The most common type of buildings that you see whenever you go out are concrete frame structures. As the name suggests, these buildings have a frame that’s made entirely out of concrete, with the vertical parts of it being called columns and the horizontal parts being called beams.
When it comes to these structures, the columns are the ones that have load bearing properties and if a beam were to be damaged in a building, it will affect the column and therefore increase the risk of the entire building collapsing.
Concrete is also known as RCC which is basically concrete that contains rebars or steel bars. This combination is the best for building most structures these days since steel is extremely strong in tension and concrete is extremely strong in compression.
Making reinforced concrete is not hard at all, but first of all a mold needs to be made which gives the concrete the desired shape for the project you're working on. Next, you'll have to take a good look at the drawings made by the engineer to place the rebars properly and then tie them using wire.
When the steel is properly tied up, the builder will need to prepare the concrete. He does so by mixing stone chips, sand and cement in a wide range of sizes, but he also adds water in the cement mixer and then, when ready, the liquid concrete is going to be poured into the formwork.
It's very important that the right amount of each ingredient is mixed in order to make sure that the concrete is going to have the right consistency and strength when it dries up to ensure the building won't crack or collapse at the first earthquake.
While different concrete mixes are used depending on the project, in general standard mixes are used. To offer some examples of such mixes, they include M40, M30 and M20 concrete mixes and in this case, the number refers to the concrete's strength in Newtons per square mm.
What this means is that M3 concrete has a compressive strength of thirty Newtons per square millimeter. Keep in mind that the maximum aggregate size can also be specified in the standard mix. So for instance, if an engineer were to specific M30/20 concrete, ten what he means is that the M thirty concrete has to have a maximum aggregate size of twenty millimeters.
So to sum things up, a concrete wall structure is basically made up of connected frame members that are very well connected to one another. When it comes to steel structures, hinge connections are the ones which are used most, yet when it comes to the concrete frame structures, they feature connections in ninety nine point nine percent of the case.
Due to the fact this frame will eventually become really strong, it can and will resist the wide range of loads which are undoubtedly going to act on a construction during its lifespan.
Some Examples of These Loads are as Following:
This refers to the building's downward force that comes from its weight.
This refers to the building's downward force that comes from the weight of its occupants, but also their possessions. The loads can vary if the building is an industrial, office or residential construction. For residential buildings, the minimum load is around two hundred kilograms per square meter.
Generally occurring in bridges, these loads are created by traffic, such as accelerating and braking loads.
These buildings are designed so they can withstand extreme conditions occurring once every one hundred years. These kinds of buildings will therefore withstand wind forces of about one hundred and fifty kilograms per square meter.
When an earthquake takes place, the building will be shook both vertically and horizontally which may cause it to fall apart. The thing is that if the building is very heavy, then its chances of collapse are much higher.
Since the concrete frame is resting on the foundation, the earthquake's force will be transferred from the building onto it and finally to the ground.
Other Essential Components of Concrete Frame Structures:
When it comes to high rise buildings, you should know what shear walls are very important elements. So basically, they are very big columns which can be as long as 9-10 feet and as thick as 16 inches.
Because of their size, they appear to be walls and not column. The reason they're integrated in a building is because they deal with the horizontal forces that act upon the building, including the forces generated by earthquakes and winds.
A building is also subjected to vertical loads which are usually due to gravity. The good news is that these types of loads are also carried by the shear walls, however, it's essential that you understand these walls will only be useful for handling horizontal loads in a single direction. Therefore, given their function, you won't actually find these walls built into low rise buildings.
As you may expect, each high-rise building will have elevator and the elevator shafts are basically vertical boxes that allow elevators to move down and up. In general, elevators are enclosed in their own box made of concrete. But what you don't know is that the shafts are also excellent structural elements that carry vertical loads and help resist horizontal loads.
Walls in Concrete Frame Buildings
One thing you need to know about concrete frame structures is the fact that they are not only economical, but they're also very strong. Because of that, you can basically use any type of wall material with them and if you want to lean towards the heavier options, they include stone, concrete blocks, but also walls of brick.
On the other hand, lighter options may be a good idea, deepening on your preferences and needs and some of them include wood studs covered with sheeting material and masonry walls of brick.
The truth is that most of the times when concrete or brick blocks are used, the entire surface will have to be plastered using a cement plaster. This helps form a long lasting, but also very durable finish.
Cladding of Concrete Frame Structures
One of the best things about concrete frame buildings is that you can easily clad them with just about any cladding material. Some of the most popular ones include ceramic facades, stone sheets, but also aluminum panels and glass. Since these types of buildings can be designed for heavy loading, you can also choose to clad them in stone, brick or solid masonry walls.