You cannot build a wind turbine without using concrete. Indeed, for each turbine, requires 900 tons of steel, 2500 tons of concrete and 45 tons of plastic.
The above image is in a design manual.
Concrete seems to have been developed using a mixture of mud and straw to form bricks and used gypsum and lime to make mortars when the Egyptians built their pyramids 5000 years ago. The Romans developed it into a form quite similar to the concrete of today. In 1824 Portland Cement was invented by an Englishman, Joseph Aspdin of Leeds, Yorkshire.
Alvord Lake Bridge was built in 1889 in San Francisco, CA. This bridge was the first reinforced concrete bridge, and it still exists today, over one hundred years after it was built!
In 1891, the first concrete street in American was built in Bellefontaine, Ohio. Today, pervious concrete is being advocated as the best, and most environmentally friendly, surface for streets.
Gradually the use of concrete was used extensively for homes and infrastructure.
The Making of Cement today
Cement is manufactured through a closely controlled chemical combination of calcium, silicon, aluminum, iron and other ingredients.
Common materials used to manufacture cement include limestone, shells, and chalk or marl combined with shale, clay, slate, blast furnace slag, silica sand, and iron ore. These ingredients, when heated at high temperatures form a rock-like substance that is ground into the fine powder that we commonly think of as cement.……….
The most common way to manufacture portland cement is through a dry method. The first step is to quarry the principal raw materials, mainly limestone, clay, and other materials. After quarrying the rock is crushed. This involves several stages. The first crushing reduces the rock to a maximum size of about 6 inches. The rock then goes to secondary crushers or hammer mills for reduction to about 3 inches or smaller.
The crushed rock is combined with other ingredients such as iron ore or fly ash and ground, mixed, and fed to a cement kiln.
The cement kiln heats all the ingredients to about 2,700 degrees Fahrenheit in huge cylindrical steel rotary kilns lined with special firebrick. Kilns are frequently as much as 12 feet in diameter—large enough to accommodate an automobile and longer in many instances than the height of a 40-story building. The large kilns are mounted with the axis inclined slightly from the horizontal.
The finely ground raw material or the slurry is fed into the higher end. At the lower end is a roaring blast of flame, produced by precisely controlled burning of powdered coal, oil, alternative fuels, or gas under forced draft.
As the material moves through the kiln, certain elements are driven off in the form of gases. The remaining elements unite to form a new substance called clinker. Clinker comes out of the kiln as grey balls, about the size of marbles.
Clinker is discharged red-hot from the lower end of the kiln and generally is brought down to handling temperature in various types of coolers. The heated air from the coolers is returned to the kilns, a process that saves fuel and increases burning efficiency.
After the clinker is cooled, cement plants grind it and mix it with small amounts of gypsum and limestone. Cement is so fine that 1 pound of cement contains 150 billion grains. The cement is now ready for transport to ready-mix concrete companies to be used in a variety of construction projects.
Although the dry process is the most modern and popular way to manufacture cement, some kilns in the United States use a wet process. The two processes are essentially alike except in the wet process, the raw materials are ground with water before being fed into the kiln.
China has the largest cement industry in the world. Thus it has contributed to massive environmental pollution. India is the next biggest producer. The United States is the third on the list of main producers, 34 American states have cement manufacturing plants, also they have two plants in Puerto Rico. The brands are CEMEX, Lehigh Hanson Inc., Texas Industries Inc., and LafargeHolcim.. Fourth on the list is Iran, the largest provider in the Middle East. There are other countries manufacturing cement, but by far, China is has the greatest output.
This site explains how cement is made. Here is a graphic from that site:
Since we humans began farming, we developed recipes for making meals from food we cultivated. It was an obvious step to then experiment with materials and explore the skill of metallurgy by mixing resources from the environment. All science experiments manipulate natural resources to obtain, sometimes by accident, some production which brings amazement, pride and power to those who invented and marketed it to their fellow humans.
This is the basic recipe for cement:
The most common raw rock types used in cement production are:
- Limestone (supplies the bulk of the lime)
- Clay, marl or shale (supplies the bulk of the silica, alumina and ferric oxide)
- Other supplementary materials such as sand, fly ash/pulverised fuel ash (PFA), or ironstone to achieve the desired bulk composition
There is a massive amount of plant required in the cement production industry. The machines alone, and their maintenance, are a major investment.
The hammer mills and crushing process is extensive and primary to the task of making cement.
Those working in the construction industry around the world will know the hazards of silica dust and the danger it poses to their health. Some will be protected by their employer, many will not. This site offers solutions and understanding of the issues.
In America they have regulated for adequate protection of construction industry workers. The new OSHA PEL was approved in 2016, with employers in the construction industry required to comply by June 23, 2017.
Not only do workers suffer, but many quarries are close to residential areas, such as the one in Leith, Scotland. The dust is airborne in the process of quarrying and transporting.
The well known disease, silicosis, is caused by breathing in the airborne silica dust, and is killing millions of workers and nearby members of communities, around the world. It is a slow and horrible way to die.
The UK has been, and still is, a major supplier of aggregates for the construction industry.
Where possible, tight regulations are brought in to protect workers and others in the vicinity of a quarry, as described in this document.
In creating windfarms, we are taking beautiful, wild areas of land (Scotland is known for its wild magnificent landscapes). As we speak, one of the biggest windfarms in Scotland is proposed close to where I live. Thus, it prompted me to investigate the environmental costs of wrecking this mostly wild landscape with tons of cement, steel and plastics. These monstrous turbines will never biodegrade. They contribute tiny amounts of electricity to the Grid, yet are so hyped by marketing that people are being told they can now buy 100% renewable electricity right into their home.
The industries who supply the basic materials, whilst making great profits from the hype of the windfarm industry, are damaging the health of all those they employ, right down through the supply chain. There is nothing Green about windpower, but we constantly suffer Greenwashing hype.
But employment is held as the carrot dangled before workers in the construction industry, and many see no other option but to take on these dangerous occupations. There is little regard for the health of miners or construction workers who seem forgotten when these clean looking monsters rise up. Pictures of windfarms are taken in the bright sun to present gleaming images. The truth is hidden by lies and deceit, as always.
And after all that use of resources, damage to the environment and billions of pounds spent, still, these concrete foundations can fail and bring 33 turbines crashing down.