Span Length

General Notes: Max hollow core lengths are generally set using the span-to-depth ratio of 45:1 outlined in the PCI Manual for the Design of Hollow Core Slabs; engineer discretion needed for further lengths.

All values are in compliance with ACI 318-19, PCI MNL 126-15, PCI MNL 120-17

18′ 24′ 30′ 36′ 42′ 48′ 54′ Span Length 8" Composite 18′ - 40′ 8" Non-Composite 18′ - 44′ 10" Composite 18′ - 44′ 10" Non-Composite 18′ - 48′ 12" Composite 18′ - 46′ 12" Non-Composite 18′ - 50′

Hollowcore Load Table - Max Live Load (PSF)

Span (ft) 8" Composite 8" Non-Composite 12" Composite 12" Non-Composite
18 370 270 460 385
20 325 245 400 310
22 285 220 355 295
24 255 195 315 265
26 230 175 285 235
28 205 160 250 200
30 190 145 230 195
32 160 130 210 185
34 140 110 195 165
36 115 100 175 150
38 90 80 160 140
40 70 65 150 130
42 50 50 135 120
44 30 40 125 110
46 - 35 115 105
48 - 25 105 95
50 - - 95 90

Product Information

Hollow Core is produced in standard 4′-0″ wide planks that can be saw cut to fit the length and width requirements for the project. A topping slab can be used, both composite and non-composite, depending on the design requirements.

Standard Design Options

  • Suspended utility hanger assemblies
  • Hollowcore hangers for larger blockouts
  • Hollowcore ripping for narrow planks
  • 4′-0″ nominal Widths
Technical drawing of a 12-inch hollow drone core section showing a rectangular plate with four circular holes and mounting hardware. Technical drawing of a 12-inch hollowcore concrete section showing a cross-section with four evenly spaced circular cores and dimensioned measurements. Technical drawing of an 8-inch hollowcore slab showing eight circular voids with horizontal and vertical dimension lines and centerline markers. Foundation mat with seven columns spaced 6 feet apart on a 9-foot-wide uniform grid, illustrating acceptable column spacing for structural design. Crane hoists a large concrete girder using an orange spreader bar onto a flatbed truck, with a worker in safety gear nearby under a clear blue sky. Crane lifts a concrete beam at an active construction site with a building under construction and workers on site. Workers guide a crane lifting a large concrete girder at a construction site surrounded by trees. Yellow crane lifts a load near concrete foundations at a wooded construction site. Stacked precast hollowcore concrete slabs on a construction site, with red stenciled markings reading

3D Viewer

3D Viewer Tools

 

  • 3D Viewer Functions:
  • Move, Span, Zoom Assemblies
  • Isolate Single Components in View
  • Explode Assembly Single Components
  • Use Markup to Sketch Details
  • General Measurements for Concept
  • Print Views

Need More Info?

We Are Here to Help

 

Have a question, need a budget or detailed schedule?  Knife River sales team is ready to discuss precast solutions for your project.  Reach out to our staff below :

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Andy Roberts

Outside Sales, ID & MT

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509.904.8610
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Nikolaus Mixon

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541.257.7412
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Zak Perkerewicz

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(503) 545-3284

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