CHAPTER 1 1.1 INTRODUCTION

1.1.1 Cement:

Cement is an extremely good material having adhesive and cohesive properties which

provide a binding medium for discrete ingredients. It is obtained from burning together in a

definite portion a mixture of naturally occurring argillaceous and calcareous material to partial

fusion at high temperature (about 1450ºc) .The product, called Clinker, is cooled and ground to

the required fineness to produce the material known as cement. Depending upon the location of

the cement manufacturing plant available materials are pulverized and mixed in proportions such

that the resulting mixture will have the desired chemical composition. The lime stone, clay are

the basic ingredients, the proportions will be approximately four pats of limestone to one part of

clay. Depending upon the wide variety of raw material used in the manufacturing of cements, the

oxide composition of ordinary Portland cement is as follows:

Table 1: Oxide composition of ordinary Portland cement:

OXIDE PERCENTAGE AVERAGE

Lime, CaO 60-65 63

Silica, SiO2 17-25 20

Alumina,Al2O3 3-8 6

Iron oxide Fe2O3 0.5-6 3

Magnesia MgO 0.5-4 2

Sulpher trioxide, SO3 1-2 1.5

Soda and/or potash Na2O+K2O 0.5-1 1

1.1.2 The various types of cement are:

Rapid-hardening Portland cement

Portland –slag cement

Low heat Portland cement

Portland Pozzolona cement

1

High strength Portland cement

Super Sulphate cement

High alumina cement

Waterproof cement

White Portland cement

Coloured Portland cement

Hydrophobic cement.

1.1.3 Storage of cement bags:

It is often necessary to store cement bags for long period, although cement retains its

quality almost its quality almost indefinitely if moisture is kept away from it. The cement

exposed to air absorbs moisture slowly and this causes its deterioration. Absorption of 1 or 2 %

of water has no appreciable effect but further amount of moisture absorption retards the

Hardening of cement.

Cement in bulk can best be stored in bins of depth 2m or more. Usually a crest of about

5cm thick forms and this must be removed before cement is taken for use. The bagged cement

can also be kept for months, if stored in water proof shed, with non porous walls and floors and

windows being tightly shut. Once the cement has been properly stored it should not be disturbed

until it is to be used.

1.2 Natural Sand:

Sand is a loose, fragmented, naturally-occurring material consisting of very small

particles of decomposed rocks, corals, or shells. Sand is used to provide bulk, strength, and other

properties to construction materials like asphalt and concrete. It is also used as a decorative

material in landscaping. Specific types of sand are used in the manufacture of glass and as a

molding material for metal casting. Sand was used as early as 6000 B.C. to grind and polish

stones to make sharpened tools and other objects. The production of sand for construction

purposes grew significantly with the push for paved roads during World War I and through the

1920s. The housing boom of the late 1940s and early 1950s, coupled with the increased use of

concrete for building construction, provided another boost in production.

2

Today, the processing of sand is a multi-billion dollar business with operations ranging

from very small plants supplying sand and gravel to a few local building contractors to very

large, highly automated plants supplying hundreds of truckloads of sand per day to a wide

variety of customers over a large area.

Sand that is scooped up from the bank of a river and is not washed or sorted in any way is

known as bank-run sand. It is used in general construction and landscaping.

The definition of the size of sand particles varies, but in general sand contains particles

measuring about 0.063-2.0 mm in diameter. Particles which are smaller than this are classified as

silt. Larger particles are either granules or gravel, depending on their size. In the construction

business, all aggregate materials with particles smaller than 6.4 mm are classified as fine

aggregates. This includes sand. Materials with particles from 6.4 mm up to about 15.2 cm are

classified as coarse aggregates.

Sand has a density of 1,538-1,842 kg per cubic meter. The trapped water content between

the sand particles can cause the density to vary substantially. [9]

1.3 Foundry Sand:

Foundry sand is a high-quality silica sand that is used to form moulds for ferrous (iron

and steel) and nonferrous (copper, aluminium, brass, etc.) metal castings. The most common

casting process used in the foundry industry is the sand cast system, in which the sand moulds,

chemically bonded sand cast systems are used. These systems involve the use of one or more

organic binders in conjunction with catalysts and different hardening/setting procedures.

Chemical binders include phenolic, furfuryl alcohol, and other inorganic binders. Foundry sand

makes up about 97 percent of this mixture. Chemically bonded systems are most often used for

"cores" (used to produce cavities that are not practical to produce by normal moulding

operations) and for moulds for nonferrous castings.

