In the last 100 years, foam concrete has been the subject of research and development and as a result has come into widespread use across the world as a vital, flexible, strong building material. Since the 1920s, people have used early versions of this material for insulation, and in the 1950s, 60s, 70s, and 80s there was a lot of research that led to the development of this material as a mainstream building material with a wide variety of applications. This material is different from ordinary, normal concrete in key ways. It is intended for specific types of uses and is produced through the use of special processes
What Is Foam Concrete?
Foam concrete is a specific type of concrete that is made up of cement, water, and air pores, as well as other materials. Some other names for this material include foamed concrete, foamcrete, cellular lightweight concrete, aircrete, or reduced density concrete. Other materials used in the production include pulverized fly ash, limestone, polystyrene beads, chalk, and sand.
Foam concrete is made up of a slurry of cement and water that is sometimes combined with other materials as well as a synthetic aerated foam. This synthetic aerated foam is created using foaming agents which are mixed with air and water utilizing a foam generator. Specific foaming agents are used to produce air bubbles that have a high level of stability and are resistant to the chemical and physical processes involved in placing, mixing, and hardening.
The properties of foam concrete are dependent upon the volume of filler type, cement content, foam, and material age. In order to be considered true foam concrete, the concrete mix must contain at least 20% foam content mixed into the cement slurry base but usually contains 30%-80% foam. Typically there is no coarse aggregate content that is used in production, and the correct technical term for this compound is foam cement.
Methods of Foam Concrete Production
There are two main methods used to produce foam concrete. Each of them is substantially different from the other. Some processes may be similar in nature, but there are steps taken for each method that are unique. The two different methods that can be used include:
- Inline method
- Pre-foam method
The inline method of foam concrete production utilizes two different types of systems; the wet system, and the dry system. Within the context of the inline method, the cement, water, other materials are mixed with a foam in the unit. The unit system controls used with the wet system are used to check the blending of the whole mix and these materials are typically more wet in nature. When using the dry system, materials are housed in silos and fed into a chamber in which these materials are added and blended to exact specifications.
The pre-foam method involves the process where the ready-mixed materials are brought by a truck to the construction site. The materials are injected into the truck and blended while the mixer is rotating. This is ideal for smaller batches and custom size batches that are made to order. This allows for the elimination of waste during the production phase.
Other Notable Facts About Foam Concrete
The strength and durability of this material are determined by the materials that are mixed in with it when it is being produced. As an example, if sand is included as a filler, the mix will be much stronger as a result. Foam concrete is highly desired for its excellent strength to weight ratio and resistance to shrinkage and cracking.
The use of foam concrete as a building material is known to reduce the overall building cost for many construction companies as well as provide a solid building material with many different potential uses. This material is also resistant to extremes in temperature, however, it is not as strong as normal concrete and cannot be used for all purposes.
The plastic densities ordinarily found in foamed concrete are between 400-1600 kg/m. It is a compound that flows under its own weight and is highly workable. The final dry densities are usually about 100-300 kg/m lower than ordinary concrete.
Why Consider Foam Concrete?
The lightweight properties of foam concrete make it a perfect alternative when large quantities of concrete are required, as it takes less manpower and energy to move the materials between locations. Handling the material is also easier as this material is much easier to cut than ordinary concrete.
Properties and Characteristics
The flexibility of this material makes it ideal as a filler for areas when wiring and the presence of pipes make it difficult to cut holes in the concrete. There are no toxic substances or fillers used in the production of this material and it is known as a stable, ecologically friendly compound. Because it contains up to 80% air, it has excellent sound absorption and fire retardant properties as well. There is a strong plasticizing effect involved in the material, and this is of the most sought-after benefits for using this compound. Until ten years ago, foam concrete was viewed as a weak, substandard material, but with the development of synthetic enzyme-based foaming agents, durability and strength have increased to the point where widespread use is now prevalent.
This material is not ideal for all construction uses, but there is a variety of situations that make using this compound the perfect solution. If you are using concrete for building foundations or for supporting beams you may want to use normal concrete as it is much stronger and will take the weight of these applications. However, for many different types of standard applications, foam concrete is used as a standard building material. This is thanks to the research and development of the 70s and 80s, which made this possible.
Uses Of Foam Concrete
There is a wide variety of potential uses for lightweight foam concrete. Lightweight blocks and panels are produced in many countries including Thailand, China, and India. Typically, these blocks are used to partition walls and also serve other uses.
The fluid nature of this material makes it ideal for void filling purposes. This material has been used to fill basements, storage tanks, old sewers, holes in the ground, and voids under roadways caused by heavy rain. It can be applied to the smallest of openings which makes it much more flexible, eliminating the need to dig up substantial areas and terrain, saving labor and money.
This material can be used as roofing insulation and this is probably the number one application of this material. It can also be used in the construction of concrete bridge abutments. The material does not impose large lateral loads which is an issue when using traditional, granular material.
Other Uses You May Find
Trench reinstatement is one more potential use that many construction companies have for this material. Use of foam concrete versus granular fill materials prevents settlement and damage to pipes in the road as well as avoiding cavities from forming that could cause further damage. Some of the other uses for this wonderful material include the building of the road sub-base which makes road structures less heavy. Wall construction using this material is a cheap and quick method of building across the world. Tunneling is also an application for this material as it is ideal for tunnel construction and repair and fills voids within tunnels while building.
Floor construction is another good use for this versatile material as foam concrete is ideal for building subfloors cheaply and rapidly. Lightweight precast blocks can be produced using this material with the addition of aluminum powder in an autoclaving process. Groundworks, fire breaks, and sound insulation are even further examples of how this lightweight material can be used in the construction industry.
Since its early uses in the 1920s and its further development in the modern world, foam concrete has gone through a lot of changes and will continue to evolve over time. There are many different potential uses for this valuable material, and since it costs less to produce and ship, many companies will choose to use it whenever possible. There are many other benefits in using this type of concrete including the ecologically-friendly nature of the material.
The production, distribution, and use of foam concrete will continue to thrive in the construction industry, and the versatile, flexible uses of this material make it possible to accomplish many tasks that were previously much more difficult. Building materials are all subject to technological advances in this day and age, and it is expected that foam concrete will also undergo additional improvements over time.
For those considering using this material for their construction projects, becoming educated in the properties and materials used in its production would be a wise way to further pursue the best way to understand and use it effectively. Although the production of this material is widespread across the world, the manufacture of foam concrete is big business throughout the USA.