FORM-2
THE PATENT ACT,1970
(39 OF 1970)
AND
THE PATENT RULES, 2003
(As Amended)
COMPLETE SPECIFICATION (See section 10;rule 13)
"MANUFACTURING OF PRE-STRESSED CONCRETE POLE USING BOTTOM ASH BY PARTIAL REPLACEMENT OF FINE
AGGREGATES"
Tata Power Company Limited, a corporation organized and existing under the laws of India, of Station - A, Trombay Thermal Power Plant, Chembur, Mumbai - 400074, India.
The following specification particularly describes the invention and the manner in which it is to be performed:

MANUFACTURING OF PRE-STRESSED CONCRETE POLE USING BOTTOM ASH BY PARTIAL REPLACEMENT OF FINE AGGREGATES
TECHNICAL FIELD
This invention relates to re-use of waste material in industrial process for useful construction applications, more specifically, the invention relates to manufacturing of pre-stressed concrete electric pole using bottom ash by partial replacement of fine aggregates, where bottom ash is a by-product in thermal power plants that use coal as the fuel.
BACKGROUND
Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced in prior art.
In the current scenario, there are multiple thermal power plants that operate in various parts of the country for the purpose of generating electricity. In this context, coal happens to be one of the major fuels used in thermal power plants in addition to natural gas and petroleum gas. Here, bottom ash is a resultant by-product in thermal power plants where coal is used as the primary fuel, and this bottom ash is categorized as waste that needs to be disposed in a remote disposal area. Due to the physical properties and nature of bottom ash, chemical properties like presence of heavy metals, requires careful handling. It is either disposed to land filling with all probable treatment based on the strict guidelines of pollution control board or identifying a use in any civil engineering application.
In addition, disposal of bottom ash may further complicate things as bottom ash includes soluble chemicals which may pollute underground water bodies, which are a common mode of supply of water for numerous people that live near the disposal area of bottom ash. Furthermore, such kinds of bottom ash handling

constrain the smooth operation of the thermal plant and increases maintenance expenses in the plant. This gives opportunity for researchers to identify how to make best use of the bottom ash. In this context, overhead electric poles are constructed in large numbers across the country. Mostly such electric poles are constructed using concrete and sand as the main components in the composition. However, the availability of sand has also been a problem that the country has been facing. Multiple research projects were done to identify a complete or partial replacement for the usage of sand.
Therefore, there is a need to find an alternative for extensive use of sand in the construction of electric poles and to effectively re-use residual bottom ash to gain returns from the maintenance expenses of the thermal plant and to improve smooth handling of the thermal plant.
SUMMARY
The following presents a simplified summary of the subject matter in order to provide a basic understanding of some aspects of subject matter embodiments. This summary is not an extensive overview of the subject matter. It is not intended to identify key/critical elements of the embodiments or to delineate the scope of the subject matter. Its sole purpose is to present some concepts of the subject matter in a simplified form as a prelude to the more detailed description that is presented later.
A pre-stressed concrete electric pole disclosed here addresses the need for an alternative for extensive use of sand in the construction of electric poles and to effectively re-use residual bottom ash to gain returns from the maintenance expenses of the thermal plant and to improve smooth handling of the thermal plant. The pre-stressed pole (or the pre-stressed concrete electric pole) involves usage of bottom ash a fine aggregate, wherein the generic use of aggregates, for example, sand which is used as the raw material along with concrete in the manufacturing of pole is replaced partly, for example, 50% by using bottom ash.

The technical and physical parameters of this pre-stressed bottom ash concrete pole also match with conventional concrete pole in all respect. This will help in addressing the issue of bottom ash handling/disposal across different industries where bottom ash is generated as a waste product, especially in thermal power plants.
As used herein, the term “M40” refers to a grade of concrete, more specifically, M40 grade stands for it's a mix of concrete with a characteristic compressive strength of 40 N/mm2.
The following are the steps involved in the making of pre-stressed bottom ash concrete pole:
1. Concrete mix design: concrete mix has been designed to get targeted strength of M40 grade concrete wherein fine aggregate (sand), one of the raw materials of concrete for manufacturing of pole is replaced partly (50%) by bottom ash.
2. Trial cube testing – various composition of bottom ash with sand were tried and finally, it was concluded to replace sand by 50% with bottom ash to get targeted strength of M40 grade concrete.
3. Form work: necessary form work of M S sheet was fabricated as per the drawing for casting of pole.
4. Pre-tensioning and casting – necessary pre tensioning of 175 kg/sq.mm to wires was introduced and poles were casted.
5. Cutting of tendons and de-shutting: the pre tensioned wires were cut after 28 days and shuttering was removed.
6. Installation – The pole is ready for installation after 28 days of curing.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The foregoing and further objects, features, and advantages of the present subject matter will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings, wherein numerals are used to represent like elements.