Excess foundry sand is typically generated because varying amounts of the previously

mentioned additives must continually be reintroduced to the foundry sand to maintain its desired

properties, resulting in a larger volume of sand than is needed for the foundry process. Addition,

3

heat and mechanical abrasion eventually render the sand unsuitable for use in casting moulds,

and a portion of the sand is continuously removed and replaced with fresh unused sand. The

spent sand is either recycled in a non-foundry application or land filled. Of the 6 to 10 million

tons of spent foundry sand generated annually, less than 15 percent is recycled. Thus in order to

reuse this foundry sand, attempts have been made in using this foundry sand in replace to the

natural sand in the concrete technology for the reasons such like,Concrete is a mixture comprised

of cement (10-15 percent), coarse and fine aggregates (60-75 percent) and water (15-20 percent)

by volume.   Foundry sand can be used as a fine aggregate substitute in concrete.  Fine

aggregates are generally smaller, while coarse aggregates are in diameter.  Foundry sand meets

two of the critical requirements for concrete aggregates as it is uniformly graded, and is strong,

hard, and durable.

A foundry is a manufacturing facility that produces metal castings by pouring molten

metal into a preformed mold to yield the resulting hardened cast. The primary metals cast include

iron and steel from the ferrous family and aluminum, copper, brass and bronze from the

nonferrous family. [1]

1.3.1 Manufacturing of Foundry Sand:

Foundry sand is high quality silica sand that is a byproduct from the production of both

ferrous and nonferrous metal castings. The physical and chemical characteristics of foundry sand

will depend in great part on the type of casting process and the industry sector from which it

originates.

Foundries purchase high quality size-specific silica sands for use in their molding and

casting operations. The raw sand is normally of a higher quality than the typical bank run or

natural sands used in fill construction sites. The sands form the outer shape of the mould cavity.

These sands normally rely upon a small amount of Bentonite clay to act as the binder material.

Chemical binders are also used to create sand “cores”. Depending upon the geometry of the

casting, sands cores are inserted into the mold cavity to form internal passages for the molten

metal. Once the metal has solidified, the casting is separated from the molding and core sands in

the shakeout process.

In the casting process, molding sands are recycled and reused multiple times. Eventually,

4

the recycled sand degrades to the point that it can no longer be reused in the casting process. At

that point, the old sand is displaced from the cycle as byproduct, new sand is introduced, and the

cycle begins again.

.

1.3.2 Types of foundry sands:

Two general types of binder systems are used in metal casting depending upon which the

foundry sands are classified as: clay bonded systems (Green sand) and chemically bonded

systems. Both types of sands are suitable for beneficial use but they have different physical and

environmental characteristics.

Green sand moulds are used to produce about 90% of casting volume. Green sand is

composed of naturally occurring materials which are blended together; high quality silica sand

(85-95%), betonies clay (4-10%) as a binder, a carbonaceous additive (2-10%) to improve the

casting surface finish and water (2-5%). Green sand is the most commonly used recycled

foundry sand for beneficial reuse. It is black in color, due to carbon content, has a clay content

that results in percentage of material that passes a 200µ sieve and adheres together due to clay

and water.

Chemically bonded sands are used both in core making where high strengths are

necessary to withstand the heat of molten metal, and in mould making. Most chemical binder

systems consist of an organic binder that is activated by a catalyst although some systems use

inorganic binders. Chemically bonded sands are generally light in color and in texture than clay

bonded sand. Foundries produce Recycled Foundry Sand (RFS) generally in their overall

production volume although there are different sand to metal ratios employed in different

casting processes and products. Most foundries have two sand systems one feeding the external

moulding lines and the other feeding the internal core lines. After the metal is poured and the

part is cooling, green sand is literally shaken off the castings, recovered and reconditioned for

continual reuse. Used cores are also captured during this cooling and shake out process; these

break down and are crushed and reintroduced into green sand systems to replace a portion of

sand lost in the process. Broken cores are cores, which do not break down, are discarded.

Depending on the projected end use, it may be important to segregate sand streams at the

foundry as each stream can have different characteristics. Additionally some sand is typically

unrecoverable during shake off and finishing processes. These sands may be contaminated with

5

metals or very large chunks of burnt cores and will need to undergo some type of segregation,

crushing and screening before recycling.

1.3.3 Properties of foundry:

1.3.3.1 Physical Properties:

Typical physical properties of waste foundry sand from green sand systems are given in

Table-10. The grain size distribution of waste foundry sand is very uniform, with approximately

85 to 95 percent of the material between 0.6 mm and 0.15 mm (No. 30 and No. 100) sieve sizes.

5 to 12 percent of foundry sand can be expected to be smaller than 0.075 mm (No. 200 sieve).

The particle shape is typically sub angular to round. Waste foundry sand gradations have been

found to be too fine to satisfy some specifications for fine aggregate. Waste foundry sand has

low absorption and is non plastic. Reported values of absorption were found to vary widely,

which can also be attributed to the presence of binders and additives. The content of organic

impurities (particularly from coal binder systems) can vary widely and can be quite high. This

may preclude its use in applications where organic impurities could be important (e.g., Portland

cement concrete aggregate). The specific gravity of foundry sand has been found to vary from

2.39 to 2.55. This variability has been attributed to the variability in fines and additive contents

in different samples. In general, foundry sands are dry, with moisture contents less than 2

percent. A large fraction of clay lumps and friable particles have been reported, which are

attributed to the lumps associated with the moulded sand, which are easily disintegrated in the

test procedure. The variation in permeability, listed in Table-10, is a direct result of the fraction

of fines in the samples collected.

