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 fine and coarse aggregates and water. Here, the cement acts as a binder. Other binding materials are used besides cement, such as bitumen for asphalt concrete used in road construction and lime for lime concrete.
Different types of concrete are available in the 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.
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 materials; the major difference is the addition of steel rebar, making it stronger. As a result, reinforced concrete is suitable for skyscrapers and sidewalks.
Air Entrained Concrete
Air entrained concrete is concrete in which air bubbles are introduced to make it resistant to freezing or thawing. Many air-entraining agents 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 prone to freezing, and it is also in road construction.
High-strength concrete has a comprehensive strength of 40MPa or higher, while normal concrete has between 20 and 40MPa. Therefore, 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 mould and then curing it. Once ready, it is taken to the construction site and placed. 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 stormwater management products, e.g. maintenance holes, 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 water pipes, and 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 applied at high-pressure using a hose. It is normally reinforced with steel mesh, fibres or traditional steel rods and is mainly used to construct 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 results are granite or marble-like finishes, concrete that reflects light like a mirror, or colourful 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 onsite. The second way is to deliver it by a barrel truck as concrete.
Polymer concrete uses polymer as a binder instead of lime-type blocks of cement. Polymer concrete comprises 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 suitable for areas with light traffic, parking lots, greenhouses, pedestrian walkways, and residential streets.
High-Performance Concrete is made from the same materials as traditional concrete. Still, the proportions are engineered or designed to provide durability and strength needed for a project’s environmental and structural requirements. As a result, its comprehensive strength is 55MPa or higher.
Pumped concrete is pumped to construction sites by either a flexible hose or rigid pipe and discharged in the desired area. Pumping is mainly used in construction projects where large amounts of concrete work are required at greater heights and limited construction equipment or space.
Limecrete, also known as lime concrete, is a form of concrete that uses lime as a binding material instead of cement. 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 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 to improve the strength of the concrete. As a result, 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 colour choices.
FAQs About The Different Types Of Concrete Mixes
There are many types of concrete available in the market today. However, plain concrete is the most common and most used type in construction. It is the most basic form of concrete, prepared by mixing Portland cement, fine and coarse aggregates and water. It is mainly used in the construction of basements, flooring and footpaths. In addition, reinforced concrete, ready-mix concrete, lime concrete, prestressed concrete, precast concrete, and lightweight concrete are also common.
When it comes to concrete, Shotcrete is the cheapest, and it ranges from $50 to $75 per square metre. According to ages, it is followed closely by plain concrete at $60 to $85 per square metre.
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. Therefore, it is used in industrial settings like in nuclear and atomic power plants.
Whether you’re constructing a new home or renovating an existing one, different types of concrete 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 water pipes, 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.
Different Proportions To Consider For Concrete Mix
As your construction project progresses smoothly, it’s important to consider the right concrete mix proportion. But, as the slurry gets prepared with cement, sand, and water, the ratio depends on the construction project. However, based on prior experience, the building codes offer standard ratios for onsite construction. If you are worried about quality, you should opt for premix concrete in Brisbane from Reocrete. But, if you are not sure about the ratio, you should read ahead to learn more about the proportions.
Materials Used For Preparing Concrete
Among the basic materials, concrete always has cement as its constituents. While shale, limestone, and other ingredients are burnt to form clinker, the grinder grinds the lump to obtain a fine powder. You may come across blended cement at some sites; however, this is ideally used for masonry work, ideally for plastering. Apart from cement, aggregate and sand are also major constituents. The ingredients enhance not only structural integrity but also increase compressive strength.
Different Types Of Proportions
- Nominal Mix ratios: Many years ago, the ratio of the constituents for concrete was based on the amount of cement and aggregate. Since this was considered a fixed ratio, such ratios were known as nominal. Ideally, the nominal ratio is 1:1.5:3 for M20 grade concrete and 1:2:4 for M15 concrete. To learn more about concrete prices in Brisbane, contact Reocrete today!
