Precast concrete has increased in popularity in recent years for many reasons. Today, more and more contractors are choosing precast products, rather than casting concrete themselves on the construction site. However, precast concrete is not a perfect solution, and although it comes with many benefits there are also several disadvantages to its application.
How Are Precast Products Made?
The key to making precast concrete is using a controlled environment, rather than producing it on the construction site at which it is ultimately set to be used. This will usually be a factory specialising in the production of precast products, which create molds based on plans from the design engineer or architect that forms the basis of the element.
Concrete is then cast into the mold, which will be composed of a rebar cage in the shape of the desired element. Once casting is complete, the concrete will be cured within the factory using heat to harden the element, complete with any desired finish. Once the process is completed, precast elements are then transported to the site for use.
Advantages Of Precast Concrete
There are many benefits offered by using precast instead of site-cast concrete. The biggest advantage is that the finished product will be of a much higher quality than a site-cast option. As it is made in a highly controlled, regulated environment, precast products can be made at a consistently high quality, not affected by external factors such as weather. The controlled nature of the process makes it much easier for technicians to control the mixing, placement and curing of the material than it would be for someone on the construction site.
The next major benefit is cost. As precast concrete production uses a mold, costs can be greatly reduced when producing multiple copies of the same element. Plus, with the process being so controlled and consistent, each element will be exactly alike, eliminating potential wastage. Costs are reduced further due to the reduced amount of labour required to create precast elements, and you may be able to get a discount ordering materials in bulk.
Finally, precast concrete elements can be immediately installed on site without needing to wait for the curing process to finish. This makes it cheaper to install, easier to complete on schedule, and more efficient in terms of wasted time and space. It also typically requires less maintenance than site-cast alternatives.
In short, the advantages of precast concrete are:
- Saves time
- High strength
- Reduced wastage
- Aesthetic consistency
- High-quality assurance
Disadvantages Of Precast Concrete
However, while there are plenty of benefits to using precast concrete, the disadvantages must also be considered. The most pressing of these are the costs involved in transporting the completed elements from the factory to the construction site. Concrete is an extremely heavy material, and with potentially large quantities needing to be transported potentially long distances, the added costs will quickly mount. This is not much of an issue in Bahrain, as the country is small and petrol isn’t as expensive as it is in other countries, but it is still important to consider the costs involved to ensure it’s the right choice for your project.
A second challenge is the level of investment and effort involved in moving and placing the completed elements on site. Handling precast products is a difficult process which will often require portable or tower cranes, depending on the size of the project. This adds extra costs to your development, as well as extra training for handling this type of process. It is also difficult to modify precast elements once they are made, which will limit your ability to change design elements within the construction.
In summary, the disadvantages of precast concrete are:
- Modification after erection
Al Manaratain Precast Concrete
Al Manaratain offers two precast products; ‘Precast Slabs’ and ‘Pre-stressed Concrete T Beam Block Floors’. Though the slabs come with a standard width of 1200mm, these concrete products are available in a range of shapes, sizes and thicknesses, making them suitable for almost any building project. Needless to say, the pre-cast production and erection procedures used by Al Manaratain comply with British standards and conform to ministry specifications.