Durability of the foundry sand depends on how the sand was used at the foundry.

Successive moulding can cause the foundry sand to weaken due to temperature shock. At later

stages of mould use, this can lead to the accelerated deterioration of the original sand particles.

However, in civil engineering uses, the foundry sand will not normally be subjected to such

severe conditions.

1.3.3.2 Chemical Composition:

6

Chemical Composition of the foundry sand relates directly to the metal moulded at the

foundry. This determines the binder that was used, as well as the combustible additives.

Typically, there is some variation in the foundry sand chemical composition from foundry to

foundry. Sands produced by a single foundry, however, will not likely show significant variation

over time.

Foundries often produce consistent sands. The chemical composition of the foundry sand

can impact its performance. Waste foundry sand consists primarily of silica sand, coated with a

thin film of burnt carbon, residual binder (bentonite, coal, resins) and dust. Silica sand is

hydrophilic and consequently attracts water to its surface. This property could lead to moisture-

accelerated damage. Additives may be required to counteract such problems. Depending on the

binder and type of metal cast, the pH of waste foundry sand can vary from approximately 4 to 8.

It has been reported that some spent foundry sands can be corrosive to metals. Because of the

presence of phenols in foundry sand, there is some concern that precipitation percolating through

stockpiles could mobilize leach able fractions, resulting in phenol discharges into surface or

ground water supplies. Foundry sand sources and stockpiles must be monitored to assess the

need to establish controls for potential phenol discharges.

Table 2: Chemical compositions of foundry sand:

Sr.NoProperties

Result (%)

1.Sio2

87.91

2.Al2O3

4.70

3.Fe2O3

0.4

4.CaO

0.14

5.MgO

0.30

7

6.SO3

0.09

7.Na2O3

0.19

8.K2O

0.25

9.TiO2

0.15

10.P2O5

0.00

11.Mn2O3

0.02

12.SrO

0.03

13.LOI

5.17

Total=99.87

1.3.4 How is it produced?

Foundry sand is produced by five different foundry classes. The ferrous foundries (gray

iron, ductile iron and steel) produce the most sand. Aluminum, copper, brass and bronze produce

the rest. The 3,000 foundries in the United States generate 6 million to 10 million tons of foundry

sand per year. While the sand is typically used multiple times within the foundry before it

becomes a byproduct, only 10 percent of the foundry sand was reused elsewhere outside of the

foundry industry in 2001. The sands from the brass, bronze and copper foundries are generally

not reused. While exact numbers are not available, the best estimate is that approximately 10

million tons of foundry sand can beneficially be used annually.

Foundry sand is basically fine aggregate. It can be used in many of the same ways as

natural or manufactured sands. This includes many civil engineering applications such as

8

embankments, flow-able fill, hot mix asphalt (HMA) and Portland Cement Concrete (PCC).

Foundry sands have also been used extensively agriculturally as topsoil.

Currently, approximately 500,000 to 700,000 tons of foundry sand are used annually in

engineering applications. The largest volume of foundry sand is used in geotechnical

applications, such as embankments, site development fills and road bases.

1.3.5 Foundry Waste Sand: A Scenario in India:

The Indian foundry industry is the fifth largest in the world. There are more than 6,000

foundries in India, and they have a combined installed capacity of approximately 7.5 metric

tonnes per annum (MTPA). Most foundries (nearly 95%) in India fall under the small and

medium scale category and are located in clusters. These units produce a wide range of castings

that include automobile parts, agricultural implements, machine tools, diesel engine components,

manhole covers, sewing machine stands, pump-sets, decorative gates and valves.

Table 3: Details of major foundry clusters with major products in India:

As shown in the table, no.3 of foundries in Maharashtra contributes a major role in

production of waste foundry sand, Kolhapur region being one of the major producer. These

foundries produce tonnes of waste foundry sand causing various environmental hazards in the

society. Similar results being observed in Aurangabad region of Marathwada.

9

Typically, about 1 ton of foundry sand is required for each ton of iron or steel casting

produced. Thus, 3 to 5 metric tonnes of waste foundry sand is produced in India per year. This

waste foundry sand is dumped on an open ground, thus polluting the ground. Hence it is a

requirement of present era to minimize this pollution caused by foundry sand and similar by-

products generated from foundries.