- Standard Mix ratios: As the contractor may vary the nominal ratio, the overall constitution may differ to some extent. Even though the ratio may enhance strength, the cement may not suit onsite construction work. Hence, concrete is based on a standard ratio to maintain minimum compressive strength. While you purchase concrete, you may come across different grades like N20, N50, N32, and N25. But, for grades more than 50, the contractor may require special class concrete for the work. Regardless of the concrete mix, every grade is different concerning its compressive strength.
- Designed Mix Ratio: When dealing with a Designed Mix Ratio, an experienced professional determines the precise proportion of the constituents. Moreover, concrete suppliers in Brisbane may follow a rational approach to figure out the proportion with the unique characteristics of the materials. It’s completely normal to use standard or nominal mixes for short-duration jobs. The ratios, in this case, don’t matter when there isn’t any need to carry out control testing.
Finally, to increase the strength of hardened concrete, it’s important to maintain the water to cement ratio; fine aggregate can be added only when preparing a sticky mix.
Concrete Mix Design And Concrete Mix Ratio
A concrete mix is a mixture of cement, sand, and gravel that becomes hard after it dries. That’s the easy, simple part. But it turns out that it is all a bit more complicated than that.
Cement is used to construct many things in the world today. Concrete mixes are created with different ratios for different purposes. Some mixes may be stronger than others, depending on what you need them for, but they all have some common ingredients. In this post, we will discuss how concrete mixing ratios work and the main ingredients of a concrete mix?
Concrete is one of the most versatile building materials used today. It can be used for everything from sidewalks to skyscrapers, and it’s also a great material for home improvement projects around your house. Unfortunately, all these purposes require many different variations of concrete mixes with different ingredients and ratios.
All concrete mixtures have four main criteria to aim for:
- Workability: Needs to fit the context – such as being pumpable. Issues like viscosity are key to the workability of concrete.
- Strength: Need enough but not too much as it doesn’t help and may detract from other needed qualities. The water controlled it to cement ratio, aggregate choice, and bond effectiveness between paste and aggregate.
- Durability: Is it going to perform over the service life of the concrete?
- Economy: Is it cost-effective? The most expensive element is the Portland cement. Reducing cement reduces cost.
The art of concrete mix design and ratios is to create the right collection of these properties for a given concreting job. For example, if the concrete needs to be pumped on top of a building, making a slab or a bridge, each scenario will require a different way to design the concrete mix. Concrete mix design is a balancing act: If you push any one of the four criteria too much in one direction, it will cause a problem in another one of the criteria.
The Concept Of Modulus
The term “modulus” refers to rigidity (resistance to deformation or stiffness). In concrete mixture design, the modulus is usually an engineering-oriented factor assigned to express the durability of a concrete mix. When higher values for steel fibres are used in a given composition, it becomes necessary to have higher values for the modulus. In general, high compressive strength mixes tend to have higher moduli – which typically means that they will also be more brittle and susceptible to cracking than lower compressive strength mixes. Mixes with lower values of shear and flexural strengths need not be highly rigid because they are more likely to fail from deformations rather than
Paste And Aggregate Make Cement
With all the possible variations, figuring out what type of mix you need can be confusing at first glance. It comes down to two basic things: A paste and aggregate. These are combined to form cement. Typically, the cement paste is made from cement powder, and water, when added together, becomes a paste. Aggregate can be fine or coarse, or a mixture of both, and is added to the paste in quantities designed to give it the material qualities of strength and durability needed once it is fully hardened.
Two Stages Until The Final Product
Concrete has two stages. Fresh wet concrete must be workable to be laid properly, and hardened concrete is the form it takes once it has been left to cure and harden over some time.
Getting The Concrete Mix Ratio Right: Mixture Design
To make a strong and durable mixture, there must be the right proportion of water, cement, gravel, and sand. A small amount of air is also important for the correct outcome. The ingredients should also be proportioned correctly and mixed well. Mixture design is crucial for achieving a result. For example, concrete which contains more than 20% cement will be hard and brittle, while a mix with less than 15% water would not cure properly, becoming poor quality concrete.
It is important to be aware of the importance of an optimal concrete mix ratio for the purpose you need it to have a long-term functional use; otherwise, they could end up with a very expensive puddle that will not last more than six months.