13

Chapter – 2: LITERATURE REVIEW

S.No Name of the sub-title Page No

2.1 Cement and its characteristics 14

2.1.1 Cement Particle Size 14

2.1.2 Cement Additives 17

2.1.3 Cement particle size distribution 23

2.1.4 Particle size distribution measurement 24

2.1.5 Significance of particle size distribution 26

2.1.6 Influence of particle size distribution 27

2.2 Use of waste materials in cementation 34

2.2.1 Thermal Power industry waste (Fly Ash) 34

2.2.2 Granite industry waste 35

2.2.3 Slate mine effluent 36

2.2.4 Plastic waste 38

2.3 Influence of bacteria and response surface in building compressive strength

40

14

Chapter – 2

LITERATURE REVIEW

2.1. Cement and its characteristics

2.1.1. Cement Particle Size

Conventionally use of two cements are in popular usage viz. Ordinary

Portland cement (OPC) and Portland Pozzalona Cement (PPC). Particle size

distribution of both the cements are more or less same, PPC cement being little

finer as it is obtained from ultra fine separators like electrostatic precipitators

and bag filters. The range or cement particles is between 0.1 µm to 90 µm. The

production of particle size depends on crushing and grinding machinery,

retention time of operation, and efficiency of separation in equipments like

classifier, cyclone separator and bag filters. The precision of particle size

distribution depends basically on efficiency of classifier.

The increment of cement strength is especially influenced up to seven

days because of the increase in particle fineness [14]. Increase in particle

fineness will have a significant contribution to strength results. The increase in

particle fineness does not have an influence on portland pozzolan cements’

initial set time, however, it considerably decreases final setting time of portland

pozzolana cements.

15

In any reaction, a finer material is likely to react more quickly than a

coarser material and cement is no exception. Differences in cement particle

size, expressed as fineness or surface area, will affect strength development.

Cement doesn’t follow the appropriate composition of particle size distribution,

yields lesser strength [15]

The fineness of grounded cement will certainly affect the rate of strength

development. Grinding the cement more finely will result in a more increment

in strength. Fineness is often expressed in terms of total particle surface area,

eg: 400 m2/ kg. However, importance as fineness of particle size distribution of

the cement has to qualify certain range of particle size distribution with respect

to surface area.

Fineness has a greater effect on 2 days strength, and in lateral curing,

strength is affected more by the amount of coarse particles rather than fines.

The fine and coarse tails of the distribution of a particular cement have

different effects on strength. If both ends of fines and coarse fractions are

reduced, and the distribution is made to be uniform, yields, high strength

values. Considering water demand and setting characteristics, some

operational parameters in the separation process can be rearranged to obtain

higher strength products.

It had been found that, coarser cements require more time to achieve set,

although they achieve set at a lower degree of hydration. Their strength

development will also lag significantly, in comparison to finer cements [16].

16

Coarser cements require more hydration for the capillary porosity

inferring a possibly enhanced curability. Coarser cements will require more

attention to be paid during curing, to achieve their full potential. If adequate

curing doesn’t happens then finer cements are preferable due to increased

early hydration rate, which minimizes water consumption.

Coarser particles will require more time for setting, where as finer

particles will require less time, and the heat release by coarser particles is

lesser in comparison to finer particles, the diffusion coefficient for coarser

particles is higher than finer particles [17]. Fineness is very important for

strength development, smaller surface area and narrow size distribution yields

very good strength [12]

Studies using novel sensors have demonstrated that the cement particle

size distribution has its influence on initial pore size distribution of cement

paste has a significant effect on the early age cement properties at water to

cement ratios [18]. Larger pores present in cement reduces rate of relative

humidity with an increase in hydration. Therefore production of uniform

particle size distribution of cement may be one of the methods of reducing early

age cracking.