1.4 Aggregate:

Concrete essentially consists of coarse and fine aggregates used for giving bulk to the

concrete. To increase the density of resulting mix, the aggregates are used in 2 sizes-

1.4.1 Fine aggregates:

It is an aggregate most of which passes through a 4.75 mm IS sieve and contains only so

much coarser material as is permitted by specifications. Sand is generally considered to have

size limit about 0.07mm. The fine aggregate may be one of the following types:

Natural sand the fine aggregate produced by natural disintegration of rock that has been

deposited by stream and glacial agencies.

Crushed stone sand i.e. the fine aggregate produced by crushing hard stone.

Crushed gravel sand i.e. the fine aggregate produced by crushing natural gravel.

1.4.2Coarse aggregates:

The aggregates most of which are retained on the 4.75 mm IS sieve and contains only so

much of fine material permitted by the specifications are termed as coarse aggregate. The coarse

aggregate may be one of the following types:

Crushed gravel or stone obtained by crushing gravel or hard stone

Uncrushed gravel or stone resulting from natural disintegration of rock

Partially crushed gravel or stone obtained as a product of blending of above two types

The graded coarse aggregate is described by its nominal size i.e. 40mm, 20mm, 16mm,

12.5mm etc. Natural sand from Godavari River confirming to IS 383-1970 [46] is used. Various

10

tests such as specific gravity, water absorption, impact strength, crushing strength, sieve analysis

etc. have been conducted on CA & FA to know their quality & grading. The above said test

results are shown in Tables (2) to (5). Crushed black trap basalt rock of aggregate size 20mm

down and 10mm down was used confirming to IS 383-1970.

1.5 Water:

Water is the most important and the least expensive ingredient in concrete. A part of

mixing water is utilized in hydration of cement to form binding matrix in which the aggregates

are held in suspension until the matrix are hardened. The remaining water acts as lubricant

between the fine and coarse aggregate and makes concrete workable.

Generally cement requires 3\10 of the weight for hydration. Hence the minimum water

cement ratio required is 0.35. Concrete containing water in this proportion will be harsh and may

not be workable. For the lubrication of the mix additional water is required and this additional

water must be kept to minimum such that it will not affect strength of concrete. The water used

for mixing and curing of concrete must be free from deleterious materials and dissolve salts.

Portable water is generally considered satisfactory for mixing concrete. [4]

Table 4: Effects of dissolved salts in water on compressive strength:

11

% of salt in water % reduction in compressive strength.

0.5 SO4 4

0.1 SO4 10

5 NaCl 30

CO2 20

The following impurities must not be present in water during mixing of concrete:

Suspended particles

In-organic salts such as salts of Manganese, Tin, Zinc, Copper, and Lead.

Acids and alkalis

Algae.

Sugar

The water must be free from oil contamination and salts.

CHAPTER 2 2.1 HISTORICAL DEVELOPMENT

2.1 Development of concrete:

12

2.1.1Concrete:

The name concrete comes from the Latin "concretus", which means to grow together. This is

a good name for this material, as the chemical hydration process, which mainly occurs over the

time scale of hours and days, causes the material to grow together from a viscoelastic, moldable

liquid into a hard, rigid solid. The Romans were the first to invent the hydraulic cement-based

concrete. They built numerous concrete structures, including the Pantheon in Rome, one of the

finest examples of Roman architecture that survives to this day, which has a 42-meter-diameter-

dome, made of poured concrete. The cement used mostly in today's concrete is called Portland

cement. The process to produce Portland cement was invented by Joseph Aspdin in the early

1800's in England. The name Portland may have been originally a marketing ploy, as Portland

building stone was very popular in England at that time .Cement is the powder that reacts with

water to form cement paste, a hard, solid material that forms the matrix for the concrete

composite. The addition of sand (fine aggregates), that is up to a few millimeters in diameter,

makes mortar, and the addition of rocks (coarse aggregates) of up to a few centimeters in

diameter makes concrete. It has always been known that concrete is a porous material, whose

properties depend on its pore space. There are many different kinds of pores in concrete, ranging

from the air voids that are entrapped in the mixing process, which can be quite large, up to a few

millimeters in diameter, to the capillary pores, which are essentially the space occupied by the

leftover water from mixing, down to the nanometer-scale pores that exist in some of the

hydration products produced by the cement-water chemical reaction. The focus has been on

concrete's compressive strength, which has been mainly related to the overall porosity of the

cement paste matrix and the amount and structure of the aggregates.

It is one of the most common materials used in the construction industry. In the past few

years, many research and modification has been done to produce concrete which has the desired

characteristics. Cementitious materials known as pozzolans are used as concrete constituents, in

addition to Portland cement. There is always a search for concrete with higher strength and

durability. In this matter, blended cement concrete with the incorporation of fibers has been

introduced to suit the current requirements. Plain concrete has good compressive strength but has

low tensile strength, low ductility and low fire resistance. To circumvent these shortcomings,

13

extensive research by concrete technologist has led them to find a very promising concrete

material called as fiber reinforced concrete.

