Post on 18-Jan-2022
Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 1
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Scott M. Tarr, P.E. FACI
STarr@NorthSTarrConcrete.com
Guidance to Concrete Solutions
NORTH S TARRCONCRETE CONSULTING, P.C.
Concrete Slab on GroundDesign and Details
Concrete Slab on GroundDesign and Details
October 13, 2020October 13, 2020
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab Design
and Detailing
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
The slab every owner expects to see …
“Lab‐Crete”
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 2
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The slab they all too often see …
“Real‐Crete”
Guidance to Concrete Solutions
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Which often leads to making new friends along the way …
“Legal‐Crete”
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Making it all so much fun …
E
“Dis‐Crete”
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 3
Guidance to Concrete Solutions
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American Concrete Institute(ACI 360) Definition
Slab Design ‐ The decision‐making process of planning, sizing, detailing, and developing specifications preceding construction of slabs on ground.
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Designer Responsibility: Develop Clear Project Specs…
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Contractor Responsibility: Follow Project Specifications…
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 4
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Responsibilityof theSpecifier
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Resourcefor theSpecifier
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Slab DesignBending
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 5
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Load‐Carrying Capacity
• Determining Factors
Slab Thickness
Concrete Strength
Subgrade Modulus (k)
Assuming Load‐Transferis Achieved at Joints
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PCA Design Method
Concrete Slab Thickness
Typical Loading Conditions:
• Axle Loads – Lift Trucks• Post Loads – Rack Storage• Distributed Loads – Pallets, Boxes, Rolls
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Axle Load Design
In general, 80 to 85% of total loaded vehicle weight on front axle.Critical Design Axle Load
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 6
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Information Needed forAxle‐Load Design
• From materials, site, and designer‐ Concrete compressive strength
‐ Subgrade modulus
‐ Safety Factor (SF)
‐ Joint conditions – Joint Factor (JF)
• From lift truck specifications‐ Lift truck capacity
‐ Vehicle weight (total axle load)
‐ Wheel configuration and spacing
‐ Tire pressure
‐ Wheel contact area
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“I will only transport one palletat a time.
I promise…”
Why?
Design for Maximum Capacity
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NORTH S ETARRCONCRETE CONSULTING, P.C.
“I will only transport one palletat a time.
I promise…”
Why?
Design for Maximum Capacity
“Just OnePallet!”
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 7
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
“I will only transport one palletat a time.
I promise…”
Why?
Design for Maximum Capacity
“Just OnePallet!”
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Concrete Working Stress
WS = MR
SF x JF
where,WS = Working stressMR = Modulus of rupture (flexural strength)SF = Safety factorJF = Joint factor
Maximum Allowable Bending
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Concrete Working Stress
MR = 9 f’c
SF = 2.0 to 2.2 for unlimited load repetitions (>1.0)
JF = 1.0 to 1.61.0 – Load transfer provided at joints1.6 – Load transfer not reliableRange between at discretion of designer
based on concrete shrinkage potential andconfidence in dowel function
Concrete Flexural Fatigue Equations
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 8
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• Original PCA Charts developed for interior loading by pneumatic tired wheels
Joint Factor
• Stresses due to edge loading are higher - up to 60% higher
• Edge loading occurs at joints that do not have complete load transfer– Smooth dowel bars or dowel plates– Aggregate interlock decreases when joint opens
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Joint Factor
Concrete Shrinkage
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Engineering Judgement
• Joint Factor (JF)
• Safety Factor (SF)
• Applied Load Considerations
– Effective Contact Area
– Back‐to‐Back Post Legs
– Aisle Width v. Load Width
Complete Set of Design AssumptionsMust Be Considered!
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 9
Guidance to Concrete Solutions
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Too Safe?
Guidance to Concrete Solutions
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PCA Axle Load Design Charts
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
PCA Post Load Design Charts
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 10
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Responsibilityof theContractor
Perform ConstructionPer Specifications
And PerIndustry Standards
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Jointing
• Joint Types- Construction
- Isolation
- Contraction/Control
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Construction Joints
• Designate Pour Limits- Single Days Placement
• Butt-Type (Formed)- Keyways Not Recommended
• Must be Doweled- Load Transfer
- Prevent Differential Movement
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 11
Guidance to Concrete Solutions
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Guidance to Concrete Solutions
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Keyway Joints
Form Includes Keyway Notch
“Female” Side of Joint Cast
“Male” Side of Joint Cast
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Keyway Joints
Form Includes Keyway Notch
“Female” Side of Joint Cast
“Male” Side of Joint CastConcrete Shrinks and Joint WidensLoad Transfer is LostUnsupported “Female” Side Cracks
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 12
Guidance to Concrete Solutions
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Keyway Joints
Form Includes Keyway Notch
“Female” Side of Joint Cast
“Male” Side of Joint CastConcrete Shrinks and Joint WidensLoad Transfer is LostUnsupported “Female” Side Cracks
Guidance to Concrete Solutions
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Keyway Joints
Why do Keyways work for Pavement CenterlineJoints?
