In the same way that the columns of a building are its backbone, beams are the skeleton. Horizontal structural members are used throughout to span gaps and to support loads, whether you are on a floor or on a roof or driving over a bridge. This is done with precision and efficiency that can only be achieved with precast concrete beams. Precast Concrete Beams are a critical component in the construction industry, and their applications as a construction material in all types of buildings, various project constructions and sizes are of necessity knowledge.
This guide addresses all of these aspects, explains them and discusses the wide variety of building applications in which precast beams offer tangible benefits.
What Is a Precast Concrete Beam?
Precast concrete beam is the horizontal structural member that is produced in a factory under controlled conditions, and then hoisted to the building site. Since manufacture, this process provides dimensional control, uniform quality of concrete for each specimen, and (for prestressed beams) compressive stress in the concrete prior to any service load.
Beams made of precast concrete are employed in building frames as load bearing horizontal elements. They are designed to provide structural support to buildings or bridges, and are available in different shapes and sizes, depending on the load they need to support.
Precast concrete beams are pre-made and robust beams that are used in construction. High tensile strength prestressed strands are used in the manufacturing process which enhance the resistance and load-bearing capacity of the cracks.
The main difference from a cast-in-place beam is simple: The factory does the hard work, before the beam ever gets to your location. That moves labour away from the construction site, shortens programmes and creates a structural element of quality, with measurable quality, that is significantly greater and more consistent than field-poured alternatives.
There Are Several Types of Precast Concrete Beams, Such As:
Knowing the fundamental types of beams can help with applications (after all, the shape of the beam dictates where and how it can best be applied).
Rectangular beams are so named because of their end shape. Most often these are used to span between clear spaces and are reinforced or prestressed. Inverted T-beams are typically employed in flooring systems such as beam and infill where they offer a ledger on which the precast floor units are placed. L-beams are L-shaped with a ledge profile that is used for supporting a precast flooring system over clear areas and are typically used to span clear spaces.
Most often in structural precast frames, rectangular beam, L-beam, inverted T-beam and I-beam are used. The car park building benefits from inverted T-beams because the ledge on either side of the web supports the end of hollow-core slabs or double-tee units with a shallow overall floor depth. In bridge construction, long spans of up to 40 metres are used, and I-beams and U-beams are used.
L-beams, also called angle beams, are made of reinforced steel and prestressed/post-tension steel strands that are capable of supporting heavy loads and resisting twisting and bending. The inverted T beam is a wide bottom horizontal portion called a flange and a tall up vertical portion that can carry heavy loads.
Gulf Precast, the largest precast producer in the UAE, has an extremely broad selection of beams of various types for use in low-rise and high-rise buildings, car parks, bridges and many other structures. They are intended to be used as composite sections, with connections considered as hinged, semi-rigid or rigid as per structural requirement, depending on the type of concrete topping or screed on top of the slab.
Building Frames: Beams at Work All the Time
Precast concrete beams are the most familiar and widely used precast application, the structural building frame. Each time a precast beam is used to connect two columns and to support a floor above it, it is working to its designed capacity.
Precast beams and columns can be employed if you have to make up building frames in a short amount of time. The beams support the floor while the columns support the beams.
The precast beam is at the heart of the precast building system, which is preferred by the UAE’s top precast manufacturers. They are used to carry loads from hollow core slabs or double tee units between the slabs, transfer to the precast columns at bearing points, and allow the whole floor system to be rapidly assembled, without any on-site forming or casting.
Precast beams offer a versatile solution that can be used in a variety of ways to meet the structural needs of any project. They provide a perfect solution for installing precast structural and architectural wall panels and installing hollow core floor slabs. Precast beams are ideally suited to underground parking buildings to maximize the use of the floor space, thereby allowing such structures to be built on a smaller lot.
The Application of Multi-Storey Car Parks is Proven and Specialist
If you ask any precast engineer what their most frequent use of inverted T and L beams is, the answer will be “parking structures.” These beam patterns are particularly suitable for a multi-storey car park construction project as the geometry of the beam patterns is ideal.
Precast concrete is often used for multi-storey car parks. The construction comprises the assembly of precast parking elements such as structural floors, girders, wall panels, stairs and slabs.
The hollow core slab is placed on the ledges along the sides of the web of the inverted T-beam to provide a flat soffit and maximum headroom for overhang of the vehicle. The overall shallow floor depth achieved through this design lets more parking surface in a particular building height, which is a real value engineering benefit in land constrained UAE markets.
Industrial Warehouses & Logistics Facilities
Precast beams for large span structures are the preferred option for industrial warehouses, distribution centres and logistics centres in UAE and across the Gulf.
With the expansion of e-commerce and manufacturing in the UAE’s Operation 300bn, demand for warehouses and industrial facilities that provide clear spaces with columns and beams is increasing which is where long span precast beams and columns are being seen.
Double T beams are used in structures which demand long spans and large spaces, like schools, warehouses, and parking garages. They are produced with rebar and prestressed or post-tensioned concrete, making them more durable, longer-lasting and carrying high loads.
