Last Updated on The astronomical consumption and the highly versatile manner of usage have led to the emergence of many different types of concrete materials. One of these popular types is architectural concrete.
Many builders and professionals in the industry often ask questions about what is architectural concrete construction, its usage, technical specifications, and its benefits. This article will explore all this information and more regarding architectural concrete.
What is Architectural Concrete?
Architectural concrete is the type of concrete that is applied on surfaces that stay in view. This concrete adds an aesthetic element as well as structural strength to the surface. Due to these requirements, architectural concrete requires special care in the selection of the elements of the materials.
History of Architectural Concrete
Concrete is not a recent material, and was used in different forms since as early as 1300 BC. Since 600 BC, concrete began to find vast applications in Rome. Many ancient Roman structures made of concrete stand even today, such as the Colosseum of Rome. However, the material went into a sharp decline after the Roman Empire diminished.
The discovery of Roman manuscripts in the 15th century sparked a new interest in the material. It received a further big push in 1824 with Joseph Aspdin inventing the Portland Cement.
How is Architectural Concrete Made?
Architectural concrete requires a number of materials, such as good quality cement, aggregates, water, and additives. The composition of each material is vital in the mix, as a slight change in ratio can alter the properties of the resultant structure significantly.
When these materials are mixed, the concrete goes through a long curing process. After curing, the surface is sanded and cleaned properly. Then it goes through a surface treatment which further increases the hardness of the material and protects it against the elements in the long run.
It is important that the forms and frameworks for shaping the concrete are kept to appropriate specifications and requirements. Therefore, the architecture provides constant feedback throughout the project planned, such as deciding on the shape and dimensions of the formworks.
How Does It Work?
Concrete by itself is formless, so it is made into the desired shape by using formworks. The process requires professionals such as designers to ensure that the formworks have the correct designs, and engineers that can ensure that the concrete has correct materials like releasing agents, pigments, aggregates, and cement, everything in the correct ratio. After curing, a wide variety of surface treatment processes can be applied to give the required texture to the architectural concrete surface.
What are the Materials Used in Architectural Concrete Construction?
Architectural concrete construction can require a number of materials based on the particular application. These materials involve:
- Steel
- Quartz
- Marble
- Granite
- Limestone
- Gravel
- Ceramics
- Glass fibers
- Plastic
- Plywood Panels (Exterior Grade)
- Non Absorptive Materials for continuous, true, and smooth architectural finishes
Cement For Architectural Concrete Construction
There are a number of options for which cement you can use for architectural concrete construction. Some of the guidelines to follow are:
- The cement should conform with the ASTM C 150, C595, C845, or C1157 requirements.
- Ensure that an adequate supply of cement is available to cover the entire project, especially if you are using special cement. This is because it is recommended to complete the project with cement from a single source.
- Architectural concrete requires certain properties, which require the addition of admixtures to the cement. Admixtures improve properties such as workability, durability, or surface finishing. Ensure that the cement you add the required admixtures to the cement during the mixing process.
What are the Benefits of Using Architectural Concrete?
There are many benefits of architectural concrete, such as:
- Versatility: Architectural concrete is highly versatile and can be used for all types of structural components.
- Durability: Architectural concrete has high durability. This not only leads to a longer life, but also means that you will be spending less on maintenance.
- Cost Effective: Due to the low initial cost, longer life, and low maintenance, architectural concrete is one of the most cost-effective materials for the construction industry.
- Impact Resistant: Architectural concrete can resist any type of mechanical damage from impacts as well as adverse natural elements.
- No Secondary Finishing Required: Architectural concrete eliminates the requirement to use any secondary coatings or paints. This saves not only the costs but also the construction time.
- Design Options: There are countless design, color, and finishing options for architectural concrete.
What are the Challenges in Using Architectural Concrete?
Even with all these benefits, there can be certain challenges to using architectural concrete. These challenges are:
- Carbon Footprint: Using architectural concrete leaves a massive carbon footprint in the environment. This is because of the high embodied energy of cement and the negative impact of other chemicals (like additives and admixtures) that go into the making of cement. In fact, when it comes to materials leaving the most carbon footprint industry, concrete ranks in the top three.
- Compliances: There are compliances and safety codes when it comes to using architectural concrete construction. These compliances can vary from location to location and the type of construction you are doing. You will have to research the applicable codes for your use case and make sure that your construction method fulfills those requirements.
- Skilled Team: To incorporate architectural concrete construction, it is important to hire a skilled team. This includes qualified structural engineers and experienced contractors.
- Time Consuming: Architectural concrete construction requires multiple steps such as mixing, pouring, and curing. The curing process in itself can be time-consuming and can take several weeks.