Because they Include Tiebars that Keep the Jointfrom Widening.
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Construction Joints
Edge Form – Bevel Top and Recess Stakes
Smooth Dowel – Bar or Plate
Cast Slab – Finish Over Edge Form
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 13
Guidance to Concrete Solutions
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Construction Joints
Edge Form – Bevel Top and Recess Stakes
Smooth Dowel – Bar or Plate
Cast Slab – Finish Over Edge Form
Remove Edge FormCast Adjacent Slab
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Isolation Joints
• Isolate Floor Slab- Perimeter Walls- Dock Levelers- Slab Penetrations
- Interior Columns, Drains, Plumbing, Electrical
• Joint Material- Compressible- Full-Depth
Guidance to Concrete Solutions
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 14
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Contraction Joints
• Control Random Cracking Due To Restraint to Concrete Shrinkage
• Installed at Proper:- Spacing
- Depth
- Timing
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 15
Guidance to Concrete Solutions
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Contraction Joints
Joint ‐ A crack placed where we want it to be.
Crack ‐ A joint placed where the concrete wants it to be.
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Joints are Generally Preferred
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Contraction Joint Spacing
• American Concrete Institute (ACI)- 36 Times Slab Thickness
6-in.-thick slab = 18 ft joint spacing
• Portland Cement Association (PCA)- Joint Spacing (ft) = 2 to 2.5 Thickness (in.)
6-in.-thick slab = 12 to 15 ft joint spacing
Maximum 30 Times Slab Thickness
15 ft (4.5 m) Maximum ‐ Pavements
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 16
Guidance to Concrete Solutions
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Contraction Joint Spacing
ACI360R
Random Crack Control Only!
Guidance to Concrete Solutions
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Contraction Joint Depth
• Create a Weakened Plane to determine Crack Location- How Deep?
- ¼ Slab Thickness6-in.-thick slab = 1½-in.-deep joint
• Grooving/Tooling or Sawcutting- Beware of Crack Promoting Insert (Vertical?)
Deep Enough to Cause Crack
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
The Boss said cut deeper this time
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 17
Guidance to Concrete Solutions
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Contraction Joint Timing
• Before Tensile Stress Exceeds Developed Tensile Strength (Crack)- Restraint to Volumetric Decrease
Friction, Penetrations
• Just After Peak Heat of Hydration (Cooling)- Drying Shrinkage & Temperature Contraction
- Generally 8 to 12 Hours After Placement
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NORTH S ETARRCONCRETE CONSULTING, P.C.
Joint Reinforcement
Transfer load from one panel to the next
- Aggregate Interlock
- Mechanical DevicesDowel BarsPlate Dowels
- Transferred Steel Reinforcement
• Load Transfer
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Aggregate Interlock
Sawcut Joint Activation
Minimal OpeningRequired
< 0.035 in.
Minimize ConcreteShrinkage andJoint Spacing
Be Aware of HowCracks Form in Slabs – “v” Shape
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 18
Guidance to Concrete Solutions
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Aggregate Interlock
Sawcut Joint Activation
Minimal OpeningRequired
< 0.035 in.
Minimize ConcreteShrinkage andJoint Spacing
Be Aware of HowCracks Form in Slabs – “v” Shape
Slab Surface
Widening>0.035 in.!!!
SlabBottom
Widening<0.001 in.!!!
Need to Measure Load‐Transfer to Determine Aggregate Interlock Effectiveness
0.050 in. 0.001 in.
“Effective” Widening = 0.025 in.?
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Mechanical Load Transfer
Devices Installed in Joint to Transfer Applied Load From One Slab Panel to the Adjacent Slab Panel.
Guidance to Concrete Solutions
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Align Dowels!
