How to choose the model of steel deck

In the last blog, we analyzed the classification of steel decks, which pointed out the direction for us when choosing the steel deck model. What is the basis for choosing steel deck models?

1. The thickness of the floor slab

Under normal circumstances, the thickness of the floor slab will be around 120mm, and we will recommend customers to choose high-rib steel decks. Such as: SD76-915, SD65-555, SD66-720, etc. If the floor thickness is less than 100mm, we will suggest customers to choose low-rib steel decks, such as: SD35-750, SD38-915, SD46-600, etc.

Some customers want to build a mezzanine, but due to space requirements, they hope that the thickness of the mezzanine floor should be as small as possible. The thickness of the floor is 100mm, even 80mm, 90mm, so we will recommend customers to choose low ribs, SD35-750, SD38-915, SD46-200-600. Because the code stipulates that the thickness of the concrete should be at least 50mm higher than the top of the rib in terms of structure.

2. Secondary beam span

As for the span of the secondary beam, the span of the secondary beam designed by the structural designer will mostly not exceed 3 meters, generally more than 2 meters. Usually we only ask the customer what the maximum span is. If the span is too large, and the area with a large span is a small area for the entire plane, we will advise the customer to add angle steel or temporary The support shall be dismantled after the concrete pouring is completed and the design strength reaches more than 75%. (Angle steel can be used as permanent support)

3. Load

According to the code, the stress calculation during construction is based on a uniform load of 1.5KN/m2 and a concentrated load of 2.2KN/m2. Of course, this needs to be provided by the customer, and there will be instructions in the general design drawings. Some projects have equipment floors or floors with relatively heavy loads. The slab thickness of these floors will be relatively thick, and the construction load and subsequent load will be relatively large. We will advise customers to choose steel decks with relatively large cross-sectional properties.

4. Requirements for fire resistance

According to codes, buildings must consider fire protection requirements. Steel from deck can only be used as a formwork, and then add stress reinforcement; while steel floor deck can be combined with concrete to form a composite floor. Then according to BS, choose the type of steel deck according to the fire resistance aging.

5. The area where the building is located or its surrounding

5. The area where the building is located or its surrounding environment, usage and other conditions

Finally, we will also consider the area where the building is located or the surrounding environment. For example, if the area where the building is located or the surrounding environment is relatively humid, then the corrosion intensity of the steel deck will be relatively high. In this case, we will advise customers to choose anti-corrosion Flat profile with good corrosion performance or increase the stress reinforcement at the bottom of the steel deck, and use it as reserve reinforcement.

Of course, we will comprehensively consider the above 5 situations and recommend the most suitable steel deck model to the customer.