2.1.2. Cement Additives

Cement is added with the following additives in order to maintain

effective usage and quality:

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1. Gypsum

2. Fly ash

3. Iron industry slag

4. Lime stone / lime

2.1.2.1. Gypsum

Gypsum is added to retard the setting time of cement, and about 2 % of

gypsum is added in cement. Cement produced without adding gypsum yields

quick hardening, and will not allow for conveyance lag. After preparing the

mortar, adequate time is required for conveying from mortar preparation zone

to end use zone. In order to retard the setting time gypsum is added, which

retard the setting time up to 180 min. Setting time is measured in two ways

viz. initial setting time and final setting time. In initial setting the cement

mortar tend to start setting and in final setting the cement occupies hardened

structure, and will not be possible to mould. In conventional practice gypsum

is measured as SO3 content, according to National standards and International

standards. Presence of SO3 gives direct indication of gypsum.

Gypsum consists of calcium sulfate dihydrate, which is a soft material

with the chemical formula CaSO4.2H2O [19-20]. Gypsum is used to promote

soil strength for fertilizer; it has its many constituents of plaster and is widely

mined [21]. Gypsum word has been derived from the Greek work gypsum

means chalk or plaster [22].

18

Gypsum also serves as a nutrient for plant growth, and during early 19th

century, it had been regarded as micaculous fertilizer [23]. The solubility of

gypsum in water is moderate with 2-2.5 g/l at 25oC [24], it has a retrograde

solubility, transforming less soluble during higher temperatures.

Natural gypsum occurs as flattened and in twinned crystals with

transparency, cleavable masses termed selenite, which has no significant

selenium, instead, the names of both substances were termed for the ancient

Greek word Moon [25]. Such crystals form largest crystals in nature up to 14

meters, which will be in selenite form [26]. The resources occur in strata as

Archaean eon [27].

Since gypsum dissolves in water, gypsum is not found as a form of sand,

but the parameters of white sands national monument in the US state of New

Mexico has a creation of 710 km2, of white gypsum in sand form, which will be

enough to be supplied to construction industry in drywall for about 1000 years

[28].

The occurrence of gypsum is also found in Mars Reconnaissance Orbiter

(MRO), which has an indication of existence of gypsum resources in the

northern polar regions of Mars [29], these were later affirmed at ground level by

the Mars Exploration Rover(MER) [30].

Gypsum resources are commercially available in Araripinna and Grajau

in Brazil, Pakistan, Jamaica, Iran, Thailand, Spain, Europe, Germany, Italy,

England, Ireland, Canada [31] and United States. The temperatures at 58oC

19

and the resource was filled with rich water drives the crystal growth. The huge

crystals weighing 55 tons and is around 500000 year old [32].

A newer approach had been suggested that the formation of gypsum

starts as small crystals of a mineral matter called bassanite (CaSO4.0.5H2O)

[33].

Gypsum is used in a large span of applications like production of

gypsum board [34] which is primarily used to finish walls and ceilings, and is

known in constriction industry as dry wash, or plaster board. Gypsum has its

application in plaster ingredient in surgical operations. Gypsum also has its

use as a fertilizer and soil conditioner [35]. Gypsum also had been used as a

wood substitute in construction [36]. Gypsum is also mixed with soy bean

curd, to make it a resource of calcium, in traditional use of dairy products.

Gypsum is added to water to promote hardness for home brewing [37]. It is also

used in bakery as a calcium resource [38] and food for yeast [39]. Small

fractions of gypsum are mixed to cement to retard setting.

Amin A. Hanhan stated [40], about the requirement of gypsum content

for the lowest expansion and for the highest compressive strength of the

Portland cement mortars, and exposed to sodium sulfate environment. This

optimum was not the same for both expansion and strength [40]. The findings

of this study did indicate that increasing the gypsum content above 3.0% for all

the cements, decreases durability of mortar exposed to sulfate environment.

