THE BASICS OF SHOTCRETE

Shotcrete is a method of applying wet-mix concrete shot out of a hose at high velocity to an overhead or vertical surface. The whole cement-sand-aggregate blend is already mixed with water when it arrives in a ready-mix truck.

When hardened, shotcrete’s properties are similar to conventional cast-in-place concrete. However, placing it results in an outstanding bond with most substrates and allows you to create complex forms and shapes. In addition, shotcrete is more economical and requires less formwork than cast-in-place concrete.

While shotcrete applications are almost limitless, these are some of the most common applications.

Restoration

Frequently, shotcrete is used for the repair and restoration of reinforced and nonreinforced constructions. Common structures include:

  • Bridges
  • Parking garages
  • Dams
  • Reservoirs
  • Sewers

Ground support

Shotcrete is the preferred method to stabilise earth and rock excavations effectively. It offers several advantages over traditional timber and steel shoring when used to stabilise soil for excavation in tunnelling and mining.

Construction

Shotcrete is often used for the construction of several structures, including foundations, tanks, and domes. It’s preferred for minimising costs and the ability to construct curved, straight, or irregular surfaces and structures.

Recreation

Swimming pools and skate parks have many curves, making shotcrete the perfect flexible application for a durable, watertight, economic, and attractive result.

Tanks

Shotcrete tanks can be used to store a variety of liquids like wastewater. In addition, since the 1950s, shotcrete domes have been built in various sizes ranging from small shelters to vessels of more than 60 metres.

Architecture

An increasing number of architectural applications are created with shotcrete, thanks to its economy and versatility. It’s ideal for intricately formed structures, from buildings to landscapes. In addition, designers, architects, and contractors choose shotcrete for construction.

Contact Shotcrete Africa for details

Shotcrete is an excellent alternative to conventional concrete and has various application options. If you would like to know more about shotcrete, get in touch with a representative from Shotcrete Africa today.

THE ADVANTAGES AND USES OF SHOTCRETE

Shotcrete is a mixture of cement, aggregates, and water conveyed through a hose and pneumatically projected at high velocity, usually reinforced by steel rods or mesh or fibre.

Shotcrete is becoming increasingly popular among contractors and builders. It offers several advantages, and its application is highly economical and flexible.

Compared to regular concrete, shotcrete is more durable and imparts buildings and construction with higher mechanical strength. In addition, shotcrete structures are less porous and have a high bond strength. This reduces the construction time and cost.

Shotcrete is ideal for water retaining structures like river walls, reservoirs, water towers, aqueducts, dams, canal linings, swimming pools, irrigation, etc. In addition, tunnelling and underground mining activities contribute to the continued growth prospects of the shotcrete market.

Other uses include:

  • Supporting excavation foundations in combination with rock and soil fixing techniques in rock slopes.
  • Stabilising debris flow to protect channel linings and improve bridge safety.
  • Rehabilitating bridges, silos, and other reinforced concrete structures.
  • Restoring deteriorating piers, bulkheads, and other marine constructions.

BENEFITS

  • Shotcrete requires less formwork, making it more economical than conventional concrete.
  • A small space is required for construction.
  • Due to its high cement content, shotcrete is durable.
  • Shotcrete has low permeability and is resistant to fire and mould.
  • Shotcrete can easily be applied to irregular surfaces and hard-to-reach areas.
  • Shotcrete provides excellent corrosion resistance.
  • It is frost resistant.
  • Shotcrete has high initial strength and can reach 21N/mmwithin 24 hours.

There are a few disadvantages to shotcrete. This mainly relates to the need for expert and skilled operators to ensure proper placement and weather conditions. A strong wind will reduce the deposit energy, and rain could trigger slouching.

CONTACT SHOTCRETE AFRICA FOR DETAILS

In addition to its benefits in the building, construction, and mining industries, shotcrete is an excellent alternative to unstructured superstructure and substructure repair.

If you would like to know more about the shotcrete process and our expertise, get in touch with a representative from Shotcrete Africa today.

SHOTCRETE: AN IMPROVED APPROACH TO PLACING CONCRETE

Concrete is nothing new to us, but that doesn’t say much about the wide array of approaches that can be taken when laying it.

While the materials and qualities of a concrete mixture have a lot to do with the quality and strength of the finished structure, there is something to be said about how the approach to placing concrete can result in a better or worse structure.

Wherever concrete is being laid, there is a need for a finished structure that is strong, is not porous, can be completed in good time and fosters the best possible bond between the old concrete and the new material being laid over it.

Getting the most out of these qualities requires the right approach, and if you have been wondering what that approach ought to be, then you should find out more about an approach to laying concrete called shotcrete.

In this article, our shotcrete specialists will take an in-depth look at what the process involves. We will do this by first taking a look at what exactly the process it, how it differs from standard concrete pumping methods, where you can see it being used, as well as how the process can benefit you, no matter what kind of construction you are working on.

WHAT IS SHOTCRETE?

