Field of Invention:

The present invention relate to the field of construction material. In particular, the Invention provides a composition based on graded sand granules and its method of preparation.

Background of the Invention:

The development of concrete technology in the world has entered a new era, better known as
the era of smart concrete, which in this era of nanotechnology to trigger the development of the existing concrete technology, The development of nanotechnology in the produced concrete with very high quality and high durability of concrete known as nano concrete. The understanding of nano includes a material that has the physical properties, chemistry, and biology that can change dramatically when the dimensions of the material into the nanometer scale {particle size (1 to 100) nm}. The manufacture of concrete with concrete nanotechnology is intended to be denser and reduce the amount of pores contained in the concrete. The illustration of the concept of nanotechnology in concrete construction is shown in Fig. 1.
Sand is an important construction material of natural origin. Mixed with cement and lime, millions of tons of sand are used every month for construction as mortar, plasters and concrete.
The sand consist of natural sand, crushed stone sand or crushed gravel sand or a combination of any of these. The sand shall be hard, durable, clean and free from adherent coatings and organic matter and shall not contain the amount of clay, silt and fine dust more. The term sand is used for rock particles that range in grain size between 2mm and l/16mm. In composition, they are predominantly an oxide of silica (Si02).Mineralogical, they consist mostly broken grains of mineral Quartz (Si02) produced as a result of breakdown of granites, sandstone and similar rocks by natural processes of weathering and erosion.
Construction sand is used for mortar and masonry work. Construction sand is using in various
works, these materials are used for the construction of infrastructures like housing, road
works, railway works, irrigation works, dam works, bridgeworks and other construction
works.
Sand is really one of the most important construction materials. If we consider (1:2:4)
proportion cement concrete work by its volume, the percentage of sand in totality is
2/(1+2+4) 100=28.57.Thus, the role of construction sand would be more than 28%.

In building industry, construction material is procured from various sources like Natural resources (e.g. sand, aggregate etc.) and Industrial resources (e.g. cement etc.). Natural resource procurement is still an almost unorganized sector in India which causes least control on quality and quantity both. Since plastering and concreting is mostly associated with this factor, its quality and cost depends on so many direct and indirect issues, for constructional work require the characteristics of aggregates are: (1) strength (2) size (3) Particle shape (4) Surface texture (5) Grading (6) Impermeability (7) cleanliness (8) chemical inertness (9) Physical and chemical stability at high temperatures (10) coefficient of thermal expansion . These factors can properly be checked and controlled in lab.
The use of alternative aggregate like silica sand is a natural step in solving part of depletion of natural aggregates. The investigation on alternative material for concrete making started before half a century.
Each year thousands of tons of waste materials are disposed on the valuable land which results in the occupation and degradation of valuable land. Decreasing of natural resources is a common phenomenon in developing countries like India due to rapid urbanization & industrialization involving construction of infrastructures.
Hence, there is requirement of reusing the waste material disposed on the valuable lands and providing a quality alternative material for constructional work.
Objective of the invention;
Primary object of the invention is to overcome the drawback associated with prior arts.
Another object of the present invention is to provide graded sand as construction materials
and its supply management in the construction works.
Yet another object of the present invention is to provide a quality product for construction
industry.
Yet another object of the present invention is to provide a cost effective constructional
product.
Yet another object of the present invention is to provide time saving constructional product
for constructional industry.
Yet another object of the present invention is to convert the unorganized material
procurement system to organized one.

Yet another object of the present invention is to provide a new product which is combination of selected and tested quality graded sand and silica in engineered proportion - provides safe, efficient, engineered quality product in packed and organized way.
Summary of the Invention;
The present invention provides a method of reusing the waste constructional material and obtaining the graded sand from it and provide a composition for structural concrete of M-20. In an aspect of the present invention, there is provided a method for obtaining graded sand particle composition from the waste of building construction. The method comprises the steps of:
a) Obtaining the silica sand from raw material;
b) Washing the sand obtained from step (a) and separating the clay material from said raw material;
c) Sieving the sand obtained from step (b) and collecting sand of different size
where said size comprises 4.75 mm, 2.36 mm, 1.18 mm, 600 urn, 300 urn, 150
urn, 75 urn, 30 mesh to 80 mesh;
d) Mixing the sand resulting from step (c) with natural fine aggregate and water;
e) Optionally, using the different graded sand for desirable purpose.
In an aspect of the present invention, there is provided a composition for structural concrete of M-20. The graded silica sand particle composition comprises graded silica sand present in an amount ranging from 0% to 70% while the presence of natural fine aggregate and water varies in the ratio ranging from 0.50 to 0.45.
Detailed description of Drawing;
To further clarify advantages and features of the present invention, a more particular
description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings in which:
Figure 1: illustrates the constructional nano material for filling pores.
Figure 2: illustrates top view of sieve for of obtaining graded silica in an accordance to an embodiment of the invention

