H-beams have been used in construction projects for over a century in the construction of high rise buildings (P1)
The Use of Steel H-beams in Construction
Recent years have witnessed a notable surge in construction projects across the country. In an effort to keep pace, developers are always on the lookout for better construction methods – especially to reduce build times and increase utilizable floor space (sqft area). A significant factor affecting both these objectives is the construction of columns.
Columns play a critical role in construction by providing the necessary support to a building. They are usually made of reinforced concrete, which consists of several steel rods with concrete poured in a mold around them. A popular alternative is Steel H-beams. These beams allow for better construction all-round by having a higher load bearing capacity. Furthermore as these beams are prefabricated, they offer many benefits to the construction process.
Using H-beams constructors can keep more area between each of the support columns (P2)
Increased Utilizable Floor Space
Steel-H beams have a higher load bearing capacity therefore fewer are needed per area when compared to reinforced concrete columns. Furthermore each column occupies less space than their reinforced concrete counterparts. This means that there will be fewer columns obstructing the floor space inside your building. Additionally each of these columns will take up less space, thus maximizing the usable floor area available to the future tenants of the building.
The formwork around the steel rods or H beams form a mold the concrete can be poured into (P3)
Reduced Construction Time
Construction is much faster with H-beams when compared to reinforced concrete columns. As a result of arriving to the site prefabricated, the erecting and welding of these columns for a 5000 square foot (sqft) floor can take as little as 5 days. Whereas constructing a floor with the same sqft area using reinforced concrete columns, which needs formwork, can take up to 27 days as the concrete mix needs time to set properly.
The scheduling of cement mixes can be a challenge with restrictions on the times heavy vehicles can enter the city (P4)
Reduced Logistical Challenges
Steel H-beams have a higher load bearing capacity and are lighter than reinforced concrete columns. Therefore it reduces the material weight that needs to be brought onto the site. Additionally, as many cities including Colombo have restrictions on the times heavy vehicles can enter, construction sites that use reinforced concrete columns are expected to schedule the transportation of large quantities of premixed cement to the site at night. This hassle can be avoided through the use of Steel H-beams, as they do not require concrete formwork.
Construction projects are highly labour intensive (P5)
Reduced Labour Costs
The use of Steel H-beams results in significantly reduced labour charges as they do not require formwork. As mentioned before when using reinforced concrete columns, the premixed concrete needs to be brought to the site at night. This means the formwork needs to be done at night, adding to Overtime (OT) labour costs. Furthermore as Steel H-beams have a higher load bearing capacity and come prefabricated, the amount of labour required for a project reduces. However as the skills and machinery needed to construct with Steel H-beams are different to those needed when constructing with reinforced concrete columns, make sure to select a contractor with the right experience and capabilities.
Alterations are easier with H-beams (P6)
Easy Alterations to the Design
Alterations to the construction design such as relocating columns can be done much more easily and with almost no material wastage when using Steel H-beams. Unlike when using reinforced concrete columns that have to be broken down, H-beams can be electro cut and welded in another location. This saves material and reduces the alteration time to only 1 day as opposed to 2 to 3 days!
In Sri Lanka Steel H beams are commonly used in conjunction with concrete molds (P7)
Current Use of Steel H-beams in Sri Lanka
Although Steel H-beams are utilized in larger construction projects in Sri Lanka, they are generally used together with concrete. While this method takes advantage of the increased load bearing capabilities of Steel H-beams, it does not utilize its time saving benefits.
There are two reasons concrete is used together with the steel beams in construction. The first is to increase the thermal bearing of the column, and the second is to satisfy the design requirements of the market. However, both of these can be resolved quite easily.
Better practices for a brighter tomorrow (P8)
Using concrete in conjunction with Steel H-beams can be avoided. To increase the thermal bearing capacity of the H-beam columns alternatives available in the market include intumescent paints, cementitious sprays and fireproof cladding. (1) These solutions can be used independently or in conjunction to ensure that the construction meets the highest fire safety standards.
Apart from the use of product alternatives it is also important to increase awareness regarding the benefits Steel H-beams can provide to clients, designers and architects. Increased awareness can benefit market competition, reduce material wastage and help developers save a significant amount of time and money on their construction projects.