2.1.2 Fiber Reinforced Concrete:

Fiber reinforced concrete can be defined as a composite material consisting of a cement

matrix containing uniformly or randomly dispersed discrete fibers. The fibers act as crack

arrestors that restrict the growth of cracks in the matrix, controlling them from enlarging which

under stress eventually causes brittle failure.

In the past, attempts have been made to impart improvement in tensile properties of

concrete members by way of using conventional reinforced steel bars and also by applying

restraining techniques. Although both these methods provide tensile strength to the concrete

members, they however, do not increase the inherent tensile strength of concrete itself.

It has been recognized that the addition of small, closely spaced and uniformly dispersed

fibers to concrete would act as crack arrester and would substantially improve its static and

dynamic properties. This type of concrete is known as Fiber Reinforced Concrete. Fiber is a

small piece of reinforcing material possessing certain characteristic properties. They can be

circular or flat. The fiber is often described by a convenient parameter called “aspect ratio”. The

aspect ratio of the Fiber is the ratio of its length to its diameter. Typical aspect ratio ranges from

30 to 150. [7]

2.1.3 Used Foundry Sand in Cement Mortars and Concrete Production:

Used foundry sands represent the highest amount of solid wastes generated by foundries.

Classified by European Union regulations as non hazardous waste, they represent a relevant

source to be reused in several industrial sectors, in building construction primarily.

In present paper, the properties of mortars and concretes containing different dosages of

used foundry sand (UFS) as partial replacement of sand were investigated in both fresh and

hardened conditions. In particular, higher percentages of addition, but lower if referred to the

14

whole aggregate (fine and coarse), were considered in concretes than in mortars. Both mortars

and concretes were evaluated with respect to consistency of the fresh mixture and compressive

strength of the hardened material. Elastic modulus determination of the hardened material was

carried out on concretes. A low (10%) amount of used foundry sand does not change the

mortar‘s performances. In the presence of higher additions a workability decreasing can be

outlined, and then a higher dosage of super plasticizer is required in order to keep it constant.

Mechanical performances lower of about 20-30% than those of the conglomerate without used

foundry sand are observed. The higher penalization it seems to concern to the conglomerates of

better quality (i.e. lower water-cement ratio).

2.1.4 Agricultural Reuse of Foundry Sand:

BILLIE J. LINDSAY and TERRY J. LOGAN found that foundries continually generate

large quantities of excess sand that has the potential to be beneficially reused outside of the

foundry industry with only about 10% of the total reused primarily for construction purposes.

Potential agricultural applications reviewed are as an in situ addition to agricultural soils, use in

greenhouse potting or container mixes, as an ingredient in topsoil blends used for landscaping or

reclamation purposes, or in rooting zones for sports turf applications. Several studies focused on

risk assessment and regulatory guidelines. Use of foundry sand was compared to more

commonly used materials like native soil, and composted yard waste. [11]

.

CHAPTER 3 3.1 PERFORMANCE ANALYSIS

3.1.1Cement:

15

Table 5: Physical Properties of Cement. (Confirming to IS 12269 – 1987):

Sr. No. Description of Test Results

01 Fineness of cement (residue on IS sieve No. 9) 3 %

02 Specific gravity 3.15

03 Standard consistency of cement 29 %

04

Setting time of cement

a) Initial setting time

b) Final setting time

135 minute

288 minute

05 Soundness test of cement (with Le-Chatelier’s mould) 1.5mm

06

Compressive strength of cement:

a) 7 days

b) 28 days

57.8 N/mm2

79.5 N/mm2

3.1.2 Foundry sand:

16

Table 6: Physical properties of waste foundry sand and natural sand:

Properties Natural sand Foundry sand

Specific Gravity 2.64 2.6

Fineness Modules 2.53 2.33

Water absorption (%) 1.2 0.42

Moisture content (%) 0.16 0.11

Material finer than 75 l (%) 0.5 8

Clay lumps and friable particles(

%)

– 0.8

3.1.3 Aggregates:

Table7: Physical Properties of Fine Aggregate (sand):

Sr. No Property Results

1. Particle Shape, Size Round, 4.75mm down

2. Fineness Modulus 3.17

3. Silt Content 2%

4. Specific Gravity 2.63

5. Bulking of Sand 4.16%

6. Bulk Density 1793 Kg/m3

7. Surface Moisture Nil

Table 8: Physical Properties of Coarse Aggregate (20mm)

17

Sr. No Property Results

1. Particle Shape, Size Angular, 20mm,10mm down

2. Fineness Modulus of 20mm aggregates 7.4

3. Fineness Modulus of 10mm aggregates 6.87

4. Specific Gravity 2.77

5. Water Absorption 1.02%

6. Bulk density of 20mm aggregates 1603 Kg/ mm3

7. Bulk density of 10mm aggregates 1585 Kg/mm3

8 Surface Moisture Nil

3.1.4 Test on material:

Table 9: Sieve Analysis of Natural sand:

.