20

2.1.2.2. Fly Ash

Thermal power stations produce huge volumes of flush ash, upon

burning coal. During initial days of thermal power stations, it had been a

difficult task to manage the fly ash, since the size is very fine, and is subjected

to fly in environment causing damage to human being by way of skin irritation

and dermatitis. Fly ash was also damaging plants and crops. Large volumes of

water were being sprinkled on the fly ash heap, before it was taken to land

filling or ocean dumping. Off late, scientists discovered the effective utilization

of fly ash as an additive in cement, as similar components of inorganic

materials present in fly ash viz. silica, alumina and traces of iron. According to

BIS a maximum of 35 % fly ash can be added in OPC cement, such cement is

called Portland Pozzalana Cement (PPC). Fly ash added cement has advantages

over conventional OPC cement in terms of price, durability and especially

managing the environment. The fineness of fly ash is important in maintaining

quality of cement.

It had been found that up to 110% of strength activity index can be

achieved when coarse fly ash is ground to smaller size [41].

Strength Activity Index (SAI) = (A/B) x 100

Where A = average compressive strength of fly ash-cement mortar

B = average compressive strength of control mortar

21

Strength activity index of coarse fly ash can be improved by enhanced

grinding and coarse fly ash is not to be in crystalline phase. Good quality fly

ash can be accomplished by having proper classifiers or furthermore grinding

the coarse fly ash. Smaller particle sizes of fly ash increases rate of reaction in

turn enhance the compressive strength. With classifying or grinding processes,

setting times of all fly ash-cement pastes are acceptable as the standards are

met with ASTM (American Society for Testing and Materials). When keeping the

same workability of mortar, the use of smaller sizes of fly ash demands less

water than for the coarser one.

Volume expansion values of PPC are lower than OPC volume expansion,

which has the same fineness. When particle fineness increases, volume

expansion values increase a little.

2.1.2.3. Iron Industry Slag

Iron industry produces huge volumes of slag by way of clusters, as a

waste material, in the treatment of iron ore. It had been a problem for iron

industrialists in managing the slag waste. The waste was conventionally being

used for land filling. Since the slag consists of small percentages of iron, silica

and alumina, since all these compounds are present in cement, grounded slag

was started to be mixed with OPC cement, such cement is called Portland Slag

Cement, which comprises of little more or less strength in comparison to OPC

cement. A maximum of 35 % of slag is being used to mix in OPC cement.

Since the slag is of harder in nature, it erodes the life of balls used in final

22

stage of cement mill production, however use of slag is there in production of

specialty cements.

2.1.2.4. Lime Stone / Lime

The degree of cementation depends on the association of limestone and

lime with silica, alumina and iron. After final production of cement, limestone

and lime is added to govern the degree of cementation. Lime stone and or lime

is grounded to approximately 50 µm size and mixed with cement.

Coarser lime stone can be replaced with cement with less water/cement

(w/c) ratio, without compromising the compressive strength of cement [42].

Optimal quantity of lime stone can be replaced for better performance of

cement [43]. Approximately 20% of Lime stone when mixed with clinker and

gypsum, yielding enhanced properties of cement with decreased porosity in

cement mortar [44]. When high lime fly ash is mixed with ordinary Portland

cement, the strengths increases during all ages of curing, when compared to

low lime fly ash mix with ordinary Portland cement [45].

2.1.3. Cement Particle Size Distribution

Physical constituents like particle size distribution, homogeneity of

distribution, and specific surface area (SSA) are very important for any cement.

A particular range of size fractions affect strength density, especially fine and

coarse ends. Fineness is an important parameter for early day strengths.

23

Similar strength may be obtained for samples with a narrower distribution of

smaller SSA [46].

The particle size distribution (PSD) of a powder, or granular material, is a

list of values or a mathematical function that defines the relative amounts of

particles present, sorted according to size.

