slab_dlg.dcl — Slab Panel Configuration

File: slab_dlg.dcl
Version: v3.60
Category: Dialog Definitions
Size: 7.8 KB (235 lines)

Note

Horizontal Panel Type

Configure slab/deck panels (horizontal flat panels for floors, roofs, parking decks). Comprehensive settings for dimensions, edge details, openings, and reinforcement.

Functional Purpose

Slab Panel Design - Configures horizontal precast panels including dimensions, edge conditions, openings, supports, and reinforcement for floor/roof/deck applications.

Key Functions:

  1. Sets slab dimensions (length, width, thickness)

  2. Defines edge details (4 edges: square, beveled, tongue/groove, etc.)

  3. Configures openings (MEP penetrations, access hatches)

  4. Specifies support conditions (simple, continuous, cantilever)

  5. Determines reinforcement (mesh, bars, cover requirements)

  6. Controls surface finish (top and bottom surfaces)

User Need

Slab panels for:

  • Floor decks (office buildings, residential, industrial)

  • Roof decks (commercial, institutional buildings)

  • Parking garage floors (multi-level parking structures)

  • Mezzanine floors (warehouses, retail, industrial)

  • Bridge decks (pedestrian bridges, short-span vehicular)

  • Hollow-core alternatives (solid slabs vs hollow-core)

Typical Workflow

1. User in mp_dlg selects panel type: Slab
2. OR: User clicks Panel Type ? Slab
3. slab_dlg opens
4. User sets dimensions:
   • Length: 20'-0" (span direction)
   • Width: 8'-0" (typical module)
   • Thickness: 8" (based on span and load)
5. User configures edges:
   • Edge 1 (long, support): Square
   • Edge 2 (end, joint): Groove (for grout key)
   • Edge 3 (long, support): Square
   • Edge 4 (end, joint): Tongue (matches adjacent panel)
6. User adds opening:
   • Type: Rectangular duct opening
   • Size: 2'-0" × 2'-0"
   • Location: Center of panel
7. User sets supports:
   • Edge 1 & 3: Simple support on beams
   • Bearing width: 4" minimum
8. User clicks OK
9. Slab panel drawing generated (plan view)

Control Semantics

Primary Dimensions

Panel Size:

  • slw - Slab width (perpendicular to span):

    • Typical: 4’-0”, 8’-0”, 10’-0”, 12’-0”

    • Standard precast bed width: 8’-0”, 10’-0”

    • Maximum: Limited by transportation (~12’-14’)

  • sll - Slab length (span direction):

    • Based on span capacity

    • Typical: 15’-0” to 40’-0”

    • Maximum: ~60’-0” (camber considerations)

  • slt - Slab thickness:

    • Residential floor: 6”-8”

    • Commercial floor: 8”-10”

    • Parking deck: 8”-12”

    • Roof deck: 6”-8”

    • Based on: Span/20 to Span/30 ratio

Edge Details (4 edges)

Edge Types:

  • sle1 through sle4 - Edge detail dropdowns:

    Square Edge:

    • Flat, perpendicular cut

    • Simplest, most common

    • Use when: Bearing on beam/wall

    Beveled Edge:

    • 45° chamfer (typically 1/2” to 3/4”)

    • Reduces spalling at corners

    • Architectural appearance

    Tongue:

    • Projection for grouted joint

    • Typically 2”-3” projection

    • Matches groove in adjacent panel

    Groove:

    • Recess for grouted joint

    • Typically 2”-3” deep

    • Receives tongue from adjacent panel

    Recessed Edge:

    • For structural topping

    • Recess depth = topping thickness

    • Common in composite deck systems

    Pour Stop:

    • Upturned edge (2”-4” high)

    • Retains topping concrete

    • Creates composite action

Edge Assignment:

  • Edge 1: Long side (typically north/south)

  • Edge 2: Short side (end)

  • Edge 3: Long side (opposite Edge 1)

  • Edge 4: Short side (end, opposite Edge 2)

Openings

Opening Configuration (up to 16 typical):

  • slo1 through sloN - Opening enable toggles

Per Opening:

  • slot1 - Opening type:

    • Rectangular (most common)

    • Round (columns, pipes)

    • Custom shape

  • slow1 - Opening width

  • slol1 - Opening length (if rectangular)

  • slod1 - Opening diameter (if round)

  • slox1 - X position (from reference edge)

  • sloy1 - Y position (from reference edge)

Common Opening Types:

HVAC duct: 2'×2', 3'×2'
Plumbing chase: 1'×2', 2'×3'
Electrical conduit: 6"×12" to 12"×24"
Access hatch: 2'×2', 3'×3'
Column opening: 12"×12" to 24"×24"
Stair opening: 4'×10', 5'×12' (large!)