Mechanical Devices
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
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Guidance to Concrete Solutions
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Mechanical Devices
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Mechanical Devices
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Mechanical Devices
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
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Mechanical Devices
Must ConsolidateAround Dowels!
Guidance to Concrete Solutions
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Movement at Sawcut Joints
Sawcut Control Joint
Sawcut Control Joint
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Avoid
Joints!
“ “
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 21
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As the Discontinued Joint Widens,Differential Movement can CreateExcessive Tensile Stress Through“T” Joint Intersections Resulting inSympathetic Cracking
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Reinforcement Transferred Through Joints
• Welded Wire Fabric (WWF)
‐ Mesh ‐ Rolls or Sheets
• Reinforcing Bars
‐ Mats
• Post‐Tensioning
• Shrinkage-Compensating
Guidance to Concrete Solutions
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
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Cracks in Concrete Due toRestrained Shrinkage
Non‐reinforced
Reinforced
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 23
Guidance to Concrete Solutions
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Transfer Steel Through Joints
• ACI 360
‐ <0.1% Steel per Area of Concrete Cross‐Section‐ Enhanced Aggregate‐Interlock
‐ Cracking occurs beneath sawcuts only
‐ Joint Spacing per ACI 360R Figure 6.6
‐ >0.5% Steel per Area of Concrete Cross‐Section‐ Conventionally Reinforced Slab
‐ Visible tight cracks expected at 3‐5 ft spacing
‐ No sawcut joints necessary – no “control”
‐ 0.1‐0.5% Steel per Area of Concrete Cross‐Section‐ “Legalcrete”
‐ Visible random cracks that require filling
Guidance to Concrete Solutions
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Transfer Steel Through Joints
Guidance to Concrete Solutions
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Movement at Sawcut Joints
Sawcut Control Joint
Sawcut Control Joint
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 24
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Sawcut Control Joint
Sawcut Control Joint
Transfer Steel Through Joints
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Sawcut Control Joint
Sawcut Control Joint
Transfer Steel Through Joints
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Sawcut Control Joint
Sawcut Control Joint
Transfer Steel Through Joints
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 25
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Post-Tensioned Slabs
Tensioned tendons put slab into permanent compression.Therefore, no tensile stress and associated cracking.
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Post-Tensioned Slabs
Guidance to Concrete Solutions
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Shrinkage-Compensating Slabs
Expansive cement or an expansive admixture causesconcrete to expand (type K cement).
Steel reinforcement is tensioned and restrains expansion.
Concrete is put into compression – no cracking.
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
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Guidance to Concrete Solutions
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Extended-Joint Slab Systems• Design Extends Joint Spacing Beyond that Recommended by ACI 360.
– Presumably Assumes No/Minimal Out‐of‐Joint Random Cracking or Achieves Serviceable Cracking.• Owner Should be Informed of Expectation
– Must Accomplish One or More of the Following:• Reduce Concrete Shrinkage Potential to Negligible
• Reduce Restraint
• Keep Random Cracks Tight and Closely‐Spaced
– Design for Joint Widening (1/4 the Joints Results in 4 Times the Widening Per Joint)
– Slab Systems That Require Sawcut Contraction JointsShrink and Curl.
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Fiber Reinforcement
• Microsynthetic (0.1% or Less)
‐ Monofilament
‐ Fibrillated
• Macrosynthetic
‐ 0.25 to 1%
• Steel (0.25 to 0.5%)
‐ Smooth
‐ Deformed
Guidance to Concrete Solutions
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Concrete Slab on Ground Design and DetailsMinnesota Concrete Council
October 13, 2020
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Guidance to Concrete Solutions
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Time for a break …….
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Biggest Problems With Slabs
“Joints & Cracks”
Biggest Problems With Joints & Cracks
“Maintenance”
Biggest Factor Causing Problems
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Concrete Mix Design andPlacement Conditions
• High Compressive Strength• Low Water/Cement Ratio• Low Slump
• Required Strength and Durability
• Low Shrinkage Potential - ASTM C 157 and ACI 209R
• Good Workability/Finishability
Not forSlabs!
Guidance to Concrete Solutions
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Concrete Mix Design andPlacement Conditions
• High Compressive Strength• Low Water/Cement Ratio• Low Slump
• Required Strength and Durability
• Low Shrinkage Potential - ASTM C 157 and ACI 209R
• Good Workability/Finishability
Not forSlabs!