Based on the particle size distribution several equations has been

developed, which will estimate the strength of cement [47]. When fly ash is

classified in 19.1 and 6.4 micro meter fractions and blended with ordinary

cement, yielded higher compressive strength, in comparison to original fly ash

[48]. Fly ash fineness less than 10 micron is a crucial parameter in strength

development of cement. The compressive strength of cement enhanced when

cured at higher temperatures [49]. Calcium content and fly ash particle

distribution is the most important parameter in compressive strength of

cement [50]. The compressive strength of PPC cement increases when fly ash

fraction increases. Less than 10 micro meter fly ash has been crucial in

strength development [51]. Replacement of ultra fine fly ash of 8% has been

found to be yielding higher compressive strength [52].

2.1.4. Particle Size Distribution Measurement

The following techniques are used to measure, particle size distribution

of any powder

1. Sieve analysis

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2. Air elutriation analysis

3. Photoanalysis

4. Optical counting methods

5. Electro resistance counting methods

6. Sedimentation techniques

7. Laser diffraction methods

The Particle Size Distribution (PSD) is expressed usually by the method

by which it is estimated. The most easily understood method of estimation is

sieve analysis, where powder is separated on sieves of different sizes, and

subjected to sieving. Therefore, the PSD is defined in terms of discrete size

ranges, based on the sieves used: e.g. "% of sample between 45 μm and 53

μm"[53]. The PSD is usually estimated over a list of size ranges that covers

nearly all the sizes present in the sample. There are some methods which allow

much narrower size ranges to be determined than obtained by sieves, and are

applicable outside the range of availability of sieves. However, the idea of the

"sieve", that "retains" particles above a certain size, and "passes" particles

below that size, is universally used in presenting PSD data for all technical

utility [53].

The PSD may be expressed as a ”range" estimation, where the amount is

listed in the order. PSD may also be present in conventional practice in terms

of "cumulative" form, where the total of all sizes “retained" or "passed" by a

single "sieve" is given for a range of sizes and the range analysis is appropriate

25

when a particular range of particle is required, while cumulative analysis is

used where the amount of "under-size" or "over-size" is to be controlled [53].

In general "size" is expressed and is open to a wide range of

interpretations. A simple treatment assumes the particles to be spheres that

will just pass through a square hole in particular "sieve" [53]. In general

practice, particles having irregular shape, example in the case of fibrous

materials, the way in which such particles are characterized during analysis

vary depending on the method of measurement used.

Sample analysis is done to find particle size distribution of a representing

sample/material. A particle size distribution can be displayed either in tabular

or graphical form or as a cumulative distribution.

2.1.5 Significance of Particle Size Distribution

The PSD cement is important to understand its physical and chemical

response, since it of a material is important in understanding its physical and

chemical properties, since it affects the strength and load bearing properties. It

also affects the nature of reaction and needs to be closely monitored in

production.

The PSD may be represented as a "range" analysis, in which the amount

of each size range is listed in order. It may also be expressed in "cumulative"

form, in which the total of all sizes "retained" or "passed" by a single notional

26

"sieve" is given for a range of sizes. The range analysis is suitable when a

particular size is required [54].

The size of the particle affects the property of powders in many ways. It

effects the setting time of cement, the hiding powder of pigments, the activity of

chemical catalysts, the taste of food, and the potency of drug and sintering

shrinkage of powders. Thus for quality control of the final product, it is very

much essential to maintain particle size distribution of the powder [53].

In Cement production the product is characterized by the percentage

below a mesh or sieve opening (95% below 90 micron is generally

recommended) or by the Blaine (Surface area) value.

Particle size is an important property and is used to characterize a

powder in bulk. It affects the following properties

1. surface area

2. packing density (bulk density, tapped density, Husner’s ratio)

3. strength of the compacts

4. tensile strength

5. flow properties

It is possible to get high strength with lower Blaine number. This is

possible only when attempt is made to analyze the size distribution of the

powder.

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2.1.6. Influence of Particle Size Distribution

Particle size distribution has a direct influence on the following

1. Bulk density

2. tapped density

3. Husner’s ratio

4. Specific surface area

By varying particle size distribution, the properties like bulk density,

tapped density, Husner’s ratio and specific surface area can be varied, and has

an impact on final quality of cement. The objective of current work is to study

particle size and distribution and correlating the values like bulk density,

tapped density, Husner’s ratio and specific surface area. It is hoped that the

above mentioned four properties can be modified towards increasing cement

quality.