Support Conditions

Support Type per Edge:

  • sls1 through sls4 - Support type dropdowns:

    Simple Support:

    • Most common

    • Panel simply rests on support

    • Rotation allowed at support

    • Design for simple span

    Continuous Support:

    • Panel continues over support

    • Negative moment at support

    • Higher capacity

    • Requires top rebar continuity

    Cantilever:

    • Panel extends beyond support

    • Creates balcony, overhang

    • Requires careful design

    • Top rebar in cantilever zone

    Free Edge:

    • No support (interior edge)

    • Adjacent to opening or void

Bearing Width:

  • slb1 through slb4 - Bearing width per edge:

    • Minimum: 3” (ACI 318)

    • Typical: 4”-6”

    • Check bearing stress: P/(width × length)

Reinforcement

Reinforcement Pattern:

  • slr - Rebar layout:

    • Orthogonal mesh (most common)

    • One-way bars (spanning direction)

    • Two-way bars (both directions)

    • Custom pattern

Mesh/Bar Specification:

  • slm - Reinforcement type:

    • Welded wire mesh (WWM):

      • Light: 6×6 W1.4×W1.4

      • Standard: 6×6 W2.9×W2.9

      • Heavy: 6×6 W4.0×W4.0

    • Rebar:

      • #3 @ 12” o.c. (light)

      • #4 @ 12” o.c. (standard)

      • #5 @ 12” o.c. (heavy)

Cover Requirements:

  • slc - Concrete cover:

    • Bottom: 3/4” (suspended slab, interior)

    • Top: 3/4” (interior)

    • Exterior exposed: 2” (durability)

    • Form-faced: 3/4” minimum

Engineering Considerations

Thickness Determination

Span-to-Depth Ratios:

Simple Span:
L/h = 20 to 30 (typical)

Example:
20' span, L/h = 25
h = 20×12 / 25 = 9.6" ? Use 10" slab

30' span, L/h = 25
h = 30×12 / 25 = 14.4" ? Use 15" slab (thick!)

Continuous Span:
L/h = 28 to 35 (thinner than simple)

30' span, L/h = 30
h = 30×12 / 30 = 12" ? Use 12" slab

Load Capacity

Typical Floor Loads:

Residential: 40 PSF live + 20 PSF dead = 60 PSF total
Office: 50 PSF live + 25 PSF dead = 75 PSF
Retail: 100 PSF live + 30 PSF dead = 130 PSF
Parking: 40 PSF (H-20 wheel loads govern)

Capacity Check:
8" slab, 20' simple span, 5000 PSI concrete
Capacity: ~120 PSF (with typical reinforcement)
OK for residential, office
NOT OK for heavy retail

Edge Joint Types

Grouted Joint System:

Panel A: Tongue edge
Panel B: Groove edge
Grout joint: 1/2" to 1" wide

Installation:
1. Set Panel A (tongue edge facing Panel B location)
2. Set Panel B (groove edge receives tongue)
3. Grout joint fills gap
4. Creates shear key between panels
5. Load transfer across joint

Advantages:
? Structural continuity
? Level floor surface
? Load distribution

Used in: Parking garages, heavy loads

Dry Joint System:

Both panels: Square edges
Joint: Open or caulked

Installation:
1. Set Panel A
2. Set Panel B (small gap typical)
3. Caulk joint (if required)

Advantages:
? Faster installation
? No grout/curing wait time
? Simpler detailing

Used in: Roof decks, light loads
Limitation: No load transfer

Composite Topping System:

Panels: Recessed edges or rough top
Topping: 2"-3" concrete over panels

Installation:
1. Set panels with recessed edges
2. Place shear connectors (if required)
3. Pour topping concrete
4. Creates composite T-beam action

Advantages:
? Higher capacity (composite action)
? Level floor surface
? Runs utilities in topping
? Fire rating improvement

Used in: Multi-story buildings

User Example

Scenario: Office building floor deck, 25’×8’ panels

1. Panel Type: Slab
2. Dimensions:
   • Length: 25'-0" (span)
   • Width: 8'-0" (standard)
   • Thickness: 10" (L/30 = 25×12/30 = 10")
3. Edge Details:
   • Edge 1 (long, bearing): Square
   • Edge 2 (end, joint): Groove
   • Edge 3 (long, bearing): Square
   • Edge 4 (end, joint): Tongue
4. Openings:
   • Opening 1: 2'×2' HVAC duct
     - Location: 10' from end, 4' from side (centered)
   • Opening 2: 1'×1' plumbing chase
     - Location: Near end (bathroom location)
5. Supports:
   • Edge 1 & 3: Simple support on beams
   • Bearing width: 6"
6. Reinforcement:
   • Pattern: Two-way (floor slab)
   • Bottom: #4 @ 12" o.c. both directions
   • Top (at supports): #4 @ 18" o.c.
   • Cover: 3/4" both sides
7. Finish:
   • Top: Broom finish (for carpet/tile)
   • Bottom: Smooth form finish (exposed ceiling)
8. Result: 25'×8'×10" floor deck panel with grouted joints

Integration

Called By: mp_dlg ? Panel Type ? Slab OR slab button Drawing: slab.lsp generates plan view with edges, openings, reinforcement

Variables:

  • slab-width, slab-length, slab-thickness

  • slab-edge1 through slab-edge4 (edge types)

  • slab-openings (array of opening definitions)

  • slab-supports (support conditions)

  • slab-reinforcement (bar sizes, spacing)

Best Practices

Thickness Selection:

  • ? L/25 to L/30 for simple span (typical)

  • ? L/30 to L/35 for continuous span

  • ? Check deflection (L/360 live, L/240 total)

  • ? Don’t go too thin (cracking, deflection issues)

Edge Details:

  • ? Grouted joints for parking/heavy loads

  • ? Square edges for simple installations

  • ? Recessed edges for composite topping

  • ? Avoid tongue/groove mismatch with adjacent panels!

Openings:

  • ? Coordinate with MEP early (avoid changes)

  • ? Keep openings away from supports (2’ minimum)

  • ? Add reinforcement around large openings

  • ? Don’t locate openings in high-stress areas

Documentation Metadata

Enhancement Status: ? COMPREHENSIVE - ENHANCED [3/8]

End of Document