Wind Watch | The facts about wind power, wind energy, wind turbines, wind farms
What kind of platform is a wind turbine set in?
The steel tower is anchored in a platform of more than a thousand tons of concrete and steel rebar, 30 to 50 feet across and anywhere from 6 to 30 feet deep. Shafts are sometimes driven down farther to help anchor it. Mountain tops must be blasted to create a level area of at least 3 acres. The platform is critical to stabilizing the immense weight of the turbine assembly.
How much do wind turbines weigh?
In the GE 1.5-megawatt model, the nacelle alone weighs more than 56 tons, the blade assembly weighs more than 36 tons, and the tower itself weighs about 71 tons — a total weight of 164 tons. The corresponding weights for the Vestas V90 are 75, 40, and 152, total 267 tons; and for the Gamesa G87 72, 42, and 220, total 334 tons.
How much area is required for a wind power facility?
The huge turbines require a correspondingly large area around them clear of trees and other turbines to maximize the effect of the wind and avoid interference. They should have 10 rotor diameters of clearance in the direction of the wind and 3 rotor diameters in every other direction. In a line of several turbines perpendicular to the wind (as on a mountain ridge), the GE 1.5-MW model would need at least 32 acres and the Vestas V90 78 acres for each tower. In an array that can take advantage of the wind from any direction, the GE needs 82 acres and the Vestas V90 111 acres per tower.
In practice, the area varies, averaging about 50 acres per megawatt of capacity. On mountain ridges, the turbines are generally squeezed in at about 10 MW per mile.
Can the area around a wind turbine continue to be used?
Only by putting oneself in danger. Besides the unpleasant noises and distracting motion, wind turbines are not safe. They are high-voltage electrical devices with large moving parts. It is estimated that for every 100 turbines, one blade will break off (see
Larwood, 2005). In the winter, heavy sheets of ice can build up and then fall or be thrown off. Access to the land around wind turbines is usually restricted, even to the landowner.
Curing Concrete - How Long it Takes & How To Cure - The Concrete Network
HOW LONG DOES IT TAKE FOR CONCRETE TO CURE?
The entire curing period of concrete takes about a month, but your concrete will be ready for use sooner. Each project will vary slightly due to differences in the weather, concrete mix and placement and finishing techniques.
When waiting for concrete to dry, keep these timeframes in mind:
- 24 to 48 hours - after inital set, forms can be removed and people can walk on the surface
- 7 days - after partial curing, traffic from vehicles and equipment is okay
- 28 days - at this point, the concrete should be fully cured
Solved! This is How Long It Takes Concrete to “Dry”
After 7 days from pouring the concrete, you can drive on a new driveway.
By the time a week has passed the concrete will have reached approximately 90 percent of its final strength, and it’s usually safe to drive on it. If you have a large size vehicle, however, such as a 1-ton pickup truck, it’s a good idea to wait a few days or even a week longer.
At 28 days, concrete reaches its full strength and hydration is complete.
Although the bulk of the hydration process takes place in the hours and days immediately after the pour, concrete needs 28 days to fully dry.
Because Bob Villa is the Jeff Rense of the construction world.