Precast Building Construction: What Is It and How It Works?

The need for more houses and buildings increases as the population increases. But building a house is a long and tedious process. If there was only a way to have your dream house in a fraction of the time it takes to build, not by building it from scratch but by putting it together like a giant logo. This is what precasting does. In this blog, we’ll explore the world of Precast, how it works, and its advantages and disadvantages.

What is Precast Building Construction?

Precast building construction is a process in which buildings are constructed using prefabricated concrete components. It is produced by casting concrete in a reusable mold or "form", which is then cured in a controlled environment. These components are produced in a factory setting and then transported to the construction site, where they are assembled into the final structure.

Why Choose Precast Construction?

Time

Precast concrete components can be fabricated off-site in a controlled environment, greatly reducing the time required for on-site construction.

Durability 

Precast concrete structures are typically much more durable than their traditional counterparts and require less maintenance over time.

Quality Control 

Precast construction often results in a higher quality product due to the controlled environment in which the components are produced.

Flexibility

Precast concrete components can be produced in various shapes and sizes, making them well-suited for several applications. Additionally, precast concrete can be easily customised to meet the specific needs of any project.

Environmentally Friendly

Precast concrete components are produced in a controlled environment, and significantly less waste is generated during construction. Additionally, precast concrete structures tend to have a longer lifespan, which further reduces the environmental impact of the building over time.

Pros and Cons of Precast Building Construction

Pros

• Reduced construction time
• Improved quality control
• Increased safety on construction sites
• Reduced noise and vibration during construction
• Reduced site disruption and environmental impact

Cons

• The weight of precast panels can require special handling and lifting equipment.
• Transportation of precast panels can be challenging due to their size and weight.
• Precast panel joints must be carefully designed to accommodate movement and allow for thermal expansion.

Types of Precast Elements Used in Construction

Prestressed Concrete Panels

Prestressed concrete panels are made by pouring concrete into a mold, and then applying high-strength steel cables to the wet concrete. The steel cables are then tensioned and anchored to create a strong bond between the concrete and the steel.

This type of precast element is very strong and durable, making it ideal for use in load-bearing walls or columns.

Reinforced Concrete Columns 

Reinforced concrete columns are made by pouring concrete around a metal cage or grid that contains reinforcing bars (rebar). The rebar adds strength and stability to the column, making it ideal for load-bearing applications.

Precast elements can also be made from other materials, such as wood, stone, or brick. These materials can create decorative elements such as cornices or parapets.

Installation Processes

Step 1: The precast element needs to be designed and engineered.

Step 2: Molds much be created to cast the concrete elements

• Depending on the size and complexity of the element. The molds can be,
• Reusable
• Disposable

Step 3: concrete is poured into the molds and it is allowed to cure.

Step 4: Once cured, the precast elements are removed from the molds and transported to the job site.

• Depending on the size and weight of the element, this transport can be done with a crane or other heavy equipment.

Step 5: The precast elements are lifted into place and connected using mechanical fasteners or grout at the job site. 

Step 6: Once the precast elements are in place, any exposed surfaces are finished with plaster or protective coating.

Case Studies of Completed Projects

Many completed precast building projects can be used as case studies to understand better how this construction method works. One such project is the San Francisco Federal Building, completed in 2007. This 18-story office building features a load-bearing precast concrete frame and facade, with interior partitions and column covers made of precast concrete.

Another notable precast building is the Comcast Center in Philadelphia, completed in 2008. Standing 975 feet tall, it is currently the tallest LEED-certified building in the United States. Its precast concrete core and floor system helped contribute to its green credentials.

The following are some other examples of well-known buildings that have been constructed using precast concrete:

• National Stadium - Beijing, China
• Petronas Towers - Kuala Lumpur, Malaysia
• Sears Tower - Chicago, USA (now Willis Tower)
• Taipei 101 - Taipei, Taiwan

Conclusion

Precast building construction has become a popular choice for construction projects worldwide with its many benefits. To learn more about recent trends and technologies in civil engineering, check the blogs and courses offered by Skill-Lync. We offer Post Graduate Programs in various domains like BIM, Structural design, etc., and the courses such as High-rise Buildings Design and Analysis, Bridge Design and Analysis. You can learn at your own pace, whether a beginner or experienced. Book a free demo session to know more! So what are you waiting for? Start your learning journey with Skill-Lync!