Concrete and Types of Concrete
Concrete is a construction material that has been used for centuries in the construction of buildings, roads and bridges. Concrete cement is made by mixing cement, fine and coarse aggregates and water. Here, the cement acts as a binder. There are other different binding materials that are used other than cement, such as bitumen for asphalt concrete used in road construction and lime for lime concrete.
Different types of concrete are available in Australian market today. When deciding which concrete mix to use, you’ve to consider several factors like your budget, the size of your project and the climatic conditions that the concrete will be exposed to.
Strength might be another determining factor when deciding which types of concrete to use. Plain concrete for example has a comprehensive strength of 10MPa, high-strength concrete has a comprehensive strength of 40MPa, and high-performance concrete has comprehensive strength of 55MPa or higher.
In this article, we’ll look at 18 types in detail in order to give you a more informed decision as to which one is best for your construction project.
Plain concrete is concrete that is not reinforced. It is made by mixing cement, water and aggregates (fine and coarse) and is mainly used for basement constructions, flooring, footpaths and paving.
Reinforced concrete is the same as plain concrete in terms of the materials used, the major difference is the addition of steel rebar which makes it much stronger. Reinforced concrete is suitable for skyscrapers and sidewalks.
Air Entrained Concrete
Air entrained concrete is concrete in which air bubbles are introduced on purpose so as to make it resistant to freezing or thawing. There are many air-entraining agents that can be used (resinous acids, petroleum acid salts, synthetic detergents), these air-entraining agents can be mixed in with the other ingredients during manufacture to produce a special type of cement called air-entrained Portland cement or they can be introduced under careful engineering supervision, as the concrete is mixed on job site. It is suitable for areas which are prone to freezing and it is also in road construction.
High-strength concrete is concrete that has a comprehensive strength of 40MPa or higher while normal strength concrete has a strength of between 20 and 40MPa. High-strength concrete is suitable for home maintenance and renovations.
Prestressed concrete is a type of concrete that is compressed “prestressed” during manufacture in a way that makes it strong and able to withstand strong forces. This type of concrete is suitable for use in industrial pavements, high-rise buildings, bridges, dams, tanks, nuclear containment structures and more.
Unlike standard concrete, precast concrete is produced in a controlled environment (commonly referred to as a precast plant), by casting it in a reusable mold and then curing it. Once it is ready, it is taken to the construction site and put into place.
Precast concrete is used within interior and exterior and walls, in agricultural settings like cattle feed bunks, in building and site amenities e.g. fireplace mantles, in retaining walls e.g. sea walls, and in sanitary and storm water management products e.g. manholes, to name but a few.
Lightweight concrete is a type of concrete that includes expanding agent and is not as heavy as conventional concrete. It is made by mixing lighter aggregate e.g. perlite or vermiculite in place of heavier aggregates with the concrete, which reduces the overall weight. Because it is light, it is used for protection like in insulating waterpipes, it is also used in the construction of rooftop decks and countertops.
Shotcrete, also known as gunite or sprayed concrete, is a mixture of sand (fine aggregate), cement, and water that is applied at high-pressure using a hose. It is normally reinforced with steel mesh, fibers or traditional steel rods and is mainly used in the construction of swimming pools.
Glass concrete is a type of concrete mix in which glass is used to replace the aggregate. Recycled crushed glass is mixed in with the cement and the end results are granite or marble like finishes, concrete that reflects light like a mirror, or colorful terrazzo. It’s mainly used in countertops.
Ready Mix Concrete
Ready Mix Concrete (RMC), is concrete that is mass-produced in a concrete plant by adhering to a strict engineered mix design. Ready mix concrete is usually delivered in either one of two ways. First, it can be delivered in a dry state by a volumetric concrete mixer and then mixed on site. The second way is whereby it is delivered by a barrel truck to the site in as concrete.
Polymer concrete is concrete that uses polymer as a binder instead of lime-type cements. Polymer concrete is composed of aggregates like limestone, quartz, granite, silica and thermoplastic polymer, specifically thermosetting resins because of its high thermal stability and resistance to a wide range of chemicals.
Polymer concrete is suitable for places that contain liquids and corrosive chemicals like swimming pools, drainage channels and sewers.
Pervious concrete is also known as porous pavement, permeable concrete, no fines concrete and porous concrete. It is made by mixing large aggregates, cement and water, and because it doesn’t contain fine aggregates, it is highly porous and allows water to pass through it.
Pervious concrete is therefore suitable for areas with light traffic, parking lots, greenhouses, pedestrian walkways and residential streets.
High-Performance Concrete is made from the same materials as those of traditional concrete, but the proportions are engineered or designed to provide durability and strength needed for environmental and structural requirements of a project. It’s comprehensive strength is 55MPa or higher.
Pumped concrete is concrete that is pumped to construction sites by either flexible hose or rigid pipe and discharged in the desired area. Pumping is mainly used in construction projects where large amounts of concrete work is required at greater heights and construction equipment or space is limited.
Limecrete also known as lime concrete, is a form of concrete that uses lime as a binding material instead of cement and it can be used as an alternative to cement concrete, in foundations, or to make a breathable floor. It is made by mixing natural hydraulic lime and sand or lightweight aggregate with just enough water to allow the material to be bound in the hand.
High-Density concrete, also known as heavyweight concrete or heavy concrete is concrete whose density is approximately 50% more than the density of conventional concrete and is mainly used for radiation shielding. It is mainly used in atomic power plants.
Vacuum concrete is a form of concrete in which excess water is removed before hardening takes place so as to improve the strength of the concrete. Its bond strength is about 20% higher and it can be used for repair works like resurfacing road slabs.
Stamped concrete, also known as imprinted or textured concrete is concrete that is embossed, patterned or textured to look like wood, tile, stone, brick, slate and is commonly used in patios, interior flooring, driveways, sidewalks and pool decks because it is more affordable than natural stone, long lasting, easy to maintain and has a wide variety of patterns and color choices.
What is the Most Common Type of Concrete?
There are many types of concrete available in the market today. However, plain concrete is the most common and most used type of concrete in construction. It is the most basic form of concrete which is prepared by mixing Portland cement, fine and coarse aggregates and water. It is mainly used in construction of basements, flooring and footpaths. Reinforced concrete, ready-mix concrete, lime concrete, prestressed concrete, precast concrete and lightweight concrete are also common.
What is the Cheapest Form of Concrete?
When it comes to cost of concrete, Shotcrete is the cheapest, it ranges from $50 to $75 per square metre. It is followed closely by plain concrete at $60 to $85 per square metre, according to HIPages.
Which Type of Concrete is the Strongest?
When it comes to strength, High-Density concrete is the strongest, its density is approximately 50% more than the density of conventional concrete and is mainly used for radiation shielding. It is therefore used in industrial settings like in nuclear and atomic power plants.
Which Type of Concrete is Best Suited in Australian Homes?
Whether you’re constructing a new home or renovating an existing one, there are different types of concrete that are available in the Australian market for domestic use.
For example, plain concrete can be used in basements. Air entrained concrete is suitable for areas prone to freezing. Limecrete can be used in foundations or to make breathable floors. Precast concrete is used within interior and exterior walls.
Reinforced concrete is suitable for skyscrapers and sidewalks. Stamped concrete is commonly used in interior flooring, driveways, sidewalks, pool decks and patios. Lightweight concrete is used in insulating waterpipes and glass concrete can be used in countertops.
So, there are several options to choose from depending on your location, budget, environment, size and type of project.