Deltabeam General Information
Why use Deltabeam?
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DELTABEAM® is a superior composite beam enabling slim-floors for multi-story buildings of any type. Its composite action between steel and concrete allows for creative structures with large open spaces. Underwriter laboratories (UL) fire tests have proven DELTABEAM® has excellent fire resistance without any additional protection for up to 4 hours. Its shallow design decreases a building’s floor-to-floor height while eliminating conflicts with HVAC and MEP systems.
What are the savings that can be made with Deltabeam?
Compared to standard construction methods, erection time and required labor is often greatly reduced.
With Deltabeam slim floor design, the number of stories can be maximized for a same building height. Therefore, the price per square foot is greatly reduced. Additionally, the slab spans can be increased, hence the number of column are reduced. Deltabeam's integrated fire resistance will often completely eliminate the need for fire proofing.
How many projects have used Deltabeam?
So far, over 12 000 projects around the world have used Deltabeam. Over 100 projects have been completed in North America since 2007.
For more information on Deltabeam projects please visit: http://references.peikkousa.com/
When was Deltabeam first used?
The first project that used Deltabeam was built in 1989 in Finland
Who is responsible for the design of Deltabeam?
All Deltabeam are designed by Peikko’s engineers and Peikko is fully responsible for the design of its beams. Stamped and sealed shop drawings are part of Peikko’s offering. The EOR will be responsible for other elements of the building such as vertical elements (columns and walls), lateral stability (bracing, shear walls, diaphragm etc.) and foundations.
Who is responsible for the fabrication of Deltabeam?
Peikko has established a network of designated fabricators to produce Deltabeam. Peikko is responsible for the quality assurance of all its products. The selected fabricators are AWS and AISC certified.
Who is responsible for the Deltabeam detailing?
Peikko provides its own shop drawing for every part manufactured. Here is a sample of a standard shop drawing produced by Peikko.
How does Deltabeam compare in cost with a steel wide flange or precast concrete beam?
Deltabeam costs approximately the same as a precast beam but is significantly shallower and lighter. Although the price for a steel wide flange beam may be lower than a Deltabeam per linear foot, Deltabeam will often lead to significant savings in the overall cost of the project.
For instance, lower floor to floor height will reduce cladding and HVAC Equipment costs. Also, reducing floor to floor height may allow for an additional floor for a given building height. Furthermore, Deltabeam's integrated fire resistance can eliminate the need for fireproofing.
In which type of project is Deltabeam the most cost effective?
Deltabeam can be utilized in any multi-story building, however it is most cost effective when utilized in a mixed-used application. For example, a residential building with indoor parking at the lower levels. Deltabeam is the most cost effective structural system when used in a rectangular grid layout. This way, hollow core slab spans can be maximized and will lead to a reduced number of columns and beams on a given floor layout.
Deltabeam design and features
How far can the Deltabeam span?
Deltabeam has the best depth to span ratio in the industry. The following table gives an overview of typical spans. Longer spans than those presented in the table shown below can be reached given that the beam can be deeper than the slab itself. Most of the time, Deltabeam's maximum span is limited to the hollow core slab span.
What is the optimal Deltabeam span and layout?
A rectangular grid layout is the optimal way to use Deltabeam, where Deltabeam spans vary between 20 and 26 feet with hollow-core slabs spanning between 27 and 42 feet.
How does Deltabeam achieve its fire resistance?
Deltabeam is UL listed for 1, 2, 3 & 4 hours without requiring any fireproofing material applied on the underside of the beam.
The rebars inside the profile ensure that the beam has sufficient capacity under fire.
The concrete inside the beam acts as a heat sink and slows significantly the rate at which the steel profile will rise in temperature.
Fire rebar shop installed inside the beam
Heat distribution inside the Deltabeam profile under fire condition
Has Deltabeam ever been used in high seismic area?
Yes, Deltabeam has been used in projects located in high seismic areas such as Honolulu(HI), Quebec City(QC) and Vancouver(BC).
Does Peikko provide design assistance?
Yes we do, from preliminary budget and layouts to construction site assistance, our engineering department will assist you through the entire design process.
Can Deltabeam support steel deck (metal deck)?
Yes, Deltabeam can be used with metal decks, hollow-core planks or wooden slabs.
Can Deltabeam be designed as an edge / spandrel beam?
Absolutely, Deltabeam can be designed as an interior beam as well as an edge beam.
Can Deltabeam be designed with a cantilever?
Yes, Deltabeam already been designed for cantilever up to 6ft.
Is Deltabeam produced with camber?
