Recent

Theme images by Storman. Powered by Blogger.

Recent in Sports

Home Ads

Comments

Ads

Random Posts

Saturday, 12 October 2019

Reinforced Cement Concrete (RCC) Poles

Reinforced Cement Concrete (RCC) Poles:



Reinforced Cement Concrete (RCC) poles and prestressed cement concrete (PCC) poles, rectangular or square in cross section, are very popular in rural electrification due to very low maintenance cost, corrosion resistant and free from oxidation. Such poles are provided with holes to reduce their weight and to make climbing on the poles easy. They can be cast at the erection side to minimise the transportation charges. Such poles are good to look at, require negligible maintenance, have insulating properties, last long and possess resistance to chemical action. The drawbacks of such poles are difficulty in their erection due to heavy weight, high initial cost and difficulty in transportation. Moreover R.C.C. poles once they are damaged are not repairable. Skilled labour is required for the fabrication and erection of the poles. R.C.C poles are generally used upto 11 kV single circuit and double circuit distribution lines. The span of such poles is 80 metres to 200 metres.


The raw materials which are required for the above types of poles are mortar and concrete. There are two types of mortar: cement mortar and lime mortar. The strength of the mortar depends on the ratio of cements and water. Mortar is a binding material and cement mortar is stronger than lime mortar. Concrete is a mixture of sand, cement and aggregate in water in different proportions. If steel rods, bars or mesh structures of steel are embedded into it to make it stronger, it is called steel reinforced concrete.

Important Properties of other commonly used Insulating Materials

SI. No.
Insulating Material
Volume resistivity ohms. cm
Breakdown Voltage kV/mm
Dielectric Constant
Max. Operating Temperature
Tensile Strength
1
Asbestos
16 x 10
3 to 4.5
2.5 - 3
500
22 - 28
2
Bakelite
(20-40) x 102
15 - 25
5.7
200
350 - 720
3
Cotton
1011 to 1016
4
--
90
--
4
Empire Cloth
1011 to 1016
15
2
--
--
5
Glass
greater than 107
10 - 40
3.5 - 3.9
500
420
6
Leatheroid Plain
--
14 - 17
--
90
--
7
Leatheroid Varnished
--
16-20
--
95
--
8
Mica
(10 - 200) x107
60 - 200
5 - 8
500
--
9
Micanite
--
12 - 24
--
--
--
10
Paper Varnished
--
20 - 40
4.5
80 - 115
--
11
Paper Varnished
(300 - 500) x 1012
16 - 12
2.5 - 4
95
--
12
Paper Plain
(5 - 100) x 1012
6-12
2 - 2.5
90
--
13
Polythene
3 x 1019
40
2.3
85
120 - 210
14
Porcelain
greater than 1013
35
6 - 7.5
1000
70 - 420
15
Polysterene
1019 - 1020
20
2.5
65
--
16
P.V.C
1012 - 1015
40 - 170
4 - 12
60 - 80
70 - 630
17
Press Board Plain
1012
8 - 14
5
90
--
18
Press Board Varnished
--
10 - 16
7.65
90
--
19
Press Board Oiled
--
28 - 36
3
90
--
20
Quartz (Silica)
(1 -2) x 1016
--
3.5 – 4.5
1100 - 1200
490
21
Resin
5.1 x 1016
11
--
--
--
22
Rubber Plain
(10 -15) x 1017
16 - 28
3.5
--
9 – 2.6
23
Vulcanised
(1 -10) x 1017
12 - 24
2.3 – 3.0
--
210 - 280
24
Silicon Compound
1015-1016
--
2.5 – 4.0
150 - 200
--
25
Wood Impregnated
--
26
4 - 8
--
--



0 on: "Reinforced Cement Concrete (RCC) Poles"