Concrete is the most widely used construction material in the world. That’s a fact you probably already knew. What you might not know are some of the other cool facts about concrete. Here are three we think you’ll find interesting:
1) Concrete is stronger at high temperatures.
2) Wet concrete is more durable than dry concrete.
3) Concrete forms are better when they’re flexible.
These facts may seem surprising, but the science behind them is pretty straightforward. Let’s take a closer look at each one of these “cool” things you didn’t know about concrete.
Concrete is the most common manmade material on Earth. It is usually grey but can be made in any color. It is used to make buildings, bridges, sidewalks and roads.
Most people think of concrete as a boring building material. It’s the brown stuff that holds up our sidewalks, right? But it turns out there are lots of cool things about concrete that most people don’t know about. And these cool things are pretty important for our daily lives!
Concrete is made by mixing sand and gravel with cement and water. The mixture has to set or “cure” so it hardens into a solid mass. Cement is made from limestone and clay and other minerals. To make cement you have to crush the ingredients into a powder and heat them in a kiln at 2,700 degrees Fahrenheit (1,480 Celsius). The process uses huge amounts of energy, which creates pollution. In fact making cement creates about 5 percent of all carbon dioxide emissions worldwide!
The Romans invented concrete more than 2,000 years ago. They called it hydraulic cement because it hardened when mixed with water. Modern concrete has some extra ingredients that make it stronger, but Roman concrete was also very strong and long-lasting. Ancient Roman structures like the Pantheon in
Concrete is made from a combination of cement, aggregate (like rocks and sand), water and admixtures if needed.
Hydraulic cement bonds with water to form a hard stone-like mass. The chemical reaction between the materials in the cement and water is called hydration.
The chemical reaction that takes place during the hydration process causes the concrete to shrink as it cures. This can cause problems such as cracking if the concrete is not properly cured and protected.
There are many more cool things to learn about concrete, so stay tuned for more posts!
The Egyptians used lime and gypsum cements as far back as 3,000 B.C. to make plaster and mortar. The Romans were the first to use cement extensively in their vast building program, which included construction of roads, aqueducts, bridges, bathhouses and other structures. They used a type of cement called pozzolana made from volcanic ash found near Pozzuoli, Italy. Other early types of cements included those invented by the English chemist John Smeaton in 1756 and Scottish engineer John Loudon McAdam in 1820.
Modern concrete was invented by Joseph Aspdin in England in 1824 who cooked cement in his kitchen. It was named Portland Cement because the concrete made from it looked like Portland stone, a widely-used building stone in England. A Frenchman named Louis Vicat developed another type of concrete using lime instead of cement for binder after Aspdin’s patent expired.
Concrete is a mixture of paste and aggregates (rocks). The paste or matrix is made up of portland cement and water; the larger rocks are called coarse aggregate while the smaller particles are fine aggregate such as sand. Seawater can also be used as an ingredient to make concrete when there is a
Concrete is a building material made from a mixture of cement, aggregate (typically gravel and sand), water and sometimes additives like fly ash or slag cement. Concrete hardens when these ingredients are mixed with water, thanks to a chemical process known as hydration.
Hydration begins with the mixing of cement and water. The main ingredient in cement is calcium oxide, also known as lime. When lime comes into contact with water, it undergoes a chemical reaction that produces microscopic crystals called hydration products. These crystals grow and link up with other crystals to form an interlocking network of solid calcium silicate hydrates (CSH) that fills all the spaces between the gravel and sand particles in the concrete mix. This is what makes concrete so strong and durable.
The more CSH that forms, the stronger the concrete becomes. But there’s a limit to how much CSH can form because there’s only so much lime available in hydrated cement. That’s why adding more water doesn’t necessarily make concrete stronger; additional water only makes it weaker because it reduces the amount of CSH produced for a given amount of cement.
Portland cement, the most widely used hydraulic cement in concrete, is made of limestone and other materials. Once it is heated in an oven, it’s crushed into a fine powder and bagged for use.
Concrete is a mixture of portland cement, sand, gravel and water. Portland cement comes from limestone rock that has been crushed to a powder. During the manufacturing process of portland cement, carbon dioxide is released into the atmosphere. One tonne of portland cement requires one tonne of fuel to fire it in the kiln and produce one tonne of clinker (the hard substance that forms inside the kiln during firing).
Concrete structures have a long life-span with very little maintenance needed over time. Concrete will last indefinitely under water as it is not affected by chemical or biological activity. Concrete doesn’t rust away like steel so there’s no need to replace any damaged metals.
Hydraulic cement sets by reacting with water. Portland cement is hydraulic cement made by finely pulverizing clinkers consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an interground addition.
The hydration products include various calcium silicate hydrates and calcium hydroxide. It is not uncommon for the hydrates to include small amounts of other constituents, such as aluminum and iron compounds. Some scouring of the aggregates may occur during mixing, resulting in minor loss of surface area.