almost 20% to 30 % less) and lower CO2 emission contents of ingredients of

geopolymer based composites compared to those of conventional Portland cement concretes, the new

composites can be considered to be more eco-friendly and hence their utility in practical applications

needs to be developed and encouraged

On March 2010, the US Department of Transportation Federal Highway Administration released a

TechBrief titled Geopolymer Concrete that states:[3]

The production of versatile, cost-effective

geopolymer cements that can be mixed and hardened essentially like Portland cement represents a

game changing advancement, revolutionizing the construction of transportation infrastructure and the

building industry

REFERENCES

1. Polymer Concrete And Its Potential In The Construction Industry By Luke M. Snell,1 H. Aldridge

Gillespie, And Robert Y. Nelson

2. Polymer Concretes: A Description and Methods For Modification And Improvement By Martinez-

Barrera, E. Vigueras-Santiago, O. Gencel And H.E. Hagg Lobland

3. Mechanical Properties Of Polymer Concrete By Raman Bedi, Rakesh Chandra, And S. P. Singh

4. Indian Concrete Journal-Geo Polymer Concrete,December2014

5. Geopolymer Concrete - A New Eco-friendly Material of Construction by N. P. Rajamane,India.

6. Geo-polymer Concrete as a New Type of Sustainable Construction Materials by Dali Bondar,Iran

7. Pakistan Journal Egg. & Appl. Sci. Vol. 8, Jan., 2011 (P. 21-25) Development Of Economical

Polymer-Modified Concrete For Repair Of Concrete Structures In Pakistan By Muhammad Farhan

Arooj, Sajjad Haydar And Kafeel Ahmad

8. January 2011,The Indian Concret Journal, Polymer-Modified Concrete: World Experience And

Potential For Bangladesh By M.A. Islam, M.M. Rahman And M. Ahmed

9. Physical And Chemical Properties Of Polymer Impregnated Concrete On The Preparation Conditions

By Won Mook Lee, J Priya Nair, Chul Woo Lee, Du Hyun Ku, Jeong Soon Park,Hun Young Park

10. P.K. Mehta And P.J.M. Monteiro, Concrete: Microstructure, Properties, And Materials

11. Concrete Technology By M.S.Shetty

12. Google Books

13. Materials Research, Vol. 12, No. 1, 63-67, 2009,Effect Of Textile Waste On The Mechanical Properties

Of Polymer Concrete By João Marciano Laredo Dos Reis, Universidade Federal Fluminense,Brazil

14. Properties Of Fiber Reinforced Polymer Concrete By Marinela B ˘ Arbut¸ ˘a, And Maria Harja

15. www.concretenetwork.com

16. www.hindawi.com

17. www.wikipedia.com

18. www.nbmcw.com