1

Wind turbine concrete towers

History

Steel vs concrete

Nees Project

Design challenges

Concrete specification

Construction challenges

Future

2

History

Tvind 1970

Foundation slabs 1970 - 2011

Nysted Havmøllepark 2003

Thornton Wind Farm 2006

Nees Project 2010

3

Tvind

Precast shells

4

5

Nysted Havmøllepark Foundations

6

Thornton Wind Farm

7

Steel vs concrete

AND: MONEY TALKS!

8

Nees Project

Client: Siemens Wind Power

Consultant: COWI

Contractor: Aarsleff

9

10

Foundation

11

Reinforcement

12

Slipforming

13

14

Loads samt:

•Is

•Strøm

•Egenvægt

•Dynamik

•Stivhed

15

16

17

18

19

20

21

Øresund Bridge

22

23

24

Concrete specification

25

26

27

28

29

Construction challenges

Construction speed

Construction cost

Structural reliability

Structural predictability

Just-in-time schedule

Climate

30

Future

Nysted Havmøllepark

Thornton Bank

Nees

150m onshore towers

all-in-one offshore structures

thin-walled structures

fibre-reinforced concrete

5500 mm

9100 mm

6500 mm

3000 mm

+0.14 MLLWS+0.56 LWS

+2.29 MSL

+6.05 (50 year)

4.5m

D6: -27.0

Stable erosion protection.

R 300

0?

+8.00

0.00