Gunite is a mixture of dry sand and cement that is hydrated and blown through a hose (or “gun”). Gunite is similar to shotcrete, consisting of the same materials. The primary difference is that shotcrete is premixed, while gunite mixes with water as it leaves a hose.
Carl Akeley invented both compounds in 1907. He sought to create a form of cement for the ranged reinforcement of steel beams, trusses, and other structures. He invented both gunite and the “cement gun” hose. Today, builders use machines to aid this process in both small and industrial projects.
How is Gunite Different From Shotcrete?
Gunite and shotcrete are two terms that you will often hear either interchangeably or in succession. Both terms apply to varieties of sprayed concrete, and each consists of the same materials.
However, these two materials are not the same. The primary difference between gunite and shotcrete is how they are applied. Each substance has a unique preparation method and application process.
Concrete mixes are divided based on whether they are “wet” or “dry.” Gunite is a dry-gun or dry-mix concrete solution. As such, the mixture is hydrated at the hose nozzle before being sprayed onto a surface. The shotcrete process involves a wet-mix concrete solution. It is pre-prepared and propelled from the hose without any additional water.
Some sources use the terms interchangeably, but construction workers use both words where appropriate to distinguish between wet and dry materials.
When is Gunite Used?
Gunite has a variety of applications, including:
- Water tanks and concrete pools
- Artificial ponds
- Slope stabilization
- Hard rock mining and tunnels
- Ditches, channels, dikes, and dams
- Retention walls
- Structural reinforcements
The compound’s versatility is thanks to many of its unique properties. Gunite is thin, delicate, and bonds easily. It doesn’t require the complicated formwork of other concrete laying methods. Additionally, it sprays thinly enough to gently create curves for gunite pools, domes, and more.
Gunite is excellent for tapering or reinforcing sections of walls after several layers. Its thin liquid state before hardening conforms easily to various wall shapes. A pool builder will use gunite because it is watertight and rigid. As a result, it has a prominent advantage in projects that involve water features.
Advantages of Gunite
Unlike normal concrete laying methods, gunite accommodates any wall or surface. Consequently, it has uses in many specialty applications. The cement gun hydrates the mix as it propels from the nozzle. Upon hitting a surface, the gunite compacts, consolidates, and strengthens all at once.
A gunite coating on steel fiber creates reliable structural and ductile durability. The compound sticks to surfaces better than poured concrete and has lower permeability to prevent leakage.
It also has a lower aggregate size of about 3/8ths of an inch. A lower aggregate size means that gunite holds its shape better and resists erosion. This factor also makes it easier to manage.
Unlike poured concrete, gunite has a low shrinkage range of between 0.06 and 0.10 percent after 28 drying days. Lastly, the process is cheaper than other forms of concrete laying.
If you are considering gunite for a residential or commercial concrete project such as an inground pool, AM Construction can help. We use only the best materials and can deliver any quantity or quality of concrete that you need. We offer you a free quote just for calling, and we can work within your budget.
Call us today to learn more about gunite concrete projects, our services, and how to get started.