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PRE STRESSED CONCRETE ELECTRIC POLE (RECTANGULAR) (CAP:100 POLES/DAY OF 8 MTR TO 11 MTR LENGTH)

EIRI Team,

Prestressed concrete poles are commonly mass produced and are used in most countries for power transmission, antenna masts etc.

The main advantages of prestressed concrete poles are the following:

  1. Resistance to freeze-thaw effects in cold climate,
  2. Resistance to corrosion in moist conditions and to erosion in desert areas,
  3. Easy handling and transportation due to less self-weight,
  4. Fire resistance,
  5. Easy installation,
  6. Clean and neat appearance, and
  7. Increased crack resistance and improved rigidity.

These advantages have promoted the use of prestressed concrete poles all over the world. In India, prestressed concrete poles are generally manufactured by the long line method.

The maximum amount of resistance in a pole is generally required at the base and, so, the maximum cross sectional area is required at the base section. Poles are generally tapered with a hollow core to reduce the weight. For small lengths of upto 12 m length, square or rectangular cross sections are generally provided.

These shapes are easy to construct and transport. I-section shapes are also provided to the poles. However, these may be prone to more corrosion as a larger area of the surface may be exposed to environment. Tubular sections are preferred for large lengths of poles.

For measuring uprightness or straightness of a pole, it shall be placed lengthwise (with smaller cross section side parallel to rigid surface) on a rigid straight surface. Then using a measuring steel scale, graduated in mm, measure the distance (deviation) of pole surface from the rigid surface at several locations along the length of the pole. At least two measuring  in each one meter length of the pole should be taken . The largest value  of the measured distance (deviation) shall be taken for determining uprightness. Similar measurements should be taken on the pole laid with larger cross section side parallel to the rigid surface.

 

USES AND APPLICATION

  •           In communication – Telephone line, cable TV, Tower in location where space are restricted.
  •           Transmission and distribution line.
  •           In street lighting, garden, rest house complex, park and any other public area.
  •           As traction pole for Electrified Rapid Transit System (ERTS).

According to industry statistics, there were an estimated 10,000 establishments engaged in manufacturing concrete products, from a combination of cement and aggregate. Products in this industry were valued at $10.16 billion in 2012, down from $15.99 billion in 2010, with industry-wide employment of 20,00,000 workers. The industry has been negatively impacted by the global economic recession that economists claimed was beginning to show some signs of a slow recovery in 2014.

During 2010 the total number of establishments fell to 8000, and the workforce dropped to 15,12,153 workers from 96,068 in 2008. In contrast, product shipments reached $12.21 billion for 2010, an increase from the $10.16 billion that reported in 2010

P.C.C. Poles are essentially made of concrete which are inevitably less costly and more economically maintainable than the conventional steel poles. They are of two types depending upon the end use of the pole-Low tensile and High Tensile Line. The latter is primarily used for transmission of electricity. Prestress Cement Concrete Poles are essentially made of concrete.

High tensile wire is inserted into the pre-designed moulds and stretched to reach a certain tension.

 

Galvanised wire is fixed inside the mould for earthing following which a right proportion of concrete mix is poured. Then, the concrete is compacted through vibration to produce high strength concrete poles. After 72 hours, the tension is released and demoulding done. The poles are put under water sprinkler system for a period of 28 days. (Concrete cubes are tested to ascertain the ET

 

Market Potential:- In most cases concrete poles are substitutes for wood and iron poles. In our country transmission, distribution, communication lines and street lights use wood or iron poles. Cutting trees for harvesting wood poles further aggravates the deforestation problems of the country. Iron poles are imported from abroad thus consuming our scarce foreign exchange resources. The use of concrete poles, therefore, saves out forests and conserve our foreign exchange. Besides these poles serve for a much longer time than wood poles. Use of concrete poles for transmission and distribution lines has been expanding in many parts of the country during the last 10 years. This trend should continue for conserving our forests. Concrete poles are extremely heavy and as a result are very expensive to transport. Thus, if economies of scale allow, their production should be distributed in different areas to avoid excessive transport cost. As the Amhara Region is one of the largest regions in the country, it requires many and long transmission, distribution and communication lines and also many lighting poles, The existing and future demand for concrete poles will justify the establishment of one or two concrete and pile poles making plant in the Region.