2.1.6.1. Bulk Density

Bulk density is one of the properties of powder characteristics of powders

and granules, and is being used as a measure of quality of a chemical

substance, soil, gravel, pharmaceutical, food stuff or any other material of

particulate matter. It is estimated as the mass of material divided by the total

volume of the mass. The total volume infers inter-particle voidage and internal

pore volume [55].

28

Bulk density is not the inherited property of a material, and can change

depending on how the material is produced. If a powder is poured into a

cylinder will occupy particular bulk density, and if the cylinder is mildly or

completely tapped, it will have a different volume, and the bulk density of that

tapped mass is termed as tapped density.

The bulk density of a particular soil depends on the mineral composition

and the size of particles. The density of quarts will be around 2.65 g/cc and the

dry bulk density of a mineral soil will be about half of the density 1 to 2.65

g/cc. Organic compounds will have a bulk density below 1 gram per cubic

centimeter.

Bulk density of any soil can be determined using a core sample which is

taken by inserting a metal corner inside the soil at a particular depth and

horizon [56]. This will give a soil sample of known gross volume of which, wet

bulk density and the dry bulk density can be estimated [57].

For the measurement of wet bulk density, total mass including moisture

is measured and divided by the total volume, and for measurement of dry bulk

density mass of sample after drying is considered and divided by the total

volume.

The dry bulk density of a particular soil is inversely proportional to

porosity of the same soil. Higher the pore space, lower will be the value of bulk

density. Bulk density of a particular region in the earth crush is related to

29

sesmic velocity of waves travelling through the bed, for P-waves, this had been

quantified with Gardner’s relation as higher the density, faster the velocity.

2.1.6.2. Tapped Density

Tapped density is measured as the ratio of tapped mass to tapped

volume. In most of the operations, especially in pharmaceutical industries,

tapped density plays a vital role in signifying the properties of flowability,

compaction and compression. During the production of cement, a certain

proportion of particle size distribution is necessary in order to maintain the

quality, which can also be governed by the values of tapped density.

2.1.6.3. Husner’s ratio

Husner’s ratio is a dimension less number which correlates to flowability

of powders or granular material. It had been named after the engineer Henry

H. Husner (1900-1995) [58-59].

Hausner’s ratio can be calculated by the formulae

H = Tapped bulk density/ bulk density

Hausner’s ratio is not an absolute property of the material, its value

changes with respect to methodology used to determine it as well as machinery

used for producing powders.

30

Husner’s ratio has been used in wide scope of industries [60-64], as an

indication of powder properties, especially flowability [65]. Hausner ratio

greater than 1.25 is an indication of poor flowability. Hausner’s ratio is also

related to Carrr index, which is another indication of flowability.

H = 100/ (100-C)

Both Hausner’s ratio and Carr index has some deviations in some

products.

Productions of powders from bulk solids, pellets and granules has been

the demand in almost all industries due to its magnificent property of

enhanced surface area which is responsible for promoting faster conversions.

Powders are basically produced using size reduction machinery like crushers

(gyratory, blake jaw crushers) and grinders (ball mill, hammer mill and fluid

mill). The properties of powders produced from different grinders possess

different properties [66]. The nature of powders is analyzed by its

characterization (bulk, tapped density, flowability, etc.) [67], one of the

important physical properties is bulk density, which is used as a reference

during production and packaging. Among all the properties, bulk density plays

a greater role in signifying nature of the compound and tapped density gives

idea about size, shape, sphericity and porosity of bed [68]. Flowability or

Hausners ratio is measured as the ratio of bulk density to tapped density and

it gives a dimension less number as flowability index [66]. Husner’s ratio less

than 1.25 is an indication of good flowability. Flowability index greater than

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1.25 indicates poor flowability and leads to cohesiveness. Established research

proves, crystal size and shape has an impact on bulk density of powder [69].