Shotcrete is not a product or a material, but rather a process for applying concrete mixtures to structures.

In a nutshell, the process takes a pneumatic approach to apply concrete that sprays the mixture directly on to the frame that it is being applied to.

While the process does require specific machinery and skillsets, it offers a number of benefits over standard concrete pumping, we will explore these in more detail further on.

During the process, concrete is sprayed to the structure at a high velocity. This is most commonly done to reinforce mesh, fibres and steel rods; but it also has a number of other applications.

HOW DOES SHOTCRETE DIFFER TO STANDARD CONCRETE PUMPING?

With this in mind, it is fairly easy to see how the shotcrete approach differs substantially from any other approach. And is a technique that has been around since the early 19-hundreds, it has become one of the most refined and effective approaches to laying concrete.

So, let’s take a look at a few of the key differences between the shotcrete technique versus standard concrete pumping.

These include a final product that has enhanced strength, an increase in permeability, improved durability, and a better fit for harsher conditions.

ENHANCED STRENGTH

The differences in strength between poured concrete and shotcrete are fairly substantial, which renders the shotcrete approach well suited to demanding jobs.

Poured concrete, for instance, boasts a compressive strength of between 2500 and 3000psi, which is quite impressive for many situations.

The shotcrete approach, on the other hand, has a compressive strength of well over 4000psi, affording it far more strength than poured concrete.

INCREASED PERMEABILITY

Because of the pneumatic approach used to spray concrete on to surfaces during the shotcrete approach, concrete applied in this way is far more permeable than poured concrete slabs.

To say that it is permeable basically means that moisture and gasses pass through it more easily.

This means that the concrete is better protected against water damage, while air that passes through the structure is actually filtered out to reduce indoor pollutants in the structure.

IMPROVED DURABILITY

Due to the fact that shotcrete allows for better strength and permeability, this approach also results in concrete that has better durability than poured concrete.

It will take less damage and wear over time, and will easily withstand damage from harsh weather conditions.

This, for many contractors, makes the shotcrete approach all the better than pouring concrete.

BETTER SUITED TO HARSH CONDITIONS

All of the above differences between shotcrete and poured concrete make this particular approach much better suited to particularly harsh conditions, such as those found in the mining industry.

The resilience and reliability of shotcrete structures are essential qualities in any harsh environment since they ensure the safety of personnel, machinery and facilities in such settings.

This isn’t to say that poured concrete isn’t ever suited to such conditions.

But when you compare the differences in its structural integrity to those structures erected through the shotcrete approach, it is easy to see which of the two is superior.

WHERE IS SHOTCRETE COMMONLY USED?

With the above differences making an apparent distinction between the two approaches, you might be wondering whether the shotcrete approach is commonly taken.

In almost all instances where concrete needs to be applied or repaired, shotcrete is always a good call.

But here are some of the most common uses for the shotcrete approach:

APPLYING STRUCTURAL CONCRETE

Applying structural concrete over vertical mesh or frames is a common practice in the construction industry.

In such settings, the shotcrete approach provides a crucial way to lay concrete in an even and controlled way.

It also makes for a far more efficient way of applying structural concrete thanks to its convenience, which can make all the difference on, particularly large structures.

Additionally, the shotcrete approach allows the structure to be given additional structural strength.

CONCRETE REPAIR

Where older concrete needs to be repaired, spraying concrete over the old concrete provides an excellent and efficient way of bringing it back to life.

The shotcrete approach is particularly effective when bonding older and newer concrete thanks to pneumatic spraying, which makes it one of the best approaches for repairing concrete structures. Or slabs.

WATER-BASED STRUCTURES

The shotcrete approach also results in a final structure that is far less porous than even vibrated mixtures that shake the air out after laying.

This makes more airtight and waterproof, which is great news for those who want to erect water fountains, install swimming pools or build ponds.

It is also frequently used in marine applications because of the non-porous results of the shotcrete approach, which forms an excellent base for waterproofing.

TUNNELS

Due to the additional strength that the process provides, as well as its ability to spray concrete in hard to reach or overhead areas, the shotcrete approach is one of the best to take when constructing tunnels.

Tunnels are highly reliant on their structural integrity when it comes to their viability, lifespan and safety.

Because of this, the additional strength, durability and permeability offered by the shotcrete approach make it perfect for application in tunnels.

LANDSCAPING

While strength and durability are what set shotcrete apart in other applications, its malleability and the way that the mixture can be worked also makes it an ideal approach for just about any type of landscaping.

Shotcrete structures can be manipulated for a smooth, sleek finish that modernises its surroundings, but at the same time, it can take on the natural appearance of rocks or clay to give a landscape a more sculpted, natural finish.

These are, of course, just two examples of how it can be used for landscaping, there are a lot more, however, and your options are really only limited by your imagination.

WHAT ARE THE TOP BENEFITS OF USING SPRAYED CONCRETE SERVICES?