In logistics warehouses, a single internal column will disrupt any racked layout, forklift movement and loading bay placement. Long-span precast beams solve that by spanning the roof loads over spans that would be impractical with conventional constructions using heavyweight steel.
Bridge Construction: The Long-Span Specialist
The precast concrete beams are the backbone of today’s bridge construction. They span extensively, can support the high dynamic loading experienced by bridges and they are very resistant to decay that occurs over many years of use, so they are the preferred material for bridge decks around the world.
Precast concrete can be utilized in bridge construction to produce a variety of components, such as precast deck slabs, precast girders, precast arches, precast beams and precast bridge caps. It can span any size of bridge, and engineers can create precast pieces that will match the natural or historic surroundings.
Precast bridge beams can span long distances, with a maximum span of up to 45 metres depending on the load. Some can be used on flyover bridges on motorways, pedestrian bridges, commercial developments and marine jetties. These can be varied in shape and size according to the specific project’s needs.
In the UAE, precast bridge beams have played a key role in the country’s motorway infrastructure, metro projects, as well as marine applications, where both structural performance and installation speed are of premium value.
Commercial and Office Buildings
Commercial buildings from office towers to retail centers, or mixed-use developments, require structural systems that provide open and adaptable floor plates. Precast concrete beams, coupled with hollow core slabs, provide just that.
Precast concrete beams and columns are structural elements that can be used to support vertical loads in buildings and other structures. They are commonly used in the construction of bridges, parking structures, and building frames to support heavy loads and provide long-lasting performance.
The multiple spans, quality control by the factory and quick erection on-site match up well with the timeframe requirements of the commercial developers in the UAE. The financial value of a structure built 3-4 weeks earlier than a cast in place structure is quite valuable, particularly in a market where rental income only starts once practical completion.
Railway and Infrastructure Projects
The precast beams are used to carry heavy loads in railway bridges and underpasses in the railway infrastructure. They are used in commercial and industrial buildings to improve the safety and stability of warehouses and industrial buildings. They are used in utility structures and sound barrier walls in specialised infrastructure projects and are less expensive than other materials.
Precast concrete components were extensively used during the construction of the UAE’s metro system, which was a massive undertaking and faced numerous challenges. The quality of the beams was established with control in the factory, which helped to achieve a high degree of uniformity and reliability over the lifespan of the public transport system. The high-quality consistency and reliability over decades of operation, required by a high-frequency public transport system, was achieved in part thanks to the controlled quality of the factory-made beams.
School Buildings, Hospitals and Institutional Buildings
The UAE’s most common building projects, such as schools, universities, hospitals, and government structures, have been using precast concrete beams, not just for their structural capabilities. Public service buildings which will serve for 50 years or longer are taken into account when making a procurement decision for fire resistance, acoustic performance and low life cycle maintenance.
Precast concrete building components are used in building structures such as parking garages, schools, bridges and warehouses. They are suitable for structures that require long-term durability and strength, such as those in harsh environments or those that are subject to heavy loads.
Additionally, precast beams in hospitals, schools and other occupied buildings have the added benefit of predictable and rapid erection sequences which minimise disruption to surrounding occupied areas. That’s a very big deal on a school campus extension, or on a hospital expansion.
Why UAE Construction Favours Precast Beams
The advantages of precast concrete beams that are relevant to any part of the world contribute to the benefits in the UAE construction environment.
Precast concrete is more resistant to cracking, corrosion, impact and environmental damage. Precast concrete is used for most of the infrastructure projects in UAE that include bridges, tunnels and drainage systems because of this increased durability. The precast construction methods such as concrete mixing, pouring and cutting, are very efficient with minimal waste and are consistent with Vision 2030 and Green Building Regulations in the UAE.
Concrete’s chloride resistance, and its cover over reinforcing materials, are important properties for the UAE’s coastal environment, which is characterized by salt-laden air, high humidity, temperature changes, and more. Not only is it a predictable process, but it’s also one that’s more likely to be done correctly than casting precast beams in summer heat, which may be 45 degrees on site.
Speed matters too. Beams used in precast concrete construction ease construction and enhance overall structural performance. They are quickly installed, which cuts down on the time required on site compared to traditional construction processes.
Precast beams provide both cost and liability savings as each day on-site and each month of delay result in a cost.
Final Thoughts on Precast Concrete Beams Used for in Construction
Precast concrete beams are incredibly versatile structural elements. They provide support and carrying capacity in multi-storey buildings, support parking decks, span rivers, motorways, frame industrial warehouses and hold up institutional buildings which are designed to last generations. The answer isn’t: “Will precast beams be used in my project or not?” It’s not a question of whether precast beams will be used or not. The question is, what type and configuration is most appropriate for your structural design — and what manufacturer in UAE is qualified to provide you with the engineering know-how needed to help answer that one correctly.
Where possible, Gulf Precast optimises slenderness and economy throughout the range of applications that precast beams offer by designing beams as a composite section with consideration of the concrete topping/screed of the slab above.
The way effective precast concrete construction is designed — as part of the system — instead of as an independent entity — is the reason it works so well.