Sieve Aperture Retained(g) Retained (%) Cumulative

Retained (%)

Cumulative

Passing (%)

10mm 0 0 0 100

4.75mm 23.2 2 2 98

2.36mm 116.6 12 14 86

1.18mm 51.9 5 19 81

600 μm 113.3 11 31 70

300 μm 588.9 59 89 11

150 μm 85.6 9 98 2

75 μm 20.5 2 0 0

Total=1000 Total=253

Fineness modulus=253\100=2.53

18

Table 10: Sieve Analysis of 20 mm Coarse Aggregates:

Sr.

No.Sieve size

Weight

retained (kg)

Cumulative

weight

retained

% cumulative

weight

retained

% passing

01 80mm 0 0 0 100

02 40mm 0 0 0 100

03 20mm 6 6 40 60

04 4.75mm 5 11 73.3 26.7

05 2.36mm 4 15 100 0

06 1.18mm - - 100 0

07 600 µ - - 100 0

08 300 µ - - 100 0

09 150 µ - - 100 0

Total = 15 713.3

Fineness modulus= 713.33\100=7.133

19

Table 11: Sieve Analysis of foundry sand:

Sieve Aperture Weight

Retained(kg)

Cumulative

Retained

weight

Cumulative

Retained

weight (%)

Cumulative

Passing (%)

10mm

4.75mm 0.004 4 0.4 99.6

2.36mm 0.029 33 3.3 96.7

1.18mm 0.031 64 6.4 93.6

600 μm 0.488 552 55.2 44.8

300 μm 0.222 774 77.4 22.6

150 μm 0.132 906 90.6 9.4

Pan 0.94 1000 0 0

Total=1 Total=233.3

Fineness modulus=233.3\100=2.333

3.2 Preparations of Specimen:

1. Measurement of ingredients:

20

All cement, sand (natural or foundry), and coarse aggregate 20mm and 10mm

respectively are measured with the Digital balance. The water is measured with measuring

cylinder of capacity 1 liter and measuring jars of capacity 1000ml.

2. Mixing of concrete:

The ingredients were thoroughly mixed over the floor after sprinkling it with water. The

sand, cement and aggregate were measured accurately with equal mix design proportion, and

were mixed in dry state for normal concrete. The dry concrete mix was then thoroughly and

uniformly mixed till uniform and homogeneous mixing of all the ingredients in dry mix was

observed. The designed quantity of water was then added gradually to the dry mix so that it

gives a plastic mix of the required workability and w/c ratio. According to the specifications the

mix was turned 3 times so that the uniform concrete was obtained.

3 .Workability of concrete:

At every batch of mixing the concrete slump is measured and recorded with slump cone

apparatus as per relevant IS. Workability is measured in terms of slump.

4. Placing of concrete:

The fresh concrete was placed in the moulds by trowel. It was ensured that the

representative volume was filled evenly in all the specimens to avoid segregation, accumulation

of aggregates etc. Before placing concrete, the moulds are cleaned and oiled from inside for

smooth remolding. Concrete is mixed thoroughly and placed in the mould in three layers and

compacted by electrically operated Table vibrator with suitable fixing frame. It is vibrated till

concrete woes out of the mould. The vibration is continued till cement slurry just ooze out on

surface of moulds. Care is taken of cement slurry not to spill over, due to vibration and

segregation.

While placing concretes, the compaction in vertical position was given with the help of

tamping rod to avoid gaps in moulds.

5. Finishing of concrete:

21

After removing from vibrating table, the moulds were kept on ground for finishing and

covering up for any leftover position. The concrete is worked with trowel to give uniform

surface.

Care is taken not to add any extra cement, water or cement mortar for achieving good

surface finish. The additional concrete is chopped off from top surface of the mould for avoiding

over sizes etc. Identification marks are given on the specimens by embossing over the surface

after initial drying.

6. Demoulding and curing of specimens:

The plain cement concrete specimens are demoulded carefully after 24 hours of casting

wet concrete and kept in water tank for curing of 28 days.

3.3 Details of Test Specimens for Tests on Hardened Concrete:

The specimens used were cubes, cylinder and beam. Dimensions of each test specimen

are as under:

Cube: 150mmx150mmx150mm.

Beam:700mmx150mmx150mm

Cylinders: 150mm (diameter) x 300mm (height)

Beam specimens were used to determine flexural strength, and equivalent compressive

strength.

Cubes were used to find the compressive strength.

Cylinders were used to determine the split tensile strength.

3.4 Testing of concrete specimens:

1. Cube specimen:

1. At first the cube is placed properly at the centre in between the two plates of Digital

Compression Testing Machine (DCTM).