Now that we have had a look at what the shotcrete approach is, how it differs to pouring concrete, and where the technique is most commonly used in construction, let’s take a moment to explore the many benefits that you can glean from using this approach.

These benefits are numerous, so let’s just concentrate on the most common of them.

These include superior efficiency, the cost-effectiveness of the approach, the provision of added strength and durability, a reduction in porousness, and the ability to lay concrete in difficult to reach areas.

A MORE EFFICIENT APPROACH

In any professional construction project, there are fairly strict deadlines. And in a world where time is money, and a solution that can save you time is something worth looking at.

One of the best things about the shotcrete approach is that it requires little to no formwork to be completed, which often takes up the bulk of time taken to lay concrete in any other way.

This means that fractions of the time can be cut off of construction when shotcrete is used to apply concrete, eliminating the risk of delays and getting projects completed in a better time.

COST-EFFECTIVENESS

Shotcrete mixtures are made up in fairly large batches at plants, from where it is delivered to the sites it is being used in, ready to be applied.

This makes it a fairly cost-effective option for contractors. There is something to be said, however, about the fact that shotcrete may need more maintenance efforts at an earlier stage of its life than other methods might.

But when compared to how much more cost-effective it is to conduct, it is easy to look past the raised need for maintenance.

ADDED STRENGTH & DURABILITY

As we have mentioned before in this article, shotcrete generally produces structures with better strength and durability thanks to the increased compression strength that it offers.

This makes it well suited to a range of applications that other methods might not be right for but also ensures stronger structures that last longer.

GETTING TO HARD TO REACH AREAS

Because shotcrete delivers concrete to surfaces using a method that pneumatically sprays it on to the surface, it is also an excellent option for those who need to lay concrete in hard to reach spaces.

High areas, tight spaces and awkward angles do little to stand in the way of shotcrete’s effectiveness, making it highly beneficial for any complicated construction tasks.

FINDING THE RIGHT SHOTCRETE SPECIALIST FOR YOUR NEEDS

After reading through these benefits, you may be tempted to opt for assistance from a shotcrete specialist.

But before you go off and sign up for any services, there are a few questions you should ask yourself about the contractor in question.

Remember that not all sprayed concrete services are made equal, so be sure to be thorough when answering the following questions:

HOW EXPERIENCED IS THE TEAM?

Experience counts for a lot in just about any construction task, and shotcrete is no different.

The more experienced the team is, the less likely they are to waste materials, make mistakes or conduct sloppy work.

Of course, more experience often comes at a higher price, so you might need to balance the two.

However, you prefer to do it, it is never wise to compromise on quality just to save a few pennies.

WHAT ARE THEIR CUSTOMERS SAYING?

Find out what their previous customers are saying about their services. Take a look online by Googling their name, checking to see if they have a social media profile, or by taking a look at websites like Hello Peter.

Even with the best contractors, you may find one or two unhappy customers, so don’t let a single bad review put you off.

If there are tonnes of them, however, you should probably look elsewhere.

CHECK EXAMPLES OF THEIR WORK

Contractors who are proud of their work are always happy to show it off. So be sure to ask the contractor in question whether or not they have examples of their previous work.

This will give you a first-hand account of what the finished product will look like, and whether or not the contractor is a good fit for you.

CONTACT SHOTCRETE SOUTH AFRICA FOR DETAILS ON OUR OFFERS

Are you looking for trusted sprayed concrete services from specialists that you can rely on to get the job done right?

Be sure to get into contact with a representative from Shotcrete South Africa today, or visit our website for details on our offers.

WHAT YOU NEED TO KNOW ABOUT SHOTCRETE

Shotcrete is when high performance concrete or mortar is shot through a hose at a surface at very high speeds.

The concrete is sprayed creating very dense layers up to the thickness that is required. Shotcrete is perfect for domes, tunnels or any round shapes. Shotcrete has been evolving since the early 1900s.

Shotcrete is extremely strong and can not only be used for protecting surfaces but also for renovating existing structures.

Structural Shotcrete

Structural shotcrete is used for its quick turnover, projects are completed much faster, concrete can be applied to areas larger than 2m per day. Faster application results in lower cost projects due to lower labour costs.

Concrete Repair

Using shotcrete for repairs on existing project is the most cost saving and effective method of applying repairs.

Support and Stabilisation

Shotcrete can be used as a support method in many different industries. In the mining industry it is often used to support the openings or to stabilise unstable slopes near highways, houses or where needed.

Silos

Silos can be returned back to its original state, just as secure as when originally built. Carbon fiber is often used in conjunction with shotcrete in its application. The carbon fiber aids in the strength of the silo, carbon fiber also has a longer shelf life.

Recreational Purposes

Shotcrete is often known for its use on large construction projects, but it is also used in some smaller projects. Skate parks use shotcrete to form ramps and half pipes, shotcrete can be used in zoos to create fake rock features, or it can be used in natural swimming pools.

Get all your shotcrete needs at Shotcrete Africa

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