Source of Raw material:- The main raw materials are cement, gravel, sand and wire. The first three will be secured from local sources and the last will be imported.

 

Process and Technology:- There are two technologies for producing concrete poles and piles-vibration process and the pre-cast spinning (centrifugal compaction) process. The spinning process is believed to be better than the vibration process. For this project idea, the spinning process is taken to estimate costs and production volume. The main stages in this process are mixing of cement and aggregate; wire straightening, cutting and assembling; mould setting; concrete feeding; spinning; steam curing; stripping; indicating water curing; air curing and inspection. More than 22 sets of machines are used for producing concrete poles and piles. The main ones are batch plant, concrete injection plant, spinning machine, wire straightening and cutting machine, wire-caging stand, wire heading machine, mould rolling device, overhead cranes, etc.

Detailed Contents:

INTRODUCTION

B.I.S. SPECIFICATION

SPECIFICATION OF PRESTRESSED CONCRETE POLE FOR OVERHEAD POWER TRACTION AND TELECOMMUNICATION LINE

RAW MATERIALS FOR PRE STRESSED CONCRETE POLE

USES AND APPLICATION

QUALITY STANDARDS

PRE COST CONCRETE COMPONENTS AND EQUIPMENTS

Use of ready-mix concrete (RMC)

Pole-testing equipment

MARKET SURVEY

OVERVIEW OF POWER SECTOR

RURAL ELECTRIFICATION STATUS IN INDIA

PRESENT MANUFACTURE OF PRESTRESSED ELECTRIC POLE

PRESTRESSED CONCRETE ELECTRIC POLES

PROCEDURE FOR PRESTRESSED POLE MANUFACTURE

MANUFACTURING DETAILS OF PRESTRESSED CONCRETE POLE

(PSC POLES) (RECTANGULAR)

PROCESS FLOW DIAGRAM

 

DESIGN SPECIFICATION OF PRESTRESSED CONCRETE POLE

TESTING METHOD FOR PRESTRESSED CONCRETE POLE

TECHNICAL DATA OF PSC POLES

CURING SYSTEM FOR PSC POLE

REQUIREMENT OF BATCHING PLANT

SUPPLIERS OF PLANT AND MACHINERY

CONCRETE BATCHING AND MIXING PLANT

SUPPLIERS OF PLANT AND MACHINERIES (IMPORTED)

SUPPLIERS OF RAW MATERIALS

 

APPENDIX – A :

  1. COST OF PLANT ECONOMICS
  2. LAND & BUILDING
  3. PLANT AND MACHINERY
  4. FIXED CAPITAL INVESTMENT
  5. RAW MATERIAL
  6. SALARY AND WAGES
  7. UTILITIES AND OVERHEADS
  8. TOTAL WORKING CAPITAL
  9. COST OF PRODUCTION
  10. PROFITABILITY ANALYSIS
  11. BREAK EVEN POINT
  12. RESOURCES OF FINANCE
  13. INTEREST CHART
  14. DEPRECIATION CHART
  15. CASH FLOW STATEMENT
  16. PROJECTED BALANCE SHEET

EIRI have recently prepared the Detailed Project Report on  PRE STRESSED CONCRETE ELECTRIC POLE (RECTANGULAR) (CAP:100 POLES/DAY OF 8 MTR TO 11 MTR LENGTH), where Land Area required is 2.5 Acres, Plant and Machinry Cost would be Rs. 21.14 Cr., Return 21% and BEP 65%.

Entrepreneurs may purchase a copy of the said report from www.eiriindia.org or may call on +91 9811437895 Sudhir Gupta