Yes, Deltabeams are manufactured with camber in order to accommodate the deflection limits specified by the building codes and to eliminate the need for shoring at mid span.
Should we design Deltabeam with multi-story or single-story columns?
Deltabeam can be designed with both multi-story and single-story columns. Single story columns allow usage of the negative bending moment of the beam. Therefore, overall beam weight and price may reduce by up to 20% .
However, since the entire load of the columns must be transferred through the beams, this type of construction is generally limited to 10 floors. Over 10 floors, continuous columns should be used.
Can Deltabeam be used with concrete columns or walls?
Yes, Deltabeam can be bearing either with a concrete column or wall. Peikko's PCs Corbel connection may be used to connect Deltabeam with vertical concrete elements.
Can Deltabeam be designed for point loads or non-uniform loading?
Absolutely, Peikko’s engineering department will gladly assist you with your specific loading requirements.
What types of plates are used to produce the Deltabeam?
All plates used to manufacture Deltabeam meet the requirement specified in ASTM A572.
Can holes be made in the Deltabeam for conduits?
Yes, however these holes must be coordinated with Peikko’s engineering department.
How are curves handled with hollow core slabs and Deltabeam?
Deltabeam can accommodate virtually any shape. Deltabeam edge beams can be produced with an integrated formwork that can be straight, skewed or curved.
How much height can I save with Deltabeam?
Total height gain depends on floors load, number of stories and depth of the beams and hollow core slabs. Height gain is typically 16" for 8" hollow core slab and up to 27" for a 12"mm deep hollow core slab.
How are cantilever balconies accommodated with Deltabeam?
There are two possibilities:
Cantilevering solid prestressed and precast slab:
Cantilevering the Deltabeam on the perimeter:
Connections
What are the possible connections with Deltabeam?
PCs Corbel welded to a steel column or casted in a concrete column can be used to connect Deltabeam to a column.
End plates can be added to a Deltabeam to weld it or bolt it to a steel column
Bearing surface such as top of a column or a wall can also be used as a connection
Deltabeam can even be connected to another Deltabeam by a side connection designed by Peikko.
Can Deltabeam to column connections be designed as pin connections?
Yes, Deltabeam when connected with a PCs Corbel is consider as a pin connections since only shear stress will be transferred by the corbel to the column.
Can Deltabeam be designed as a moment connection?
Yes, Deltabeam when connected by a welded of bolted end plate will act as a stiff connection which can transfer bending moment from the beam to the column.
Continuous Deltabeam will also provide moment connections between the column and the beam.
Shoring
Why do we need to shore Deltabeam?
Since Deltabeam is cambered, it doesn’t need to be shored for deflection. The reason why we need to shore the Deltabeam is to prevent torsion on the side of the beam where hollowcore is loaded first:
Where do we need to shore Deltabeam?
The shoring posts need to be placed at both ends of the beam under the web. Shoring must be placed on the side of the beam where the hollowcore slab is loaded first.
What is the capacity of the shoring posts that are required?
The posts must be able to support the full weight of the hollowcore slab bay. Typically the shoring post used must have a capacity of 20,000lbs.
Why do we not place any shoring posts in the middle of the span?
Since the beam is cambered, it is important to let the beam deflect during erection. If the Deltabeam is shored mid-span, cracking of the hollow-core could occur when removing the shoring posts.
Is there a way to completely avoid shoring?
Yes. Deltabeam has a very high torsion resistance due to its closed trapezoidal shape so given that the columns and the connections can accommodate this high torsion during the erection the shoring posts are not required.
How can I assure the structure is stable during erection? How is it braced?
Multiple systems can be used to temporarily brace the columns. We recommend using push and pull adjustable braces at least in the four corners of the building under construction as show below:
The braces can be secured in threaded holes at the top of the columns.
Grouting
When do I need to grout the erected floor?
Each floor must be grouted immediately after it is erected. A non-grouted floor provides no lateral stability and could collapse if multiple floors are erected without grouting.
In which order should I grout the components?
Composite columns should be grouted first, then the Deltabeam and finally the hollow-core keyways.
The hollowcore keyways can be grouted at the same time as the columns and beams when using a grouting bucket.
This method can also avoid requiring a concrete pump truck
How deep does the grout need to go at the end of the hollowcore slabs?
The grout will only go inside the hollowcore slabs a few inches. The hollowcore slabs are provided with plugs at the end of the cores to prevent grout from flowing inside.
How do I block the underside of the beam before grouting?
The formwork needed to block the openings under the slab is very minimal as shown in the pictures below:
Formwork prior to grouting
Once formwork is removed
