Concrete is one of the most effective construction materials we’ve invented. While we have used concrete in construction since antiquity, it’s only recently that we have used it for most of our construction projects and infrastructure.
While concrete is durable, it needs much time to set up the steel reinforcements and formwork to mold it into the proper shape. In addition, adverse weather conditions like high temperatures or rain could cause delays if you’re mixing and pouring concrete on site. What if there was some way to fabricate concrete pieces offsite and assemble them when you start your project?
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Precast Concrete
The term ‘precast’ means the concrete gets mixed and formed offsite into different sections. Curing the concrete also happens in the same place and happens in a controlled environment, so you can rest assured that the pieces are as durable as they can be. They then get transported to the construction site, where you assemble the different parts to finish the project.
Benefits of Choosing Precast Concrete Pieces
Choosing to use precast concrete is a choice that many in the construction industry make mainly for the benefits it provides. Let’s go over a few of those benefits:
Best of Both Worlds
In some cases, a project’s engineering and architectural sides could be at odds with one another, mainly due to a difference in goals. While the architect’s primary concern is to enhance the aesthetic appeal of the building and its surrounding space, the engineer ensures that the building is strong enough to perform its intended role. Precast concrete could achieve both of these goals at once.
With precast concrete, manufacturers can use molds of different materials like fiberglass, timber, or steel. This quality allows precast concrete to have a variety of exterior finishes without compromising its strength.
Faster Turn-Around Time
Since you won’t have to pour much concrete on-site when working with precast concrete, you’ll have more time to focus on other duties, such as earthwork or adding more safety factors. In addition, you can work in various weather conditions without worrying about the concrete setting properly since the manufacturers completed this step for you beforehand.
Moreover, precast concrete plants can accommodate your prestressed concrete requirements. This factor allows the concrete to withstand heavier loads and reduce the number of load-bearing elements in the building, reducing your construction costs.
Thermal Performance
Concrete is naturally dense and takes much energy before it starts transferring that energy. This quality makes concrete perfect for creating thermal barriers between different areas. With precast concrete, you can incorporate other materials into the mixture. In addition, manufacturers can create a fire-rated wall slab and add fire-rated doors ideal for wall installations simultaneously into the concrete—saving you construction time while still adhering to local building regulations.
Drawbacks of Choosing Precast Concrete
Integrating The Structure
Regardless of the type of precast concrete piece you choose, you’ll still deal with the problem that it’s separated from the rest of the structure. Because you’ll have to attach the parts, you create joints that result in a structural discontinuity. You’ll have to account for these joints directly in the design of your building to prevent a disproportionate collapse.
A disproportionate collapse is a phenomenon where the failure of one component of a building leads to the gradual loss of other components — essentially creating a ‘domino effect’ with disastrous consequences. You’ll need to ensure there’s enough continuous reinforcement between each concrete piece to ensure that the loss of one section does not result in the total loss of the structure.
Creating A Solid Seal
To build with precast concrete, you’ll need to account for local stresses between each piece and the overall stress the construction must handle. Since each segment is separate, the connection between two walls or a floor and a wall will be less than 100% flush.
Once the building starts to move under lateral or vertical forces, the local stresses between each piece might cause damage to the different sections hence why a grouted joint to ensure that damage does not happen. Furthermore, the joint between each part is vital to ensure water does not leak into the structure and cause damage to the concrete pieces.
Final Thoughts
Precast concrete is a phenomenal building material when you want to deliver a high-quality result while still meeting stringent deadlines and building codes. You can rest easy knowing you can rely on precast concrete for a load-bearing element or a purely aesthetic facade as long as you incorporate these qualities from the start of your design.
