A testing method developed for seismic analysis of suspended plasterboard systems as a part of a Industry Defined Problem given by Saint Gobain in CEA Fest 2014 at IIT Madras
3. Plasterboard is basically an inner layer of gypsum
sandwiched between two outer layers of lining paper
including various additives in the gypsum layer.
4. Varying the weight and strength of the lining paper
gives the finished board different properties.
7. Grid – Introduction
A typical dropped ceiling
consists of a grid-work of
metal channels in the shape
of an upside-down "T",
suspended on wires from the
overhead structure.
Each cell is then filled
with lightweight ceiling
tiles or "panels" which
simply drop into the grid.
8. Grid – Sizes
United States:
Europe:
the cell size in the suspension
grids is typically either
the cell size in the suspension
grids is typically
2 ft. × 2 ft.
or
2 ft. × 4 ft..
600 mm x 600 mm
Ceiling tiles are
slightly smaller at
595mm x 595mm or
595mm x 1195mm.
9. Tile Types
Normal
Fire Rated
Acoustic
Provide only minimum
fire safety as required
by standards.
Do not enhance
acoustic performance
of the space.
A large variety of
surface finishes and
thicknesses is
available.
Fire-Rated systems
The sheets made for
consist of an aerated
acoustic performance
gypsum core with glass
enhancement are
fibres, water repellent
composed of a high-
and other additives
density gypsum core
encased in.
encased in a heavyduty linerboard.
10. Market Products
• CSR Gyprock: CSR Gyprock has developed a
wide range of decorative ceiling systems as
well as a large selection of fire and/or acoustic
rated ceiling systems to meet specific FRL Rw
and Sound Absorption requirements.
• BORAL: Boral offers products in 3 different
categories; Fire-Rated Ceiling Systems, Non
Fire-Rated Ceiling Systems and QuietZoneTM
Ceiling Systems.
11. Market Products
• Saint Gobain Gyproc: SG Gyprock offers the
most variety in terms of available products;
– Gypsum Plasterboard False Ceiling System
– Ecophon Ceiling Tiles System: These acoustic
ceiling tiles offer a noise reduction coefficient
(NRC) rating ranging from 0.90 to 1.00
– Gyptone Ceiling: Gyptone ceilings provide an
outstanding sound absorption ranging from 0.8
to 0.85 and eye-catching aesthetics
12. Installation methods and sample quantity specification
PLASTERBOARD
INSTALLATION
CEILING SYSTEMS
–
13. Grid System Types – 1
Flush Jointed Ceiling Systems
Flush Jointed Ceiling Systems utilise
standard plasterboard sheet which is
fixed to appropriately prepared framing.
Plasterboard joints are ‘taped and set’ to
form a smooth ‘flush jointed’ continuous
ceiling suitable for painting.
14.
15. Grid System Types – 2
Panel Ceiling Systems: These panels are generally placed in a
two-way grid which is suspended below floor or roof framing.
The pre-coated face of the supporting grid or edge profile of
the panels combine with various surface textures to form a
decorative feature ceiling.
16. Fixing Method Type – 1
Direct fixing:
plasterboard may be
fixed directly to
steel furring which
is held by
appropriate direct
fixing clips attached
to a structural
support.
17.
18. Fixing Method Type – 2
Resilient Mounts:
Resilient Mount may
be screw fixed
directly to the
underside of joists or
trusses using screws.
19.
20. Fixing Method Type – 3
Concealed Grid
Suspended Ceiling:
plasterboard may be
fixed directly to steel
furring which is part
of a concealed grid
suspended ceiling
frame.
21. Fixing Method Type – 3
Extensive attention to
detailing is paid
because a large variety
of suspension
mechanisms are
available and new ones
can be devised by
assembling the various
components together.
22.
23. Quantity Specifications
Component
Quantity Required
1 Advantage E
2.8/m²
2 Connect T24 or T15 Main runner, installed at 1200 mm centres (max. distance from wall 600 mm, can 0.9m/m²
be extended up to 1200 mm if no live load between Main runner and wall).
