D-Beam® Technology

Steel & Precast.
Reimagined.

One trade. No formwork. No shoring. No above-grade concrete pours. Weather off the critical path - by design.

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Girder-Slab® grouting detail — hollow-core plank locked into D-Beam® channel with structural grout
D-Beam® and hollow-core plank cross-section showing composite floor assembly
D-Beam® structural system infographic showing assembly sequence and component names
D-Beam® Fabrication Illustration
D-Beam® girder fabrication — flat bar welded to wide-flange steel section
D-Beam® girder fabrication — completed assembly with clip angle beam connections
D-Beam® girder side view showing flat bar channel where hollow-core plank bears
D-Beam® girder cross-section without flat bar — Girder-Slab® structural assembly
Completed D-Beam® girders at steel fabrication shop ready for delivery
How the D-Beam® Works

The beam sits inside the slab, not below it.

The proprietary D-Beam® girder — an open-web dissymmetric steel beam — is designed to sit within the plane of the precast hollow core slab. This eliminates the beam-below-slab depth that defines conventional steel construction.

  • ✓18–24″ of floor-to-floor height saved per level
  • ✓No formwork, no shoring — slabs set directly on D-Beam® bottom flange
  • ✓No above-grade concrete pours — grout placed through web openings
  • ✓Single trade (ironworkers) — eliminates multi-trade sequencing conflicts
  • ✓Upper-floor plank set before lower-floor grouting completes
Assembly Sequence

One trade.
Six steps.
No concrete.

The complete assembly sequence performed by a single crew of ironworkers — no specialty trades, no wet concrete above grade, no weather-dependent waiting.

01
D-Beam® Erection
D-Beam® girders erected as part of the standard structural steel package — no separate mobilization required.
02
Hollow Core Slab Setting
Precast hollow core slabs set directly on the D-Beam® bottom flange. No formwork. No shoring. No concrete crew on site.
03
Upper-Floor Steel Proceeds
Upper-floor plank can be installed before lower-floor grouting is complete — breaking the sequential dependency.
04
Monolithic Grouting
Grout placed monolithically through D-Beam® web openings in a single operation. No above-grade concrete pour.
05
Composite Slab Complete
Composite slab complete after grouting. No curing wait required before upper-floor steel erection continues.
06
MEP Trades Follow Floor-by-Floor
Faster access for mechanical, electrical, and plumbing trades — no waiting on a complete structural pour.
Technical Specifications

Design standards &
structural performance.

Specification Detail
Design Approaches ASD (AISC 9th Edition) and LRFD (AISC 14th Edition)
Building Height No height limit — can be built as high as any other structural steel building
Lateral System Integrates with any standard lateral load-resisting system (braced frames, moment frames, concrete shear walls)
Fabrication D-Beam® fabricated by the project's local steel fabricator via standard competitive bid — no sole-source supplier
Precast Supply Hollow core slabs from builder's existing precast supplier — no sole-source requirement
Testing Villanova University and Auburn University — load-tested above code-required residential live loads
Fire Rating UL Floor-Ceiling Assembly K912, certified under ANSI/UL 263 (US) and CAN/ULC-S101 (Canada)
Restrained Assembly 2-hour and 3-hour ratings available; unrestrained 2-hour
Acoustic (STC) 56 bare plank; 59 with 2″ structural topping — both exceed IBC 50 minimum
Markets Served United States, Canada, India
Completed Buildings 400+ across residential, hospitality, student housing, senior living, and mixed-use
Acoustic Performance

Above code on STC.
IIC depends on floor finish.

The 8″ hollow core plank tests at STC 56 alone and STC 59 with a 2″ structural topping — both exceed the IBC 50 minimum for multifamily residential.

Impact isolation (IIC) is the same story it is for every concrete floor system: bare plank alone doesn't meet code — floor finish does. Carpet with pad reaches IIC 73+. Vinyl tile with sound-deadening underlayment reaches IIC 48–55. Standard residential assemblies clear the IBC 50 minimum comfortably.

All values below are from tested assemblies on Girder-Slab® precast hollow core plank.
IBC Minimum — Multifamily Residential
Required by code for party-wall and floor-ceiling assemblies
50
50
 
Tested Assembly
STC
IIC
vs. Code
8" hollow core plank — bare structural base
The structural assembly alone, before any floor finish
56
28
STC above
IIC below
8" hollow core + 2" normal-weight topping
Structural topping without floor covering
59
31
STC above
IIC below
8" plank + vinyl tile on 1/8" foam underlayment
Common specification for multifamily rental units
50
58
STC above
IIC above
8" plank + vinyl tile on sound-deadening board underlayment
Upgrade spec for condominium and hotel
54
51
STC above
IIC above
8" plank + 1½" topping + carpet & pad
Premium residential / hospitality specification
57
76
STC above
IIC above
8" plank + wood flooring on sound-deadening underlayment + suspended acoustical ceiling
High-end hotel / senior living specification
59
61
STC above
IIC above
Values from tested assemblies. A complete data set including 6" and 10" plank, gypsum concrete, wool carpet, and assemblies with suspended ceilings is available in the Acoustic Performance Data Sheet on the For Engineers page.
STC - Sound Transmission

Measures airborne sound isolation (voices, TV, music). Code-minimum STC 50 means a loud conversation in the unit above is audible but not intelligible. The Girder-Slab® assembly alone exceeds this baseline; floor coverings typically raise it further.

IIC - Impact Isolation

Measures impact sound (footsteps, dropped objects). Code-minimum IIC 50 is driven almost entirely by floor finish — this is true for every concrete floor system, not just Girder-Slab®. Standard residential finishes (carpet, vinyl with underlayment) clear the minimum comfortably.

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