Durable Reinforced Concrete Power Transmission Poles Made of Nanomodifi ed Concrete — the Future of Digital Distribution Networks

Page 1
background image

The MAIN JOURNAL for POWER GRID SPECIALISTS in RUSSIA

3 - 6   J U N E   2 0 1 9

MADRID, SPAIN

The MAIN JOURNAL for POWER GRID SPECIALISTS in RUSSIA

3 - 6   J U N E   2 0 1 9

MADRID, SPAIN


Page 2
background image

30

Durable Reinforced Concrete
Power Transmission Poles Made
of Nanomodifi ed Concrete — the Future
of Digital Distribution Networks

Valentina SOLOVIOVA,

D.Sc., Prof. of Emperor Alexander I 

St.-Petersburg State Transport University

Peter ROMANOV,

Ph.D, Ch.Eng. Scientifi c Research 

Laboratory of Electrical Grid Construction

Liubov KACHANOVSKAYA,

PhD, Нead of Scientifi c Research 

Laboratory of Electrical Grid Construction

Sergey KASATKIN,

Eng. Scientifi c Research Laboratory 

of Electrical Grid Construction

Tatyana SBOYCHAKOVA,

Eng. Scientifi c Research Laboratory

of Electrical Grid Construction

Improving the reliability and durability of reinforced concrete poles for overhead transmis-
sion lines is a direct way to reduce costs when constructing and operating energy facilities. 
Modern chemical additives can signi

 cantly affect the structure of concrete and improve its 

operational properties: strength, density, freeze-thaw, water and corrosion resistance. Iden-
ti

 cation and digital certi

 cation of power transmission poles with new properties is a guar-

antee of their sustained quality. The paper presents data on the industrial production of poles 
from nanomodi

 ed concrete. Also, the paper considers directions for further work on creating 

the uni

 ed series of 0.4 and 6-10 kV reinforced concrete power transmission poles character-

ized by high durability for digital distribution electrical networks.

A

s of today, the length of overhead transmission lines with 

up to 20 kV voltage exceeds 2 million km in Russia. Tra-

ditionally these overhead lines are performed on vibrated 

concrete poles.

The development of economy, new technologies and popula-

tion  needs  requires  upgrading  distribution  networks  in  regards 

to increasing their length and functionality (Figure 1). New types 

of conductors are used for increasing transmission capacity. Ap-

plication of additional fi ber-optic links is required for establishing 

communication channels. Growing needs lead to load increase 

of  power  transmission  poles  and  enhanced  requirements  for 

their load-carrying ability. Telecommunications networks require 

increased  reliability  coeffi  cient  for  power  transmission  poles 

(1.5 times more for ice loading). In addition, the poles of distribu-

tion networks are often constructed along highways. As a result, 

they are exposed to the aggressive infl uence of deicing products 

in winter.

Thus, there is a need to increase such operational character-

istics of vibrated reinforced concrete poles as load-carrying ability 

and crack, freeze-thaw, water and corrosion resistance.

The solution of this task is achieved through the rational use of 

the internal reserves of the cement-containing system — applica-

tion of new activating chemical additives.

A complex additive for concrete consisting of several compo-

nents of diff erent nature and specifi cally SiO

2

·nH

2

O nanodisper-

sions was developed at the Department of Engineering Chemistry 

and Natural Science of St. Petersburg State Transport University 

(PGUPS).  Presented  nanodispersions  promote  the  formation  of 

hardly soluble compounds that are more resistant to the aggres-

sive  eff ects  of  salts  and  have  a  positive  eff ect  on  the  corrosion 

resistance of concrete.

Besides, the formation of an additional amount of hydrate joints 

with a needle-shaped structure is capable to provide micro rein-

forcing of concrete, its compaction, and as a result, increasing its 

strength, crack resistance and durability.

It  is  obtained  that  eff ective  chemical  activation  of  nanomodi-

fi ed concrete signifi cantly heats the curing mass. It has a positive 

eff ect on hydration processes and allows engineers to reduce sig-

nifi cantly the temperature in the curing chambers and to abandon 

their heating at all in summer.

Fig. 1. 10 kV power transmission poles for 
overhead-underground transition

OVERHEAD

TRA

N

SM

I

SS

I

O

N

 L

IN

ES


Page 3
background image

3

1

The  developed  complex  additive  was  tested  at  the 

factories of "PO "Energozhelezobetonivest", LLC during 

the  manufacture  of  SV95-3s  reinforced  concrete  poles 

with B30 W6 F

1

200 design parameters of concrete. Stan-

dard plant products from concrete mixture containing only 

polycarboxylate-based  additives  were  taken  as  control 

samples. The developed complex additive is comparable 

in cost to the additive used in the plant. The additives dos-

age was kept at the same level. The poles were tested 

according to state standard 8829-94 (GOST 8829-94) for 

assessing their strength, hardness and crack resistance. 

Such physico-mechanical parameters of concrete as the 

compressive strength (after curing, at the age of 7 and 

28 days), water and frost resistance were under control.

The test results of reinforced concrete poles showed 

that products with the developed chemical additive had 

lower values of such indicators as the number and aver-

age width of cracks and poles defl ection.

Samples  of  nanomodifi ed  concrete  with  developed 

additive diff ered in high strength. The kinetics of concrete 

strength  development  when  curing  at  a  temperature  of 

60 °C (reduced temperature relative to usual values) is 

presented in Figure 2.