2. For the application of the load, the load release valve is tightened in clockwise direction.

3. A gear is provided, to control the speed of loading.

4. When the gradual load is applied on the concrete cube specimen, a point comes when there is

a failure of cube specimen. The digital indicator provided at the top of the DCTM machine

indicates the peak load and peak stress in Mpa.

22

5. After the failure the valve is released in anticlockwise direction.

6. The specimen is kept aside for the further requirements.

2. Cylinder specimen:

1. Firstly mark the centers of cylinders on the top and bottom face of cylinder.

2. Place the cylinder on movable cross head in the transverse direction. For applying point load

to the cylinder, place two bars one exactly above the marked center of cylinder and one exactly

below the marked centers of the cylinder.

3. After this experimental setup switch on the UTM machine.

4. With the help of range regulator arrange the movable frame and movable cross head, with

above experimental setup of cylinder in required height.

5. Now for applying the load, tight load regulator in clock wise direction.

6. After applying load gradually, on the cylinder a point comes when the cylinder fails, at that

point digital indicator shows peak load and peak values.

Release the load regulator in anti-clock wise direction.

3. Beam specimen:

1. Firstly mark the markings from both ends of the beam at 20cm distance on top of the beam.

2. Now, place the beam on movable cross head such that the marked ends should be exactly on

the two ends of the movable cross head.

3. After this experimental setup switch on the UTM machine.

4. With the help of range regulator arrange the movable frame and movable cross head, with

above experimental setup of beam in required height.

5. Now for applying the load, tight load regulator in clock wise direction

6. After applying load gradually, on the cylinder a point comes when the beam fails at that point

digital indicator shows peak load and peak stress values.

7. Release the load regulator in anti-clock wise direction.

3.5 Compressive test on concrete:

Compressive strength test on cube:

23

A cube compression test was performed on standard cubes of size 150x150x150 after 28

days of immersion in water for curing. The compressive strength of specimen was calculated by

the following formula:

fcu = Pc /A

where,

Pc = Failure load in compression, KN

A = Loaded area of cube, mm2

Table 12: Compressive Strength Test on Cube (150mm x 150mm):

SR NO FOUNDRY SAND (M20) NATURAL SAND (M20)

STRESS

(Mpa)

AVG

(Mpa)

STRESS

(Mpa)AVG(Mpa)

1. 18.5

21.56

54

46.932. 23 54.4

3. 23.2 32.4

Table13: Compressive Strength Test on Cube (150mm x 150mm):

SR NO FOUNDRY SAND (M30) NATURAL SAND (M30)

STRESS

(MPa) AVG

(MPa)

STRESS

(MPa)

AVG

(Mpa)

1. 40.8

37.267

37.5

57.032. 37.9 62.7

3. 33.1 70.9

24

18 20 22 24 26 28 30 320

10

20

30

40

50

60

COMPRESSIVE STRENGTH

foundrynatural

GRADE OF CONCRETE

STR

ESS

(MP

a)

Fig 1: Comparison between Compressive Strength of Natural and Foundry Sand

3.6 Split Tensile Test on cylinder:

The split tensile test is well known indirect test used to determine the tensile strength of

concrete. Due to difficulties involved in conducting the direct tension test, a number of indirect

methods have been developed to determine the tensile strength of concrete. In these tests, in

general a compressive force is applied to a concrete specimen in such a way that the specimen

fails due to tensile stresses induced in the specimen.

25

P

150mm diameter concrete cylinder

Cylinder Split Tensile Test Setup:

The tensile strength at which failure occurs is the tensile strength of concrete. In this

investigation, the test is carried out on cylinder by splitting along its middle plane parallel to the

edges by applying the compressive load to opposite edges. The arrangement for the test is shown

in photo with the pattern of failure. The split tensile strength of cylinder is calculated by the

following formula.

ft = 2Pl /LD

where,

ft = Tensile strength, MPa

Pl = Load at failure, N

L = Length of cylinder, mm

D = Diameter of cylinder, mm

26

Table 14: Split Tensile Strength on Concrete Cylinder:

SR NO FOUNDRY SAND (M20) NATURAL SAND (M20)

STRESS

(MPa) AVG (Mpa)

STRESS

(MPa) AVG(Mpa)

1. 1.92

1.997

2.40

2.4962. 2.12 2.65

3. 1.952 2.44

Table 15: Silt Tensile strength on concrete cylinder:

SR NO FOUNDRY SAND (M30) NATURAL SAND (M30)

STRESS

(MPa)

AVG(Mpa) STRESS

(MPa)

AVG(Mpa)

1. 2.144

2.285

2.68

2.8562. 2.344 2.93

3. 2.368 2.96

18 20 22 24 26 28 30 320

0.5

1

1.5

2

2.5

3

SPLIT TENSILE STRENGTH

foundrynatural

GRADE CONCRETE

STR

ES

(MP

a)

Fig: 2 Comparison between Split Tensile Strength of Natural and Foundry Sand

27

3.7 Flexural strength on concrete:

Standard beams of size 700 x 150 x 150mm were supported symmetrically over a span of

400mm and subjected two points loading till failure of the specimen. The deflection at the center

of the beam is measured with sensitive dial gauge on UTM. The two broken pieces (prisms) of

flexure test were further used for equivalent cube compressive strength.