Figure 3: illustrates side view of sieve for of obtaining graded silica in an accordance to an embodiment of the invention
Figure 4: illustrates chemical structure of silica sand.
Detailed description of invention;
For the purpose of promoting an understanding of the principles of the invention,
reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof. Throughout the patent specification, a convention employed is that in the appended drawings, like numerals denote like components.
The present invention provides a method of reusing the waste constructional material and obtaining the graded sand particle from it. The Invention also provides composition for structural concrete of M-20.
In an embodiment, the graded silica sand particle composition comprises following components:
graded silica sand present in an amount ranging from 0% to 70% while natural fine aggregate and water varies in the ratio ranging from 0.50 to 0.45.
In an embodiment, the silica sand particle corresponds to structural concrete of M-20. In an embodiment, the graded size obtained from sieves size of 4.75 mm, 2.36 mm, 1.18 mm, 600 urn, 300 urn, 150 urn, 75um, 30 mesh to 80 mesh.
In an embodiment, the graded silica sand composition comprises slump of approximately 25.81%.
In another aspect, the Invention provides a method for obtaining graded sand from the waste of building construction.
In an embodiment, the method comprises following steps: a) Obtaining the silica sand from raw material;

b) Washing the sand obtained from step (a) and separating the clay material from
said raw material;
c) Sieving the sand obtained from step (b) and collecting sand of different size
where said size comprises 4.75 mm, 2.36 mm, 1.18 mm, 600 urn, 300 urn, 150
urn, 75 urn, 30 mesh to 80 mesh;
d) Mixing the sand resulting from step (c) with natural fine aggregate and water;
e) Optionally, using the different graded sand for desirable purpose.
In an embodiment, the silica sand has different size/s that are obtained from different sieves size ( Fig 1 and Fig 2 ) having 4.75 mm, 2.36 mm, 1.18 mm, 600 urn, 300 urn, 150 urn and 75 urn in size.
In an embodiment, obtained Sand size of 30 mesh to 80 mesh (500 micron) is used in the glass industries.
In an embodiment, the Sand size has 1.18mm to 600 micron that can be used in making concrete mix as the partial replacement of fine aggregate.
In an embodiment, the Silica sand is obtained from the raw material (locally available in mamuara village in Kutch district). After washing the raw material, the silica sand is separated by sieve size 1. 18mm of raw material. Raw material is washed for taking out the clay material which is useful in making the tiles. In the raw material about 10% is clay which is supplied to the ceramic factories.
Another aspect of the present invention provides the composition for structural concrete of M-20.
In an embodiment, the composition comprises the replacement of fine aggregate by graded silica sand in a percentage of 0 % to 70% with the natural fine aggregate and water with ratio of0.50to0.45.
The percentage replacement will be 0%, 10%, 20%, 30%, 40%, 50%, 60% and 70% with natural fine aggregates.
In an embodiment, the replacement of silica sand increases slump from 4.84 % to 25.81%. In an embodiment the replacement of silica sand in concrete the compressive strength increases 0.22% at 50% replacement.
In an embodiment replacement of silica sand increases 0% to 70% and slump increases from 3.64% to 23.63%.
In an embodiment the replacement of silica sand in concrete, the compressive strength compressive strength increases 1.21% at 50% replacement.

In an embodiment for concrete construction, OPC-53 grade cement is used. Cubes, beams
and cylinders will be casted and tested compressive strength, Split tensile strength, and
flexural strength as well as for durability properties. Optimum replacement of silica sand can
be used in structural concrete.
In an embodiment different size of silica sand are separated from the obtained raw material
by different size of sieve. Sand size of 30 mesh to 80 mesh (500 micron) is used in the glass
industries. Sand size 1.18mm to 600 micron can be used in making concrete mix as the partial
replacement of fine aggregate. Nearly about 200 tones of silica sand is obtained daily after
washing the raw material. Sometimes it is used in the glass factories otherwise they dump
them back into the mines.
In an embodiment, the mix proportion for M 20 with W/C ratio of 0.50 as mix - 1 & M 20
with W/C ratio of 0.45 as mix - 2 was casted. Slump test was tested when the concrete in
fresh concrete.
In an embodiment the replacement of silica sand in concrete, the compressive strength was
decreases up to 30% replacement and then increases up to 50% replacement after starts
decreasing up to 70% replacement, compressive strength was increases 0.22% at 50%
replacement compares to normal concrete for mix - 1.
In an embodiment, Flexural strength decreases from 2.54% to 16.57% as the replacement
percentage of silica sand increases for mix - 1.
In an embodiment, Split tensile strength decreases from 5.39% to 19.78% as the replacement
percentage of silica sand increases for mix - 1.
In an embodiment , the percentage of replacement of silica sand was increases 0% to 70%
slump is increases from 3.64 % to 23.63% for mix - 2.
In an embodiment, the replacement of silica sand in concrete, the compressive strength was
decreases up to 30% replacement and then increases up to 50% replacement after starts
decreasing up to 70% replacement, compressive strength was increases 1.21% at 50%
replacement compares to normal concrete for mix - 2
In an embodiment, Flexural strength decreases from 3.29% to 19.78 % as the replacement
percentage of silica sand increases for mix - 2.
In an embodiment Split tensile strength decreases from 1.98% to 15.84% as the replacement
percentage of silica sand increases for mix - 2.
In an embodiment, Replacement of silica sand in concrete increases from 10% to 70%, the
acid cured cube strength was decreases from 4.54% to 20% for mix - 1. For mix -2 the acid
cured cube strength was decreases from 6.03% to 16.66%

