PRESTRESSED CONCRETE POLES (PSC POLES)
[EIRI/EDPR/1534] J.C.328 (US$) 518 (INR)
INTRODUCTION
Wooden, steel and concrete poles were used for power distribution lines since 19th century.
The first poles used were wooden poles. When demand for poles increase and as the power lines under construction required longer poles suitable for resisting larger horizontal forces, steel poles were introduced in substitution to wood.
Though both materials are still in use throughout the world, with wood primarily used for short length small forces country lines the general trend is to substitute both the materials with concrete and Use reinforced and prestressed concrete poles instead.
Wooden have limited life and steel poles have a longer life compared to wooden poles requires continuous maintenance for protection against corrosion concrete and particularly prestressed concrete poles can be considered as having an unlimited life without maintenance cost for their corrosion protection. Poles supporting power lines are subjected to relatively small vertical forces and primarily to large horizontal forces at bottom. The horizontal forces at their top are smaller along the axis of the power line and much larger on direction perpendicular to it. As in the perpendicular direction the pole must resist the horizontal forces caused from wind loads against the poles and the wires carried by them.
In view of the difference in the horizontal forces to which a pole is subjected, the original solution given and, still adopted by authorities is to give the pole a cross section with larger moment in one direction and smaller one in the direction perpendicular to it like example a rectangular or double T cross section. Experience however has shown that concrete poles with a circular cross section are preferable to poles with rectangular or T section as they resist better impact loads and little extra cost give the added advantage that they have an equal resistance to horizontal forces in all direction. The circular cross section besides the advantage mentioned earlier lends itself to very well to use for the manufacture of poles of the spinning process. As well known the spinning process is one of the best methods of casting freshly cast concrete, as the centrifugal forces applied to concrete, secure a dense, excellent quality concrete at relatively less manufacturing costs. The pre stressed hollow or tubular pole have proved to be more economical, easily transported and erected due to lightweight.
COST ESTIMATION (US$ DOLLOR)
Plant Capacity 117.00 Nos/Day
Land & Building (16000 Sq.Mtr) US$ 10.60 Lacs
Plant & Machinery US$ 10.89 Lacs
W.C. for 2 Months US$ 5.56 Lacs
Total Capital Investment US$ 27.55 Lacs
Rate of Return 35%
Break Even Point 59%
CONTENTS
INTRODUCTION
USES OF SPUN CONCRETE POLE OTHER THAN TRANSMISSION AND DISTRIBUTION LINE
QUALITY STANDARDS
SPECIAL REPORT – EQUIPMENT
USE OF READY-MIX CONCRETE (RMC)
POLE-TESTING EQUIPMENT
MARKET SURVEY
PRESTRESSED CONCRETE ELECTRIC POLES
THE MANUFACTURE OF TUBULAR PSC POLES CONSISTS OF THE FOLLOWING OPERATION:
CURING SYSTEM FOR PSC POLE
REQUIREMENT OF BATCHING PLANT
PRINCIPLE AND MANUFACTURING TECHNOLOGY OF CONCRETE SPUN POLE OULDS
DESIGN OF PSC POLES
SUPPLIERS OF PLANT AND MACHINERY
ROUND PRESTRESSED ELECTRIC CONCRETE POLE STEEL
MOULD 9M 10M 11M
SUPPLIERS OF MACHINERY
SUPPLIERS OF RAW MATERIALS
APPENDIX – A:
01. PLANT ECONOMICS
02. LAND & BUILDING
03. PLANT AND MACHINERY
04. OTHER FIXED ASSESTS
05. FIXED CAPITAL
06. RAW MATERIAL
07. SALARY AND WAGES
08. UTILITIES AND OVERHEADS
09. TOTAL WORKING CAPITAL
10. TOTAL CAPITAL INVESTMENT
11. COST OF PRODUCTION
12. TURN OVER/ANNUM
13. BREAK EVEN POINT
14. RESOURCES FOR FINANCE
15. INSTALMENT PAYABLE IN 5 YEARS
16. DEPRECIATION CHART FOR 5 YEARS
17. PROFIT ANALYSIS FOR 5 YEARS
18. PROJECTED BALANCE SHEET FOR (5 YEARS)
