A prestressed concrete beam can do something that a normal beam cannot: resist the load before it is imposed. If done incorrectly, however, that advantage vanishes quickly, and that’s a problem. This guide explains exactly how to select the best prestressed concrete element manufacturer in the UAE so that your structure will be as strong as the technology can make it, and not simply the price tag.
The Manufacturer Decision Is Made Before the Product Decision
There are a lot of guides out there that tell about prestressed concrete theory and that’s it. The other half of the story is… Prestressing is a process with a strong engineering side, and the quality of the process that the manufacturer employs determines whether that engineering will result in a safe structure or an unwelcome liability.
The idea of prestressing is to deliberately put compressive stresses in a concrete member before applying service loads in order to counterbalance tensile stresses that may arise under service loads. That accuracy must be done right, on each and every single element. The manufacturer that does this routine casting is a wrong manufacturer to trust with your project.
Before You Buy Anything, Make Sure You Know Exactly What You Are Purchasing
It’s important to have an understanding of how the two main methods for creating prestressed elements are accomplished first so that you can compare manufacturers, as most manufacturers are focused on one or the other.
Pretensioning is set up in the factory. The steel strands are tensioned, then concrete is poured between the strands, and then the concrete is cured, and the tension is transferred to the member. The method is mainly used for precast prestressed members produced in permanent plants, where the pretensioning bed can be used for several production cycles.
The opposite process is true for post-tensioning. The strand is placed within ducts and tensioning is done after the concrete has cured, using hydraulic jacks against plates at the end of the members to impart the stress. This approach works well for larger, more complicated, or site-cast components, where a portable factory bed is not feasible.
Once you’ve determined the method required you’ll immediately have a smaller number of manufacturers from which to choose, as pre-tensioned precast units such as slabs can be produced efficiently in a factory with set up, while post-tensioning can be used to provide a tailored prestress for complex shapes onsite. If your job doesn’t need a manufacturer that only has one method, then it’s not the right one for you, but it might be the right one for your application.
What Exactly Does Prestressing Bring to the Economy?
The manufacturer should be able to tell you simply why prestressed elements are better suited to your project than a normal reinforced concrete structure. When they cannot, it’s worth taking note of.
The actual benefits are well known. The use of prestressed concrete means crack control, reduced construction costs, and thinner slabs, particularly in high-rise structures where each millimetre of slab thickness saved could mean an extra floor in a building at no extra cost. It further decreases the number of joints required in a structure, and fewer joints results in lower maintenance costs throughout the building’s design life, as joints are generally the most vulnerable location in a concrete structure.
Longer spans also count. Prestressing allows engineers to make longer span beams and slabs than what would otherwise be possible with only regular reinforced concrete; this will save on the cost of construction by reducing the number of supporting columns required. This is the advantage you can get for your project if you require open floor plans or wide column-free spans. Always ask your manufacturer to cite these gains, and not just “it’s stronger” as a slogan.
Verify Their Bonding and Transfer Details
That is where the real distinction between suppliers in terms of manufacturing quality becomes apparent. For pretensioned elements, the force of bond between the strand and the concrete is what creates the force in the element and this force is dependent on the control of the production process. The transfer length to achieve the complete development of the prestressing force through bond is typically between 50 and 100 strand diameters, depending on the surface condition of the strands and the strength of the concrete.
Inquire with your manufacturer about how they are meeting these transfer requirements every time with the surface conditioning of the strand and the strength of the concrete. Any manufacturer who can give a specific, repeatable response here knows the engineering. Asking someone to “just trust the process” isn’t a good sign of a load-bearing element.
Look at Span Capability, Not Just Product Category
One of the most prevalent prestressed elements used in construction projects in UAE is the prestressed hollowcore slab and the span capability is where manufacturers can really distinguish. Hard Precast Building Systems is one UAE precast large-scale producer, producing pre-stressed hollow core slabs with spans of up to 24 metres in its production plant in Dubai Investment Park. Hollowcore production equipment distributed across United Precast Holding locations in Bahrain, Dubai and Abu Dhabi can manufacture slabs between 150 mm and 500 mm thick, which is another region, in addition to the other two regions.
Hardprecast
Uphgroup
The numbers are important because they directly indicate whether a manufacturer’s stock product line will fit a project or whether the manufacturer will be going outside their comfort zone.
Check Their References and Experience
It probably says something that they’ve been steadily producing prestressed concrete for this many years without getting the “shark” treatment. Gulf Precast Concrete Company has been in operation in the UAE for more than four decades with five factories and six production lines that have a combined capacity of 1,500 cubic metres per day, including the production of prestressed concrete. Abu Dhabi Precast has been operating since 2001 manufacturing precast and pre-stressed concrete products and Concrete Technology LLC has been supplying the prestressed concrete market in the UAE since 1997.
Gulfprecast + 2
All this does not mean older is always better, but it does indicate that not all older is good. However, a manufacturer who has enjoyed many years of experience in the production of prestressed concrete has learned some of the lessons that other manufacturers are still learning.
Ask Questions About QA/QC and Engineering Support
Prestressed elements are not made to order like paving stones. They require engineering input, specific to your loading, span and site conditions. Manufacturers with real engineering experience introduce dedicated QA/QC, engineering design and project management teams to the table, rather than just a factory and a price list.
Before production begins, ask:
- Who will be looking at your project’s loading requirements?
- Does the manufacturer offer shop drawings specific to your structure?
A supplier who considers all orders the same has not necessarily developed something special for you.
Learn to Identify the Red Flags
There are a few red flags that surface every time with lower quality prestressed concrete suppliers. If you don’t hear a clear answer when they ask what they use for prestressing and why, if they don’t have a standard answer to you for your span, if they don’t tell you if they have a standard thickness range for their products, if their engineering or QA/QC team is not more than the production staff, and if they have no verifiable project history that is the scale you need, you’ll know they’re emptying the cup.
All of these should not be a reason to immediately reject any manufacturer. However, two or three at a time are an indicator that it’s time to back off and ask more challenging questions before committing.
Integrating All the Pieces
The key concrete checks that should be considered when selecting the right prestressed concrete element manufacturer in the UAE include checking if the project requires prestressed concrete elements to be pretensioned or post-tensioned, confirming the span and thickness range provided by the manufacturer aligns with the project’s specifications, verifying the manufacturer’s bonding and transfer process controls, and reviewing their previous projects of similar scale.
You’re taking the chance that a structural component that is supposed to resist tension won’t be subjected to tension until it’s installed, and that the manufacturer is able to keep it that way. If you get it right, your prestressed concrete will do exactly what the technology was meant to do: span longer, slabs thinner and a structure that quietly relies for decades.