In an embodiment, Replacement of silica sand in concrete increases from 10% to 70%, the
sulphate cured cube strength was decreases from 3.62% to 28.03% for mix - 1. For mix -2
the sulphate cured cube strength was decreases from 2.08% to 14.57%
In an embodiment 50% replacement of silica sand concrete gives best result amongst other
replacement of silica sand.
The current invention grades the coarse sand in 3 sizes, hence the wastage of coarse sand can
be avoided, since different sizes of coarse sand will be reused for specific purposes.
Further the Invention can be explained with the non limiting example.
Example 1:
Silica is a very fine material composed solely of Silicon and Oxygen, the two most abundant
elements in the earth's crust. Silica is hard, chemically inert and has a high melting point,
attributable to the strength of the bonds between the atoms. Silica sand is not flammable,
combustible or explosive. It is not known to be toxic. It is not known to be an environmental
hazard. Silica sand is insoluble in water. Silica sand should be kept dry and out of the
element.
The chemical formula of silica sand is Si02. The chemical composition of silica sand is Fig
4.
Example 2:
Sieve analysis of Silica sand 1:
The locally available silica sand used as partial replacement of fine aggregate. The properties
of silica sand were determined by conducting tests as per IS 2386 (Part-1). The sieve analysis
is conducted to determine the particle size distribution of silica sand. The different sieves
sizes used for sieve analysis of silica sand was 4.75 mm, 2.36 mm, 1.18 mm, 600 urn, 300
urn, 150 urn and 75 urn. Sieve analysis result is given in table.
Table - 1

Sieve analysis of silica sand Sieve size (mm) Weight retain (gms) Cumulative weight retain (gms) Cumulative percentage weight retain (%) Cumulative percentage weight passing
10 0 0 0 100
4.75 2 2 0.1 99.9
2.36 14 16 0.8 99.2
1.18 146 160 8.1 91.9
600 micron 846 1002 50.4 49.6
300 micron 948 1950 97.4 2.2
150 micron 28 1978 99.2 0.8

Example 3;
Physical properties of silica sand
The below table shows following properties:
Table - 2

Physical properties of silica sand Gradation Fall in Zone I
Moisture content 1.4%
Fine modulus 2.56
Silt content 0.78%
Example 4;

Specific Gravity of silica sand Description Value
1 Weight of pcynometer (Wl) gms 675
2 Weight of Water + soil (W2) gms 875
3 Weight of water + pcynometer + soil (W3) gms 1568
4 Weight of pcynometer + water (W4) gms 1445
5 Apparent Specific Gravity =W2-W1/((W4-W1)-(W3-W2)) 2.60
The increase in strength is attributed due to the formation of Tri calcium silica hydrate (C3SH) due to reaction between the silica in silica sand and calcium hydroxide Ca(OH)2 present in the cement. This is a double reaction as C-S-H is already formed in hydration of cement which is a characteristic of pozzulonic materials. This the main cause for the increase in compressive strength. The flexural and tensile strength is not affected even at reduced cement content in the mix at different percentages of replacement indicating the significant strength characteristic of silica sand.

WE Claim:

1. A graded silica sand particle composition comprising graded silica sand present in an amount ranging from 0% to 70% while natural fine aggregate and water varies in the ratio ranging from 0.50 to 0.45.
2. The silica sand particle composition as claimed in claim 1, wherein said particle corresponds to structural concrete of M-20.
3. The graded silica sand composition as claimed in claim 1, wherein the graded size obtained from sieves size of 4.75 mm, 2.36 mm, 1.18 mm, 600 urn, 300 urn, 150 urn, 75um, 30 mesh to 80 mesh.
4. The graded silica sand composition as claimed in claim 1, comprises slump of approximately 25.81%.
5. A method for obtaining a graded silica sand particle composition as claimed in claim 1, comprising the step/s of:

a) Obtaining the silica sand from raw material;
b) Washing the sand obtained from step (a) and separating the clay material from said raw material;
c) Sieving the sand obtained from step (b) and collecting sand of different size
where said size comprises 4.75 mm, 2.36 mm, 1.18 mm, 600 urn, 300 urn, 150
urn, 75 urn, 30 mesh to 80 mesh;
d) Mixing the sand resulting from step (c) with natural fine aggregate and water;
e) Optionally, using the different graded sand for desirable purpose.