Particle size and shape of mixer has an impact on volume reduction due to

packing [70]. Tapped density is measured in order to have an idea of

cohesiveness, compatibility and flowability of powder [71]. Bulk density is also

a phenomenon of measurement of flowability of powder [72]. Flowability index

has been considered as an essential parameter in transportation of powders,

and in order to promote flowability, dry powder coatings are added in

pharmaceutical industries [73]. Flowability also gives an idea about filling

properties which helps in packing and formulation. It is measured by using

angle of repose, and is directly proportional to flowability [74]. Many

experiments have been carried out to assess the flowability of powder using

advance methods like vibrating capillary method, modified warren spring

cohesion tester and Jenikie shear tester method [75]. Transportation of fine

powder has been a complex task due to size, shape, and lesser bulk density,

leading to compactness [76]. Size and shape of pharmaceutical powder depends

on the process of nucleation, crystal growth and crystallization [77]. Longer

storage of powder leads cohesiveness thereby decreasing flowability, due to

these reasons materials were stored for specific duration [78]. Shape and size

also plays a vital role in compactness and flowability of powders [79], due to

these reasons there is a need to standardize powder in order to produce

homogenous quality. The present investigation is aimed to study the

measurement of bulk, tapped density and Husner’s ratio which are the key

32

properties in handling powders and to find out the variance in values and its

causes.

2.1.6.4. Specific Surface Area

Specific surface area is the property of solid powders which is the total

surface area of a material per unit mass of sample [80], solid or bulk volume

[81]. The units of surface area are m2/kg, or m2/m3. As the particle size

decreases, surface are of total particulate mixture increases. Specific surface

area measurement can be done by methylene blue (MB) stain test, ethylene

glycol monoethyl ether (EGME) method [82], and Brenauer Emmett-Teller (BET)

adsorption method and Protein Retention (PR) method [83-84].

Conventional method of estimation of cement surface area is done using

blaines apparatus, which works on a principle called flow through packed bed,

where Kozeney Caramen equation is used.

One of the constituents of cement is volatile organic/inorganic material,

which can be analyzed by the test called Loss on Ignition, this test is done by

strongly heating the sample in a muffle furnace at a specified temperature, by

which volatile substance will be escaping, until its mass remains constant.

This can also be done using air, or in some inert condition. The test consists of

placing of few grams of material in a crucible and measuring the initial mass,

then keeping it in a furnace and the difference in mass is termed to be loss on

ignition. The process may be repeated for obtaining consistent values.

33

Loss on ignition is represented as part of oxide or elemental analysis of a

mineral. The material escaped or lost during heating usually consists of

moisture content and carbon dioxide from carbonates. It can be used as a test,

usually carried out for mineral matter such as iron ore. The test is also carried

out for estimating un-burnt carbon in fly ash.

During the process of pyroprocessing industries like lime, calcined

bauxite, cement manufacture, the loss on ignition of raw material will be

around the loss in the mass than undergo in the kiln. Likewise for minerals the

loss on ignition presents the actual material lost at smelting or refining during

the furnace and smelter operation. The value of the sample also indicates the

probability of incompletion of pyro-processing. The standard ASTM test defines

for limestone and lime and cement along with other samples [85-86].

So far research has been done in the area of studying the particle size

distribution of cement and its impact on compressive strength. Current

research is intended to work on study of different constituents of cement

(multiple brands of samples) viz. physical constituents like < 10 µm, < 30 µm

<53 µm particles, and chemical constituents like loss on ignition (LOI), gypsum

(SO3), insoluble residue (IR), then analyze using JMP software towards finding

quantified constituents for obtaining higher compressive strength.