3 Connect T24 or T15 Cross tee, L=1200 mm, installed at 600 mm centres
1.7m/m²
4 Connect T24 or T15 Cross tee, L=600 mm
0.9m/m²
5 Connect Adjustable hanger, installed at 1200 mm centres (max. distance from wall 600 mm)
0.7/m²
6 Connect Hanger clip
0.7/m²
7 For direct installation: Connect Direct bracket, installed at 1200 mm centres
0.7/m²
8 Connect Angle trim, fixed at 300 mm centres
as required
9 Connect Shadow-line trim, fixed at 300 mm centres
as required
10 Connect E-plug (for Shadow-line trim)
as required
For suspended Ecophon 600mm X 600mm tiles
25. Standards/Protocols
•
ASTM E 564 – 06(2012): Standard Practice for Static Load Test for Shear Resistance of
Framed Walls for Buildings
•
ASTM E 72 – 13a : Standard Test Methods of Conducting Strength Tests of Panels for
Building Construction
•
ASTM E 2126 – 11: Standard Test Methods for Cyclic (Reversed) Load Test for Shear
Resistance of Vertical Elements of the Lateral Force Resisting Systems for Buildings
•
IS 1893 (Part 1) – 2002: Criteria for Earthquake Resistant Design of Structures
•
Uniform Building Code – 1997
•
International Building Code – 1998 Draft
•
Eurocode 8 – 1998 Draft
27. Terminology
• Ductility Factor (μ) — the ratio of the ultimate displacement (Du)
and the yield displacement (Dyield).
• Limit State — an event that marks the demarcation between two
behaviour states, at which time some structural behaviour of the
element or system is altered significantly.
• Failure Limit State — the point in the load- displacement
relationship corresponding to the last data point with the
absolute load equal or greater than 0.8 Ppeak.
29. Shear Strength of Connection
Both the wooden blocking shall be fixed and cycling load shall
be applied. The slippage of the connection and the ultimate
shear strength shall be recorded.
30. Shear Strength of Plasterboard and Frame
One of the wooden blocking shall be released and the other shall
remain fixed. Cyclic loads through one of the hydraulic actuators shall
be applied to record results.
31. Shear Strength of Plasterboard and Frame
The displacements of interest are relative displacement between
anchorages, slip between anchorage and the channels, and wall
diagonal length change (shear deformation of the plasterboard).
32. Cyclic Load Application – 1
Sequential Phased Displacements Procedure.
The TCCMAR procedure defines the concept of the First Major Event
(FME) as the first significant limit state that occurs during the test.
33. Cyclic Load Application – 1
Sequential Phased Displacements Procedure.
Consists of applying three cycles of fully-reversing displacement, at
increments representing 25%, 50% and 75% of the FME.
34. Cyclic Load Application – 2
Large Excursion Displacement Sequence
Follows the TCCMAR incremental displacement guidelines
but begins the test displacement at 200% of the FME.
35. Cyclic Load Application – 3
Reduced Cyclic Displacement Sequence.
The three cycles of displacement at 100% of the FME following the decay
cycles are removed within each displacement increment.
36. Calculations
The hysteresis curves for all three sequences shall be plotted.
Based on the observed hysteresis response curves, the initial and
the stabilized envelope (positive and negative) curves are
generated for each tested specimen
39. Problems in establishing relation
• The actual failure during an earthquake is
modelled on a system scale and not
component scale.
• The seismic zone classification is based on
perceptual intensities.
• The structural frame design equations, if
used on a component scale produce
erroneous results.
40. Seismic Zone Correlation
• The Peak Ground Acceleration (PGA) is a
measure of earthquake acceleration on the
ground.
• Unlike the moment magnitude scales, it is not
a measure of the total energy of an earthquake,
but rather of how hard the earth shakes in a
given geographic area (the intensity). This
value can be related with the MSK scale which
has been used to classify the seismic zones in
IS 1893 – 2002
41. Seismic Zone Correlation
• The test designed can simulate X displacement of ± 100 mm, horizontal
accelerations of ±14.715 m/s2 and velocities of 300 mm/s.
• Earthquakes of up to degree IX can be recreated using the equipment.
42. References
Other than those mentioned in the Standards section, the following have been
referred to:
•
•
•
•
•
•
•
•
http://www.gyproc.in/false-ceilings-professional.html
[2] http://www.ecophon.com/en/Product-Web/Advantage/Advantage-E/
[3] http://www.gyproc.ae/pdf/Gyptone_Board.pdf - Gyptone Boards, Tiles and
Planks Technical Datasheet
[4] Experimental Cyclic Racking Evaluation of Light-frame Wood Stud and
Steel Stud Wall Systems, PHRC Research Series Report No. 107
[5] IS 808 – 1989: Dimensions for Hot Rolled Steel Beam, Column, Channel and
Angle Sections
[6] IS 2095 (Part 1) – 1996: Gypsum Plaster Boards — Specification
[7] AD-AS264 261: Cyclic Load Testing of Unreinforced Masonry Walls
[8] Plasterboard Partitions Seismic Performance Evaluation via Shake Table
Test, G. Magliulo, C. Petrone, V. Capozzi, G. Manfredi, University of Naples
Federico II, Department of Structural Engineering, Naples, Italy