It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter, and are, therefore, not to be considered for limiting of its scope, for the subject matter may admit to other equally effective embodiments.
FIGURE 1A illustrates a mixing design for the pre-stressed pole, as an example embodiment of the present disclosure.
FIGURE 1B illustrates a trial cube testing for the pre-stressed pole, as an example embodiment of the present disclosure.
FIGURE 1C illustrates a form work for the pre-stressed pole, as an example embodiment of the present disclosure.
FIGURE 1D illustrates a pre-tensioning and casting for the pre-stressed pole, as an example embodiment of the present disclosure.
FIGURE 1E illustrates cutting tendons and de-shutting for the pre-stressed pole, where the pre-stressed pole is ready for installation, as an example embodiment of the present disclosure.
FIGURE 2 illustrates a front view of the pre-stressed pole after installation, as an example embodiment of the present disclosure.
FIGURE 3A illustrates a test report of the concrete mix design used in the pre-stressed pole.
FIGURE 3B illustrates a test report based on a trial mix design of the concrete mix that is used in the pre-stressed pole.

FIGURE 3C illustrates a test report based on mechanical testing performed for crushing strength of the concrete mix that is used in the pre-stressed pole.
FIGURE 3D illustrates a test report based on mechanical testing performed for consistency, fineness, setting time, compressive strength, and specific gravity of the concrete mix used in the pre-stressed pole.
DETAILED DESCRIPTION
The following presents a detailed description of various embodiments of the present subject matter with reference to the accompanying drawings. The embodiments of the present subject matter are described in detail with reference to the accompanying drawings. However, the present subject matter is not limited to these embodiments which are only provided to explain more clearly the present subject matter to a person skilled in the art of the present disclosure. In the accompanying drawings, reference numerals are used to indicate like components.
The specification may refer to “an”, “one”, “different” or “some” embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.
As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and/or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being “attached” or “connected” or

“coupled” or “mounted” to another element, it can be directly attached or connected or coupled to the other element or intervening elements may be present. As used herein, the term “and/or” includes any and all combinations and arrangements of one or more of the associated listed items.
As used herein, the term “M40” refers to a grade of concrete, more specifically, M40 grade stands for it's a mix of concrete with a characteristic compressive strength of 40 N/mm2.
Referring to FIGURES. 1A-1E, FIGURE 1A illustrates a mixing design for the pre-stressed pole 10, FIGURE 1B illustrates a trial cube testing for the pre-stressed pole 10, FIGURE 1C illustrates a form work for the pre-stressed pole 10, FIGURE 1D illustrates a pre-tensioning and casting for the pre-stressed pole 10, FIGURE 1E illustrates cutting tendons and de-shutting for the pre-stressed pole 10, where the pre-stressed pole 10 is ready for installation, as an example embodiments of the present disclosure. A pre-stressed pole 10 comprises an elongate structure formed of concrete mix. The concrete mix comprises a portion of cement, a portion of gravel, and a fine aggregate mixture. The fine aggregate mixture comprises a predefined ratio of sand and bottom ash, where the ratio is modifiable to generate a required strength of the concrete. In an embodiment, shown in FIGURE 1A, the concrete mix is designed to generate a targeted strength of M40 grade concrete, and a complete volume of the fine aggregate sand is replaced partly by bottom ash by a range of, for example but not limited to 50 % to 55 %. In an embodiment, as shown in FIGURE 1B, manufacturing of the pre-stressed pole 10 comprises a trial cube testing. Here, various compositions of the bottom ash and sand are tested, and the test showed that replacing the complete volume of sand by, for example but not limited to 50 % to 55 %, of bottom ash generates a required strength of M40 grade concrete. In another embodiment, the test showed that replacing the complete volume of sand by 50 % of bottom ash generates a required strength of M40 grade concrete for the construction of the pre-stressed pole 10.