The  strength  of  nanomodifi ed  concrete  in  compres-

sion at the age of 28 days exceeded the control values by 

34%. It corresponds to class B40 (Figure 2).

Samples  of  nanomodifi ed  concrete  diff ered  in  in-

creased  water  resistance  (twice  more),  corresponding 

to W12 mark. Frost-resistance increased by 2.5 times. It 

conforms to F

1

500 mark.

Nano-modifi ed concrete with B30 design class can be 

obtained by reducing cement consumption by 30%, while 

water resistance increasing by 3 steps to W10 mark, and 

frost-resistance double enhancing to F

1

400 mark.

The results indicate the eff ectiveness of developed ad-

ditive for manufacturing concrete products such as poles, 

piles, pad and chimney foundations.

As of today, the use of nanomodifi ed concrete at the 

plants of "PO "Energozhelezobetonivest", LLC allows en-

gineers to manufacture typical structures of increased du-

rability while maintaining the existing cost.

Signifi cant  savings  at  the  construction  stage  of  the 

facilities can be achieved by developing new designs of 

poles, piles and precast foundation with the use of mod-

ern  high-strength  and  durable  concrete  and  high  duty 

reinforcement. The list of topics recommended for imple-

mentation within the framework of PJSC "Rosseti" R&D 

already includes "Development of unifi ed series of extra 

durable  reinforced  concrete  poles  for  0.4  and  6-10  kV 

overhead  transmission  lines  using  nanomodifi ed  con-

crete  and  electronic  passport  elements".  The  develop-

ment of reinforced concrete poles with enhanced values 

of  load-carrying  ability  will  provide  an  increase  of  span 

length  for  overhead  lines  by  20-25%  and  an  economic 

eff ect by reducing the number of intermediate poles and 

related  costs  of  their  construction  and  maintenance. 

Nanomodifi ed concrete application will ensure a lifetime 

of reinforced concrete poles over 50 years (in some cases 

a lifetime can reach even 100 years). This will signifi cantly 

reduce repairing costs.

New power transmission poles will be equipped with 

radio-frequency  tags  (microchips)  containing  a  unique 

identifi cation number. This number provides access to the 

electronic passport and, hence, to information on poles 

life  cycle  and  technical  documentation  with  detailed  in-

formation on the released product and its characteristics. 

Electronic  certifi cation  of  reinforced  concrete  poles  will 

allow engineers to produce products diff erentially and to 

supply them on energy facilities taking into account indi-

vidual corrosion protection requirements. Products iden-

tifi cation  will  allow  the  customer  interested  in  quality  to 

choose poles based on their properties. In addition, it will 

increase the responsibility of the manufacturer and sup-

plier, ensure stable quality of the products used at the fa-

cilities, and exclude the supply of products mismatching 

the claimed characteristics. As a result, there will be no 

problems during operation. Information on each product 

with reference to specifi c power transmission pole will be 

added to the electronic passport of overhead line.

CONCLUSIONS

1.  A  complex  chemical  additive  for  concrete  has  been 

developed. It includes nanosize dispersions, which make 

it possible to produce nanomodifi ed concrete character-

ized  by  high  strength,  density,  freeze-thaw,  water  and 

corrosion resistance. Such concrete provides increased 

reliability and durability of structural units.

2.  The cost of reinforced concrete products made from 

extra  durable  concrete  does  not  diff er  from  the  cost  of 

standard structures. At the same time, the use of durable 

structures eliminates the need for repairs throughout the 

entire service life. This fact has the greatest importance 

for foundation structures — piles and pad and chimney 

foundations operating in rough soil conditions (there is no 

access to these structures during their operation).

3.  Early order of existing standard designs using nano-

modifi ed  concrete  can  signifi cantly  reduce  operating 

costs in the future.

4.  The development of new unifi ed series of reinforced 

concrete poles with increased reliability and durability for 

0.4 and 6-10 kV overhead lines will decrease the cost of 

transmission lines construction by means of reducing the 

number of poles per kilometer. Also, operation costs will 

be reduced due to the absence of repairs. A digital elec-

tronic passport will allow engineers to transfer all informa-

tion about the product to the IT system of electrical net-

work for solving the problems of production and technical 

management, monitoring and equipment diagnostics.  

Р

Fig. 2. Kinetics of concrete strength development

Scientifi c Research Laboratory

of Electrical Grid Construction

Tel.: +7 (911) 285-94-61, +7 (812) 309-39-61

E-mail: t.i.sboychakova@nilkes.ru      www.nilkes.ru

The 25th CIRED Session 
Special issue, June 2019


Читать онлайн

Improving the reliability and durability of reinforced concrete poles for overhead transmission lines is a direct way to reduce costs when constructing and operating energy facilities. Modern chemical additives can signifi cantly affect the structure of concrete and improve its operational properties: strength, density, freeze-thaw, water and corrosion resistance. Identification and digital certifi cation of power transmission poles with new properties is a guarantee of their sustained quality. The paper presents data on the industrial production of poles from nanomodifi ed concrete. Also, the paper considers directions for further work on creating the unifi ed series of 0.4 and 6-10 kV reinforced concrete power transmission poles characterized by high durability for digital distribution electrical networks.

Поделиться:

«ЭЛЕКТРОЭНЕРГИЯ. Передача и распределение»