Guidance to Concrete Solutions
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Concrete Shrinkage/Contraction
• Temperature Contraction
• 3.2 to 7.5 millionths/ º F‐ 1/2 to 1 in. over 100 ft for 100ºF change
• Moisture Loss – Volumetric Shrinkage
• 0.020% to 0. 200%‐ 1/4 to 2‐1/2 in. in 100 ft
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Concrete Shrinkage
Exposed to Air
Not Exposed to Air
Curling/Warping
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Temperature CurlingOr
Moisture Warping
Differential Shrinkage
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Measured Moisture Gradient0
10
20
30
40
50
60
70
80
90
100
50 55 60 65 70 75 80 85 90 95 100
RH%
De
pth
, mm
concrete placed
(day zero)
9-days40-days70-days5 months
Slab with a vapor retarder immediately below
~10% RHGradient
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Guidance to Concrete Solutions
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Measured Moisture Gradient
Slab Relative Humidity Gradient
-2
0
2
4
6
8
10
0 20 40 60 80 100 120
Relative Humidity, Percent
Sla
b D
epth
, in
.
7-in.-thick slab
4-year old slab on draining base
9540
55% RHGradient
2
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Measured Moisture Gradient0
10
20
30
40
50
60
70
80
90
100
50 55 60 65 70 75 80 85 90 95 100
RH%
De
pth
, mm
concrete placed
(day zero)
9-days40-days70-days5 months
Slab with a vapor retarder immediately below
6 months
Guidance to Concrete Solutions
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Floor Covering FailureDue to Warping
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Curling/Warping Distress
Mid-Panel Crack as Warped Edges are Loaded
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Curling/Warping Distress
Actual Deformation Due to Slab WeightSlab Edges/Corners Crack Under Load
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Corner Breaks
• Unsupported Corners
(Curling/Warping)
• Crane Outriggers
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Corner Breaks
• Unsupported Corners
(Curling/Warping)
• Crane Outriggers
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Problems with Slab Warping
• Decreased Load-Carrying Capacity Resulting in Long-Term Slab Cracking- Mid-Panel Cracks
- Corner Breaks
• Slab Rocking – Joint Stability
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Joint Stability
Rocking as Warped Slab Panels are Trafficked
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Joint Stability
Rocking as Warped Slab Panels are Trafficked
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Joint Stability
<0.010 in.
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Problems with Slab Warping
• Decreased Load-Carrying Capacity Resulting in Long-Term Slab Cracking- Mid-Panel Cracks
- Corner Breaks
• Slab Rocking – Joint Stability
• Joint Spalling (Joint Filler Breakdown)
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Problems with Slab Warping
• Decreased Load-Carrying Capacity Resulting in Long-Term Slab Cracking- Mid-Panel Cracks
- Corner Breaks
• Slab Rocking – Joint Stability
• Joint Spalling (Joint Filler Breakdown)
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Joint Spalling
• Stable Joint
• Joint Filler Material
• Wheel Type/Traffic
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Exterior Pavement Joints
Install Foam Backer Rod
Install Flexible Joint Sealant
120 psi
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Interior Slab Joints
Pneumatic Tires
Solid RubberPolyurethane
Hard Wheels
700 – 800 psi
>1000 psi
100 – 200 psi
300 – 500 psi
Steel Wheels
>2500 psi
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
“Minimizing” Shrinkage andSlab Warping
• Use Quality Aggregate
• Minimize Paste Quantity- Increase Aggregate Size
- Optimize Aggregate Gradation
- Minimize Cement Content
• Maximize Paste Quality- Reasonable Water/Cement Ratio
- Just Enough Water for Workable Slump
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
8 – 18 Gradation?
In general, 5 – 22 percentretained provides workable mix
Blend aggregates to minimizealternating high and lowretainage on successive sieves.
Haystack Curve
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
8 – 18 Gradation?
In general, 5 – 22 percentretained provides workable mix
Blend aggregates to minimizealternating high and lowretainage on successive sieves.
Haystack Curve
Cook D, Ghaeezadah A, Ley T. Investigation of Optimized Graded Concrete for Oklahoma‐ Phase 1. FHWA‐OK‐13‐12. Oklahoma City, OK: Oklahoma Department of Transportation; 2013.
Tarantula Curve
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Workability Factor
Percent combined aggregatepassing #8 sieve
Coarseness Factor
Percent plus #8retained on 3/8 in. sieve
Blistering, Spalling, ScalingZone I
Zone IIOptimal Mix
Zone IIIOptimal Mix for max.aggregate <1/2 in.