Two Point Loading Setup in Flexure Test

(All Dimensions are in mm)

The flexural strength was determined by the formula

= Pf L / bd2

Where,

= Flexural strength, MPa

Pf = Central load through two point loading system, N

L = Span of beam, mm

b = Width of beam, mm

d = Depth of beam, mm

28

Table 16: Flexure Strength Test On Beam

SR NO FOUNDRY SAND (M20) NATURAL SAND (M20)

STRESS

(MPa) AVG(Mpa)

STRESS

(MPa) AVG(Mpa)

1. 4.176

4.425

4.64

4.9162. 4.464 4.96

3. 4.635 5.15

Table 17: Flexure Strength Test On Beam

SR NO FOUNDRY SAND (M30) NATURAL SAND (M30)

STRESS

(MPa)

AVG(Mpa) STRESS

(MPa)

AVG(Mpa)

1. 4.824

5.502

5.36

6.1132. 5.544 6.16

3. 6.138 6.82

29

18 20 22 24 26 28 30 320

1

2

3

4

5

6

7

FLEXURAL STRENGTH

foundrynatural

MIX CONCRETE

STRE

SS (M

Pa)

Fig: 3 Comparison between Flexural Strength of Natural and Foundry Sand

30

CHAPTER 4 CONCLUSION

The key motivating factor for reusing foundry sand is cost savings. Without reuse,

foundries must pay for disposal of their sand.

As it is true for any recycling opportunity, the success of recycling of spent foundry sand is

dependent upon economics - the issues will be cost, availability of supply, and consistent quality

of the feedstock. The Successful resolution of these issues will enable not only to keep spent

foundry sand out of the landfill, but also to increase the competitiveness of both the foundries.

Further conclusions after performing experiments were

The water content required for the foundry sand was more than that of the natural.

The Compressive, Split Tensile and the Flexural strength of foundry is less than that of

natural sand when mixed completely in replacement of it.

As the water absorption content is high as compared to the natural sand it directly affects

the workability of concrete mix.

Concrete can be produced using discarded foundry sands as a partial replacement of

regular concrete sand, about 25% to 30% of discarded foundry sand may be used with the

proper admixtures to the concrete for obtaining the desired strength.

5. Future scope:

The research carried out so far is only the initial stage of this project. Durability studies have

not been done on concrete containing used foundry sand. Therefore the durability properties like

alkali-silica reaction, freeze-thaw, chloride ion permeability, interaction with air-entraining

agents, fatigue strength, etc., of concrete made with used foundry sand concrete, can be

experimented. The present project has a wide future scope in experimenting the foundry sand

with its partial replacement in the concrete.

31

CHAPTER-5 REFERENCES

1. Winkler E, Bol’shakov AA. Characterization of foundry sand waste. Chelsea Center for

Recycling and Economic Development, University of Massachusetts; 2000 Report nr 31.

2. I.S 516-1987,”Method of Test for Strength of Concrete”,Bureau of Indian Standard ,New

Deldi,1988.

3. I.S.10262-1982,”Indian Standard Recommended Guidelines for Concrete Mix Design”,Bureau

of Indian Standard,New Delhi,1983

4. Shetty M.S,”Concrete Technology,Theory and Practise”,S.Chand and compony Ltd,New

Dehli,2003.

5. Foundry Sand For Engineers, (80 pp, 265K, about PDF) – Federal Highway Administration’s

report providing technical information about the potential civil engineering applications of

foundry sand

6. Foundry Sand – Chapter in the Federal Highway Administration’s,” User Guidelines for

Waste and Byproduct Materials in Pavement Construction “

7. Job Thomas and Ananth Ramaswamy,”Mechanical Properties of Steel Fiber-Reinforced

Concrete,”Journal of Materials in Civil Engineering , Vol 19, no.5, May1, 2007, pp.385-389.

8. Grover, Jennifer E., Bob Drake, and Steven Prokopy. "100 Years of Rock Products, History of

an Industry: 1896-1996." Rock Products, July 1996, pp. 29.

9. Mack, Walter N. and Elizabeth A. Leistikow. "Sands of the World." Scientific American,

August 1996, pp. 62-67.

10. Miller, Russell V. "Changes in Construction Aggregate Availability in Major Urban Areas of

California Between the Early 1980s and the Early 1990s." California Geology, January/February

1997, pp. 3-17.

11. Saveria Monosi, Daniela Sani and Francesca Tittarelli, “Used Foundry Sand in Cement

Mortars and Concrete Production”, The Open Waste Management Journal, 2010, 3, 18-25.

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