In an embodiment, as shown in FIGURE 1C, manufacturing of the pre-stressed pole 10 comprises a form work that is constructed from mild steel (M S) sheet, which is fabricated as per drawings for casting of the pre-stressed pole 10. In an embodiment, as shown in FIGURE 1D, manufacturing of the pre-stressed pole 10 comprises pre-tensioning and casting of the poles, where pre-tensioning of 175 kg/sq.mm of wires is used to caste the pre-stressed pole 10. In an embodiment, as shown in FIGURE 1E, manufacturing of the pre-stressed pole 10 comprising cutting of tendons and de-shutting of the wires, wherein the pre-tensioned wires were cut after 28 days, and shuttering is removed, and wherein the pole is ready for installation after 28 days of curing.
FIGURE 2 illustrates a front view of the pre-stressed pole 10 after installation, as an example embodiment. In the pre-stressed pole 10 disclosed here, the complete volume of the fine aggregate sand is replaced partly by bottom ash by a range of, for example but not limited to 50 % to 55 %. For example, the top portion of the pre-stressed pole 10 comprises a 100 mm projection of 4 mm ø earth wire 12. The top portion also comprises hook 14 for tying the safety belt. A lifting hook 16 is positioned below the hook 14. A 4-mmØ earth wire 18 is drawn across length of the pre-stressed pole 10. Another lifting hook 20 is positioned below the hook 14, substantially proximal to the bottom section of the pre-stressed pole 10. A lower end portion 20 of the 4-mmØ earth wire 18 is constructed below the ground level.
The general manufacturing requirements for the pre-stressed pole 10 state that:
a) The poles shall be manufactured as per approved drawings and specifications complying the requirements of all applicable IS Codes such that its strength in the direction of the line shall not be less than one quarter of the strength required in transverse direction.
b) Mix design done earlier, not prior to one year may be considered adequate for work provided there is no change in source and the quality of the materials.

Furthermore, the mix-design shall specify 3-, 7- and 28-days’ cube strengths along with other details as per relevant IS.
c) Pre-stressing shall be done using a dynamometer (4mm diameter). Indented wires are only used and the concrete strength at transfer of pre-stress shall not be less than half the 28 days characteristic strength of cube.
d) All tendons are cut flushing the surface and shall not remain projected. End capping at both ends of each pole shall be done preferably with sealing compound / applying three coats of anti-corrosive bituminous paint confirming to IS: 9862/1981 after grinding the exposed reinforcement.
The pre-stressed pole 10 using bottom ash a fine aggregate contributes to these following areas:
• Mass production of electric poles using bottom ash can benefit cost saving in pole manufacturing cost also disposal cost of bottom ash can be saved.
• Manufacturing of electric poles, compound pole using bottom ash will help in addressing the issue of bottom ash handling/disposal across the organization & nation.
• Sustainable development by saving the natural scarce resource and non-exploration of sand will prevent erosion of riverbanks and flood.
Referring to FIGURES 3A-3D, FIGURE 3A illustrates a test report of the concrete mix design used in the pre-stressed pole. FIGURE 3B illustrates a test report based on a trial mix design of the concrete mix that is used in the pre-stressed pole. FIGURE 3C illustrates a test report based on mechanical testing performed for crushing strength of the concrete mix that is used in the pre-stressed pole. FIGURE 3D illustrates a test report based on mechanical testing performed for consistency, fineness, setting time, compressive strength, and specific gravity of the concrete mix used in the pre-stressed pole.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is, therefore, contemplated that such modifications can be made without departing from the scope of the present invention as defined.

We Claim:
1. A pre-stressed pole comprises:
an elongate structure formed of concrete mix; wherein the concrete mix comprising:
a portion of cement;
a portion of gravel; and
a fine aggregate mixture comprising a predefined ratio of sand and bottom ash, wherein the ratio is modifiable to generate a required strength of the concrete.
2. The pre-stressed pole as claimed in claim 1, wherein the concrete mix is designed to generate a targeted strength of M40 grade concrete, and wherein a complete volume of the fine aggregate sand is replaced partly by bottom ash by a range of 50 % to 55 %.
3. The pre-stressed pole as claimed in claim 1, wherein manufacturing of the pre-stressed pole comprising a trial cube testing, wherein various compositions of the bottom ash and sand are tested, wherein the test showed that replacing the complete volume of sand by 50 % to 55 % of bottom ash generates a required strength of M40 grade concrete.

3. The pre-stressed pole as claimed in claim 1, wherein manufacturing of the pre-stressed pole comprises a form work that is constructed from mild steel (M S) sheet, which is fabricated as per drawings for casting of the pre-stressed pole.
4. The pre-stressed pole as claimed in claim 1, wherein manufacturing of the pre-stressed pole comprising pre-tensioning and casting of the poles, where pre-tensioning of 175 kg/sq.mm of wires is used to caste the pre-stressed pole.

5. The pre-stressed pole as claimed in claim 4, wherein manufacturing of the pre-stressed pole comprising cutting of tendons and de-shutting of the wires, wherein the pre-tensioned wires were cut after 28 days, and shuttering is removed, and wherein the pole is ready for installation after 28 days of curing.