- Thermal Mass: The thermal mass of architectural concrete surfaces is very high, with a very low insulation value (R-value).
What are the Applications of Architectural Concrete?
There are many different uses of architectural concrete. Some of the applications of these materials are:
Residential Buildings:
Architectural concrete is an important element for residential construction elements that require a high focus on aesthetic appeal while maintaining the ruggedness of the material. These elements include:
- Driveways
- Footpaths
- Facades
- Balconies
- Other internal and external architectural elements
Commercial Buildings:
The high versatility of architectural concrete makes it usable for all kinds of commercial construction. This includes everything from large malls to round concert halls, from skyscrapers to boxed office buildings. Some of the commercial elements where it is applied are:
- Parking Garages
- Floorings (such as faux marble floors)
- Facades
- Curved elements in the building
Transport Infrastructure
Transport and related infrastructure are the lesser-known application of architectural concrete. In these applications, the high strength handling capacity of the architectural concrete plays a huge role. Some of the transport infrastructure elements that are made with architectural concrete are:
- Highways
- Retaining concrete walls
- Footpaths
- Bridges
- Tunnels
- Airports
- Car Park
- Street Benches and Other Furniture
What are the Different Formwork of Architectural Concrete?
The outcome of architectural concrete heavily relies on the formwork system in use. There are different groups of formwork systems, such as:
Walls Formwork System:
For vertical surfaces such as walls, concrete formulation of formwork is divided into two groups- panel formwork and girder formwork. Panel method is the most common type of formwork system for walls. One distinguishing feature of this method is that the joints between the panels leave a particular impression on the concrete surface.
Infrastructure Construction:
Formworks for infrastructure construction are generally used as support surfaces for making traffic route elements. Common examples of these elements are highways, tunnels, bridges, and retaining walls. Formworks in this application play a special role to create optical accents. The completed structure changes its appearance over time due to adverse weather elements.
Slabs Formwork System:
The slab formwork system is adapted from the girder formwork system for walls. These formworks are made out of metal or wooden girders. The formwork surface area is large with few panel joints, leading to a better surface character and finishes.
Column Formwork System:
For columns, the formwork system is very similar to those of the walls. Therefore, the choice is made between panels and girders formwork, based on the particular requirements.
3D Free Form Surfaces Formwork System:
In some niche construction projects, special 3D free-form structures are used for adding art and aesthetics. Traditional formworks do not usually meet the requirements of these niche construction. For this purpose, formworks are created based on a 3D building model of the projects.
Tolerances
- The tolerances involved in the formwork should conform to AC 117.
- The form face of every formwork should be high-density and non-vapor transmitting.
- The concrete surface created by the architectural concrete formliner, form face, and molds should match the design reference material.
Design Criteria
- The deflection of the face sheet should not exceed 1/400 of its span.
- The ties and bolts used in the formwork should be properly sized to withstand the pressure of the form designs.
What is Architectural Concrete Today?
In this day and age, these are the major focal points of architectural concrete:
Glass Fiber Reinforced Concrete (GFRC):
GFRC, as the name suggests, has tiny glass fibers added to the concrete to provide reinforcement characteristics. This concrete is one of the most common architectural concrete materials.
Precast Concrete:
Precast concrete panels provide a faster construction alternative that is cost-effective for large construction projects. These panels can be bought in any required surface finishes and custom shapes.
What are the Different Types of Concrete Surface Finishing?
Architectural concrete can be turned into a number of surface finishes. Some of the common options are:
- Brushed finishes
- Troweled finishes
- Formed concrete
- Form lined concrete
- Blast cleaned or mechanically tooled
- Patented imprinted concrete
- Polished concrete
What is the Best Alternative of Architectural Concrete?
Precast concrete offers the best alternative to traditional architectural concrete. The primary benefit of architectural concrete is the aesthetically pleasing surfaces it provides. Precast concrete as a building material already has this benefit.
Additionally, with precast concrete, you get ready to install concrete panels delivered to the job site. There is no requirement to wait for pouring and curing, which saves the construction project weeks in terms of time taken.
Conclusion
Architectural concrete is a demonstration of the exceptional quality of concrete and how it can be turned into appealing surfaces that still have the conventional strength of concrete. Architectural concrete, when used in modern forms such as precast or GFRC, can definitely be considered one of the leading construction materials of the present and the near future.
Frequently Asked Questions (FAQs)
Here are the answers to the most common questions regarding architectural concrete:
What is Architectural Concrete?
Architectural concrete is a specially curated concrete material for surfaces that are exposed to view. The primary elements of this type of concrete is the aesthetic nature and the ability to withstand outdoor conditions in the long run.