Zone IVHigh Shrinkage
Zone V
Too coarse – non‐plastic
Coarseness Factor
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Minimizing Water (Paste)
• Use Good Quality Well‐Graded Aggregate
• Maximize Coarse Aggregate Topsize to Decrease Total Water in Mix
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Minimizing Water (Paste)
• Use Good Quality Well‐Graded Aggregate
• Maximize Coarse Aggregate Topsize to Decrease Total Water in Mix
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Maximum Coarse Aggregate Size
Slab Thickness, t:
t Dmax
For pumped concrete:
Dmax 1/3 diameter of hose or
1½ in.
whichever is smaller
Dmax T/3
Dmax ¾S
S
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Sieve Analysis ASTM C 136
Well-GradedVs.Gap-Graded
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Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 39
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Minimizing Paste Quantity
Balance Between:
and
Workability/Finishability
Low Shrinkage
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Minimizing Paste Quantity
Balance Between:
and
Workability/Finishability
Low Shrinkage
Aggregate Shadowing
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Expected Shrinkage
• ACI 360
– Low Shrinkage ‐ <0.052%
– “Typical” Shrinkage – 0.052 to 0.078%
– High Shrinkage ‐ >0.078%
• PCA 400 to 800 millionths
• CSA
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Pay Attention to the Details
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Dock Levelers
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Dock Levelers
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab Penetrations
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Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 42
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Floor Drain and Cleanout
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Re‐Entrant Corners and Discontinuous Joints
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Lateral Tie to Slab for Walls
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab on Ground Design and Details Conclusions
• Design and build for serviceability in accordance with owners expectations
• Anticipate the drying shrinkage potential for local materials when determining joint reinforcement
Aggregate Interlock
Dowels or Light Reinforcement
Heavy Reinforcement
Post‐Tensioned or Shrinkage‐Compensated
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab on Ground Design and Details Conclusions
• Design and build for serviceability in accordance with owners expectations
• Anticipate the drying shrinkage potential for local materials when determining joint reinforcement
• Predict the impact of each design and construction feature and advise the owner
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab Design and Construction Conclusions
• Design and build for serviceability in accordance with owners expectations
• Anticipate the drying shrinkage potential for local materials when determining joint reinforcement
• Predict the impact of each design and construction feature and advise the owner
• Always “design” an industrial floor slab. Don’t simply “specify” slabs
• And remember…
Aggregate Interlock
Dowels or Light Reinforcement
Heavy Reinforcement
Post‐Tensioned or Shrinkage‐Compensated
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Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab Design and Construction Conclusions
• Design and build for serviceability in accordance with owners expectations
• Anticipate the drying shrinkage potential for local materials when determining joint reinforcement
• Predict the impact of each design and construction feature and advise the owner
• Always “design” an industrial floor slab. Don’t simply “specify” slabs
• And remember…
Aggregate Interlock
Dowels or Light Reinforcement
Heavy Reinforcement
Post‐Tensioned or Shrinkage‐Compensated
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab on Ground Design and Details Conclusions
• Design and build for serviceability in accordance with owners expectations
• Anticipate the drying shrinkage potential for local materials when determining joint reinforcement
• Predict the impact of each design and construction feature and advise the owner
• Always “design” an industrial floor slab. Don’t simply “specify” slabs
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab Design and Construction Conclusions
• Design and build for serviceability in accordance with owners expectations
• Anticipate the drying shrinkage potential for local materials when determining joint reinforcement
• Predict the impact of each design and construction feature and advise the owner
• Always “design” an industrial floor slab. Don’t simply “specify” slabs
• And remember…
Aggregate Interlock
Dowels or Light Reinforcement
Heavy Reinforcement
Post‐Tensioned or Shrinkage‐Compensated
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Scott M. Tarr, PE FACISTarr@NorthSTarrConcrete.com 45
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Slab on Ground Design and Details Conclusions
• Design and build for serviceability in accordance with owners expectations
• Anticipate the drying shrinkage potential for local materials when determining joint reinforcement
• Predict the impact of each design and construction feature and advise the owner
• Always “design” an industrial floor slab. Don’t simply “specify” slabs
• And remember…
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Remain Calm!
Guidance to Concrete Solutions
NORTH S ETARRCONCRETE CONSULTING, P.C.
Thank You!
Scott M. Tarr, P.E. FACISTarr@NorthSTarrConcrete.com
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