It is also aimed to study and analyze range of physical parameters like

bulk density, tapped density, Husner’s ratio, and specific surface area, which

are associated with the above mentioned physical and chemical constituents

34

(< 10 µm, < 30 µm, <53 µm particles, LOI, SO3, IR) and its correlations to find

out range of specifications for producing high quality cement, and validate of

range of constituents/model developed by JMP software.

2.2. Use of waste materials in cementation

In India about 960 million tones of solid waste is generated annually as

bi-product from different industrial processes out of which approximately 350

million tones are from organic agricultural sources, 290 million tones inorganic

wastage from industrial mining and 4.5 million tones are hazardous waste.

Part of the waste from different industries has been recycled in construction

industry as well as other industries [87]. Use of municipal solid waste

incinerated fly ash is found to be effective up to 20%, as cement substitute

[88]. Muscovite granite waste has the ability to produce ceramic tiles by adding

20-30 % [89].

Based on the fact that fly ash which consists of silica, alumina and iron

can be mixed with cement, several other materials consisting of similar

chemical composition were explored to be used as a cementing material, like

slag of iron industry, nodules of granite waste, sludge of tiles industry etc.,

2.2.1. Thermal Power industry waste (Fly Ash)

Fly ash is produced at thermal power stations as a waste material, when

huge volumes of coal are burnt in boilers. The flu gas is made to pass through

electrostatic precipitators, and the fine dust (fly ash) is collected. Fly ash

35

consists of silica, calcium oxide, and traces of alumina as well as iron, which is

cementing compatible material, and matches with the composition of granite

saw dust. Earlier fly ash was considered as waste and was used for land filling,

similarly granite waste is presently used in land filling, similarly in current

practices granite waste is considered to be the solid waste and is being

disposed for land filling.

Ordinary Portland Cement (OPC) is commonly used as a best means of

cementing material for construction, with different grades including 33, 43 and

53 grade, available in the market as per Bureau of Indian Standards (IS:

12269: IS 1489:2005). Off late as the demand of quick hardening raised from

the customer, cement industries concentrated to produce 53 cement, and off

late cement industries realizes the potentiality of mixing solid waste produced

from thermal power industries and started mixing with OPC cement of 43

grade standard and produced fly ash mixed cement PPC.

Portland Pozzolana Cement (PPC) is produced by mixing a maximum of

35% (BIS: IS 1489: 1991) of fly ash in OPC cement. A maximum of 35% fly ash

is being added to OPC, and available in market as PPC [90].

2.2.2. Granite industry waste

Granite industry produces huge volumes of granite saw dust, during the

production of granite sheets from slabs. The granite saw dust comprises of

calcium and iron which has the compatibility to acid soils, granite waste

powder is used as a suitable means to neutralize acid soils [91]. Use of granite

36

and marble rock waste found to be effective in the production of concrete for

civil construction [92]. In Brazil, granite waste powder has been effectively

studied and proved compatible for making ceramic bricks and tiles, the results

have been acknowledged by Brazil standardization for ceramic bricks and tiles

[93]. Granite sludge waste is found to be effective filler for pozzolanic motors,

where a reddish pigment is produced by calcining at lower temperature (700-

9000C) for short time, therefore granite sludge can be an effective additive in

the preparation of colored motor [94]. The sludge produced from granite cutting

polish industries is also found to be effective up to 10 % mixing to produce roof

tiles with enhance properties [95]. Granite waste is also found to be effective

up to 40 % (Mg by weight) in producing fly ash magnesium oxy chloride cement

[96]. Granite waste is currently used for land filling at most of the industries in

India. Since granite consists of silica, alumina and alumina which is also

present in cement. However, granite waste was not used as cementing material.

2.2.3. Slate Mine Effluent (SME)

Slate is conventionally used as a mean of preliminary learning, being

used to write using slate pencils. Slate is produced from slate mines which is

basically quarts, excavated from the mine and then processed to produce a flat

plate of around 3 mm thickness. During the process of production of slate lot

of water remain as slate mine effluent (SME).

