Concrete is almost ubiquitous in architecture and construction, where heavy-duty materials are needed. Over the centuries, concrete has become one of the most fundamental materials in modern architecture, leaving the rest of the building materials behind. Because of its outstanding load-bearing capacity, concrete is used for the foundations, walls and columns of buildings, whether industrial or residential.
History and applications of concrete dates back to antiquity. The Romans used so-called Roman cement (aluminium and silicon rubble) to build the roads, baths and famous aqueducts of their empire.
The Roman cement was made by preserving the volcanic tuffs of Vesuvius by adding lime to obtain a mixture that binds under water.
What is concrete really?
Building material, of course! But from what? Concrete is a a mixture of cement, water, sand and crushed gravel (i.e. pebbles).
Cement is a hydraulic binder that contains a powder made from the stone, which binds and hardens when mixed with water.
Thanks to the chemical bonds in this process, the cement has interesting properties that are used in concrete making.
The most common form of cement Portland cement, whose main raw materials are limestone and clay.
In cement production, raw materials are first crushed and dried, then mixed and heated together to produce clinker. This is then cooled and ground to the known powder consistency to produce cement.
A typical concrete composition 60-75% sand and aggregate, 15-20% water and 10-15% cement. The strength of mixed concrete is inversely proportional to the water-cement ratio.
Flexibility and durability steel bars can be increased by placing. When mixing concrete, care should be taken to use only the minimum amount of water necessary in the process.
When mixing concrete by hand in the traditional way, one of the most common mixing ratios is 1 shovel of cement to 3 shovels of gravel.
Easier with help
The biggest change in the history of concrete has been in the concrete mixing process. In the early 1900s, the mass adoption and use of simple concrete mixing machines was the greatest advance.
Did you know? The first concrete mixing machine was invented in 1846 by Joseph Aspdin of England.
Today, state-of-the-art concrete machinery ensures that the right proportions are always achieved.
As concrete can be used for a long time, it can lead to environmental degradation over time. For example, cement production is responsible for greenhouse gas emissions. Therefore, several sustainable solutions have already been developed, such as cement spraying during production, which reduces carbon emissions.
Throughout its centuries-long history, concrete has evolved and adapted to changing needs and is certain to remain a dominant building material for a long time to come.
