Concrete is probably the single most important construction material in the world today. According to the Global Cement and Concrete Association, about 1.8 billion cubic meters of concrete are produced each year worldwide. For reference, if these cubic meters were stacked on top of each other it would be enough to build almost 5 towers reaching the Moon. The amount of concrete the world produces is really mind boggling!
However, despite its incredible versatility and success, there are a lot of things you might not know about concrete, which can help you understand the ins and outs of this material. For example, what do you know about the history of concrete? What does it consist of? What does concrete look like? All these questions and more will be answered in this article about basics of concrete!
Concrete history spans over thousands of years, from the time of the Egyptian Pyramids to present day mega structures. Concrete has been used for many amazing things throughout history, including architecture, infrastructure and more. There has been historical evidence of concrete dwelling structures, underground cisterns and storage containers dating over six thousand years ago. Ancient Romans have built impressive structures out of concrete that survived even until the present day.
Modern concrete production become widespread in the 19th century when portland cement has been developed. The invention of reinforced concrete has further popularized concrete as a go-to material for large structures.
In the 20th century, concrete is used to build most of the world’s bridges, buildings, roads, and other infrastructure. However, as the 21st century has approached, there has been a shift towards using concrete for the production of more environmentally friendly products. This shift can be seen in the construction of eco-friendly homes, such as those built with recycled materials, or in the development of new technologies for making concrete that use less water and are therefore more environmentally friendly.
Portland cement is considered as the key ingredient for creating concrete because it is able to bind together the other ingredients in the concrete mixture and make the structure solid and strong.
Other common materials that are added into the concrete mix to improve the strength of the final product include aggregate stone and sand. However, even with the addition of these ingredients, concrete can still be brittle and break easily. That is why steel reinforcement is also often required.
Modern concrete also has additional chemicals to give the desired properties.
The list of the most common admixtures:
- Accelerators for faster curing time
- Set-Retarders for slower curing time
- Plasticizers to make the mix more fluid and workable
- Corrosion Inhibitors for the use in the areas exposed to salts
- Water Reducers to keep the desired water to cement ratio
- Shrinkage Reducers to control cracking
- Air-Entrainment for improved resistance to freeze-thaw cycles
Modern concrete may consist a number of ingredients ranging from aggregates to chemicals. The manufacturers are able to give concrete all kinds of the desired properties. The research teams are constantly working on improving concrete manufacturing formulas for the most efficient products.
Concrete is a versatile building material which can be used in many different ways. One of the biggest advantages over other building products is that it starts as a liquid and once solidifies it becomes as hard as a rock. It can be molded into a variety of shapes from slabs and columns that everyone is used to seeing to less common such as pipe, countertops and sinks.
The properties of concrete also make it a very durable building material. Concrete is extremely resistant to damage caused by impact, it can stand up to extreme temperatures and forces over time. It also has the ability to resist most chemicals and elements.
Rebar is an excellent way of reinforcing concrete structures and buildings. It provides a strong foundation for concrete structures. Reinforcement also adds strength to the concrete. It prevents cracking and allows the concrete to stand higher loads.
Most of the concrete ingredients are locally sourced and have a relatively small environmental impact. Cement, however, carries a much larger impact. If cement were a country, it would be the third largest emitter of greenhouse gases on Earth, after only China and the United States. It is estimated that approximately 150 tonnes of cement is consumed each second globally.
Cement production accounts for as much as 7% of global greenhouse gas emissions. That’s more than the combined emissions of the entire European Union and India, behind the emissions of China and the US. As urbanisation continues to grow around the globe, especially in developing countries, the environmental impact of this elementary building material is only likely to increase.
In order to manufacture one tonne of cement, the process of firing to 1,400C produces roughly one tonne of CO2. This chemical reaction, which has stayed unaltered since cement was first manufactured over 200 years ago, is responsible for 70% of the sector’s emissions. The remaining 30% comes from the energy used to fire the furnaces themselves.
There are many ways in which this material, essential for global housing, construction and infrastructure, can be made less harmful to the environment. Concrete recycling is the most straight forward approach at the moment. Old concrete is extracted, crushed and reused as an aggregate in the new concrete mixture. The research on how to further improve the environmental impact of the concrete industry is still very much ongoing.
Importance of Concrete
Concrete material is a truly versatile construction product for which there is no viable alternative at the moment. Its versatility makes it easy for the construction companies to use it for building roads, highways, sideways, garages, and any other structure. Its strength can be modified according to the construction requirements. It can also be molded into different shapes and sizes to create unique designs. The cost effectiveness simply cannot be beaten in the current environment.
Concrete is certainly not without its drawbacks but it still remains one of the most important materials that humanity has at its disposal.