The slate effluent will also affect the plant and animal lives directly in

their growth directly as well as harm human being indirectly through food

chain Because of the impurities present in slate mine effluent. The growth of

37

plants was observed to be sluggishing, when effluent was used to water

conventional plants, which is because of excess toxic compounds present in

effluent [97]. Presence of aluminium concentration in effluent streams

demonstrated to be toxic for plants with sluggishness in growth and

productivity [98]. Plants require some amount of salt to be present in the

medium viz. soil, sand, and water. Higher concentrations of salts were

observed to decay the plant growth [99]. The stipulated values are set by

central pollution control board as well as state pollution control board, towards

the biotic life. Concentrations beyond in effluent found to be toxic in fishes

leading to depletion in life cycle [100].

Waste effluent generated from different industries was exploited for

effective utilization in construction. The compressive strength and other

properties of cement are increasing when underground water is used in

comparison with tap water [101]. The compressive strength of cement

decreases when waste water generated in oil fields is used in construction, this

could be due to the nature of oil particulates, which are basically organic in

nature, where as cement is an inorganic material [102]. Waste water coming

over from ready mix preparation plants can be a best substitute to be used for

mortar preparation, it reduces the capillary nature of cement [103]. Use of

sludge water in concrete mix can be an option for effective utilization of sludge,

but it has its positives and negatives, where by such sludge can be used for

constructing boundary wall bricks in ground floor [104]. Use of concrete plant

sludge with a maximum of 6% solids is recommended to use in cement mortar,

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without compromising the quality of cement, in terms of mechanical properties

[105].

2.2.4. Plastic Waste

Plastic is an organic material prepared from petrochemicals having

unique properties extensively utilized by man kind in different domains

including packaging, storage, handling, instrumentation, automobiles and

construction. The uniqueness being light in weight, good thermal and

electrical insulation, corrosion resistant, easy workability, insect resistant,

chemical inertness, high refractive index, and good strength. Common man is

comfortable and enjoying the usage of plastics. Unfortunately the disposal has

not been implemented properly. Across the communities it is observed littering

of plastic carry bags, tea cups, water bottles, which damages the ecology of soil

and water by way of impact on flora, fauna and other ecological cyclic

compounds [106].

On an average 10000 tons of plastics is being discarded as waste on to

the soil/water bodies, out of which a maximum of 45% is being recycled, rest

55% is entraining into the environment, which will have an impact on the

nature depleting ecological cycles like hydrogen, nitrogen, carbon, phosphorous

etc., plastic is the best material to be used in all domains, provided if it

circulates among the men [107]. Hazards of plastic occur only when it goes

into the nature (water & soil). Effective utilization of plastic waste is found

conventional in road lying. In Tamilanadu most of the roads were laid and has

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better properties than the conventional cement [108] used plastic mass

particles incorporated as aggregate in concrete and tested the chemical,

physical, and mechanical properties. Most of the plastic waste > 20 µm in

thickness [108] is recycled after subjecting it to series of mechanical unit

operations like leveling, cutting, shredding, and separation.

Before the advent of cement, during ancient times, lime mortar was

effectively used by adding jaggery as a binder. The historic construction

‘Charminar’ in Hyderabad was constructed by lime mortar. Based on the

established research facts [109] plastic is an effective means to be used as an

aggregate. Use of plastic in lime mortar, as well as other mortars is explored in

the current study, towards finding compatibility of cementation.

2.3. Influence of bacteria and response surface in building Compressive strength

The strength of concrete observed to be increasing upon mixing

Sporoscarcina pasteurii bacteria, when mixed with fly ash mixed cement, as

well as the water absorption was reduced to four times. Sporoscarcina

pasteurii bacteria was also mixed in silica fumes cement mix, where 5-10 % of

silica fumes were present, the studies depicts enhancement of compressive

strength up to 20 %[110, 111].

Response surface area plots developed using variables and fractional

factorial design, helps in maintaining consistent concrete quality[112].