Precast Wall Panel Design. By Edward Losch, PE, SE

Transcription

1 Precast Wall Panel Design By Edward Losch, PE, SE

2 What is a Precast Concrete Sandwich Wall Panel?

3 Typical Precast Concrete Sandwich Wall Panel

4 Long-Line Form

5 Wythe(s) Prestressed

6 Trucked & Erected (Non-loadbearing)

7 Load-Bearing Panels

8 Non-Composite Composite

9 How are Sandwich Wall Panels Manufactured?

10 Wet-Cast:

11 Shear Trusses Solid Zones Wet-Cast Composite Design

12 Non-Composite Wythe Connectors

13 Pin Connectors Inserted in Pre-Drilled Holes

14 Reveal Strips Glued to Steel Form

15 Form Liner Located in Panel Form

16 Panel with Form Liner Impression and Reveals

17 Cornice Cast Separately, Attached at Site

18 Sandblasting Panel - Side Lifters Required

19 Stained Finish

20 Corewall Panel with Random Rib Finish

21 Random Rib Finish

22 Dry-Cast: Spancrete Non-composite Wall Panel Section

23 8 ft. Wide Spancrete Panels

24 Spancrete 8 ft. Spandrel Panels:

25 Double-Tee Wall Panel Section

26 PEC Soundwall

27 PEC Soundwall form used for Scattered- Site housing in Chicago

28 Scattered-Site Housing

29 Scattered- Site Housing

30 Insulation Types: - Expanded Polystyrene, R=4 per inch - Extruded Polystyrene, R = 5 - Polyisocyanurate, R = 7 to 10 - Phenolic foam: can cause corrosion when wet!

31 Thermal Lag from Concrete Panel Mass

32 Thermal Lag from Mass of Concrete Panel

33 Manufacturing Tolerances Use PCI Mnl 116 (not 117): Manual for Quality Control for Plants and Production of Structural Precast Concrete Products

34 How are Sandwich Wall Panels Handled & Erected?

35 Lifter Locations for Stripping & Handling

36 Yard Storage

37 Yard Handling with Shuttle-Lift

38 Trucking Extra-Wide Panel on Slant Frame:

39 Panels arriving at the Job Site

40 Single-Line Lift

41 Two-Line Lift

42 Face Lifters in Form

43 Top Edge Lifters in Form

44 Bracing Guidelines: - Use ASCE 7-95 Design Loads - Reduce from 50 yr to 5 yr Re-occurrence - Use 1.5 Factor of Safety for Pipe Braces

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46 Brace to Deadmen :

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48 How are Sandwich Wall Panels Designed?

49 Sandwich Wall Panel with Dock Door Opening - Plan View

50 Sandwich Wall Panel with Dock Door Opening - Section

51 Stripping Forces, Shear and Moment Diagrams

52 Stripping Stresses with 1.4 Handling Factor

53 Erection Forces, Shear and Moment Diagrams - 2 Line Lift

54 Erection Stresses with 1.2 Handling Factor

55 Factored Erection Moments - Ultimate Capacity Check

56 In-Place Loads for Load-Bearing Panel:

57 Applied Loads: -Wind - Gravity (Roof) - Earth Pressure

58 Account for Differential Temperature Strains

59 Service Wind Load Moment Diagram

60 Service Wind Load Stresses

61 ACI 318 Section : The maximum deflection due to service loads, including P-Delta effects, shall not exceed L/150.

62 Differential Temperature Strain Moment Diagram

63 Differential Temperature Stresses - Note Panel Bow

64 Ultimate Capacity Interaction Curves - Dead + Live + Wind

65 Ultimate Capacity Interaction Curves - Temperature Strain

66 Relevant ACI 318 Code Sections: , : Column ties not required when flexural tension controls : Maximum height/thickness ratio of 25:1 can be waived when structural analysis is done (P-Delta) , , : Minimum transverse reinforcement ratio of can be used (instead of 0.002) : Shear walls do not usually need any shear reinforcement : Must use a 2nd order non-linear analysis including cracking when kl/r > 100

67 Individual Shear Wall Design Examples Linked

68 Design Tips to Save $$: - Use repetition to reduce form changes - Use Precaster s library of standard connection details - Anticipate erection sequence to minimize move-ins - Use modules for bay spacing: 42 or 48 for 12 wide panels 40 or 50 for 10 wide panels

69 Design Tips (continued): - Punched openings preferred over pork-chops and C-shapes:

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71 Hung Panels over Dock

72 Rabbet at Top of Panel for Bearing Steel Bar-Joist

73 Continuous Joist Bearing Angle

74 Individual Joist Bearing Angles

75 Cast-in Deck Bearing Ledge

76 Beam Bearing Pocket

77 Nut-Type Slotted Tie-back Connection with Threaded Rod

78 Slotted Tie-back Connection with Strap

79 Knife-Edge Embedded Plates Bearing on Column Haunches

80 Steel Bearing Tube Haunch in Form

81 Hung Panel Rotation

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84 Preferred Base Detail to Prevent Potential Water Infiltration at Floor Level

85 Pub. JR-403

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