Hubli Electricity Supply Company Limited

1 HUBLI ELECTRICITY SUPPLY COMPANY LIMITED TECHNICAL SPECIFICATIONS TECHNICAL SPECIFICATION FOR 8 METRES / 9 METRES RCC POLES 1.0 SCOPE: 1.1 The specification covers manufacture, curing testing and supply of 8.0 and 9.0 meters long RCC poles generally as per drawings enclosed with this specification, and are intended to be used on 11kv and LT over head electric distribution lines. 1.2 Irrespective of anything said or omitted herein the materials shall be suitable for the purpose intended for and shall confirm to the latest edition of the Indian standard specification IS: 785. 2.0 MATERIALS 2.1 Cement: The cement used in the manufacture of RCC poles shall be any of the following: 1. 53 grade ordinary Portland Cement conforming to IS 12269 / 1987 2. Portland slag cement conforming to IS: 455 / 1989 3. Portland pozzolana cement: Fly ash based conforming to IS: 1489 Part 1 / 1991 4. Portland pozzolana cement: Calcined clay based conforming to IS: 1489 Part 2 / 1991 5. Rapid hardening Portland Cement conforming to IS: 8041 / 1990 2.2 Aggregates: Aggregates used for the manufacture of RCC poles shall confirm to IS- 383. It shall be graded hard broken granite stones of size 10mm to 20mm. Under no case the size of the jelly shall exceed 20mm. The whole of the aggregate shall pass through a sieve having aperture not exceeding three quarters of the minimum distance between the main reinforcing bars. The sand shall be of the quality fit for use in RCC works i.e. river sand and sieved and free from alkaline / acidic materials. 2.3 Reinforcement : Reinforcing bars and wires used for the manufacture of RCC poles shall be as below:- a) Mild steel medium, tensile steel bars and hard drawn steel wire confirming to IS: 432 / 1982 (Part I & II) b) The steel of tor-50 grade, confirming to latest edition of IS-1786 / 1985. c) Quality of MS rounds used for stirrups shall comply with the requirement of IS: 2062 / 1999. The reinforcing bars used shall be of requisite length as per drawing and no joint shall be allowed. All joints and stirrups shall be welded properly. If not welded the lap length shall not be less than 40 times the diameter of bars. The cover of concrete over the main reinforcement shall be 30mm under the normal working conditions and shall not be under any circumstances less than 20mm. The surface of all reinforcement shall be free from loose scale, loose rust, oil, grease, clay or other material that may have deteriorating effect on the bond between reinforcement and concrete. 2.4 Admixture: - The admixtures, if used shall conform to IS: 9103. 2.5 Concrete: - The minimum grade of concrete to be used for the manufacture of RCC Poles shall be M 25 and shall comply with requirements of IS-456. 2.6 Water: -The requirement of water to be used for mixing and curing shall conform to the requirements given in IS: 456. Seawater shall not be used. 2 3.0 STANDARDS:- The standards adopted for various materials, design, manufacture shall be the latest version of the following: 1. The RCC poles shall conform to IS: 785 / 1998. 2. The quality of concrete shall conform to IS: 456/2000. 3. The testing of prototype poles shall conform to IS: 2905/1989. 4.0 DESIGN: - 4.1 The RCC poles shall be manufactured as per the enclosed drawings and as per the following details. Sl. No. Particulars Type of RCC poles 8 Mtr. Rectangular section 9 Mtr. Rectangular section 9 Mtr. square section 1 Working load (Kgs) (Transverse) 115 145 150 2 Working load (Kgs) (Longitudinal) - - 150 3 Factor of safety 2.5 2.5 2.0 4 Depth of planting (Mtr.) 1.5 1.7 1.7 5 Size of Tor 50 Reinforcement steel (mm) 10 10 12 6 Size of MS round for stirrups (mm) 6 6 6 7 No. of Stirrups 56 60 60 5.0 MANUFACTURE: 5.1 The poles shall be manufactured as per the drawings enclosed. All reinforcements shall be accurately placed and maintained in position during ma