Connections of earthquake resisting precast reinforced concrete building(en no 19565001)
1. Connections of Earthquake Resisting
Precast Reinforced Concrete building
- DHARMENDRA VANKAR
EN NO- 19565001
1
End Semester Exam
seminar presentation
Navrachana University
3. Introduction
• What is precast concrete?
• Advantages
• Case studies of precast buildings (India/abroad)
• Companies involved in precast buildings (India/abroad)
ELEMENTS OF PRECAST BUILDINGS AND VARIOUS
SYSTEMS
• Precast footings
• Beams
• Columns
• Slab
• Shear walls
• Partition walls
• Connection between precast elements
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• CONSTRUCTION METHODOLOGY
• DESIGN OF PRECAST BUILDING SYSTEM
• Loads (DL, LL, WL, EL)
• Analysis
• Design
• Detailing of reinforcement
• Cost estimate
• COMPARISON BETWEEN CAST-IN-SITU AND
PRECAST BUILDING DESIGNS
• PREPARATION OF MODEL OF PRECAST
BUILDINGS
(Scaled model / Prototype)
• STANDARDS
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Introduction
• WHAT IS PRECAST CONCRATE ?
Precast concrete is a construction product produced
by casting concrete in a reusable mold or "form" which
is then cured in a controlled environment, transported
to the construction site and lifted and set into place.
Source of an Image-
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6. Why precast-Advantages
PRECAST BUILDINGS
• Designed, manufactured, and tested
under supervision of experienced
management.
• Construction is faster.
• Production is not hampered with
weather delays.
• Environment –friendly.
• Greater flexibility : Design and
manufacturing at same location.
CONVENTIONAL BUILDINGS
• Concrete cast at site where contractors
do not take care of mix design
proportions.
• Construction is comparatively slower.
• Production is severely hampered.
• Non environment-friendly.
• Not flexible.
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7. Why not precast- DISADVANTAGES
• Very heavy members.
• Connections may be difficult.
• Somewhat limited building design.
• Joints between panels are often expensive and
complicated.
• Cranes are required to lift panels.
• Needs high labour and plant on site.
• Quality control is difficult.
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8. Precast concrete structural elements
• A precast building is constructed by assembling
and connecting various prefabricated elements
required in the building structure. These
elements are:
• Precast slabs
• Precast beams
• Precast columns
• Precast walls
• Precast foundation
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9. Precast slabs
• Precast slabs are cast in a factory environment
and include the following pressurised concrete
options.
• Hollow core units:
A Hollow core slab offers the ideal structural section
by reducing deadweight while providing the
maximum structural efficiency within the slab
depth. Precast floors are available with a variety of
factory-formed notches, slots and reinforcement
arrangements which offer various design
approaches.
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10. Diff type of slab
• Double-tee units
• Solid concrete units
• Biaxial voided slabs
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Double-tee units Biaxial voided slabs
11. PRECAST BEAMS
Beams and beam shells are both used for suspended flooring.
Beams are typically used as ledges for other forms of precast
flooring to sit on, but can also be used as a flooring option in
their own right. They are generally manufactured to suit each
particular situation and profiles can include.
• Tee-beams
• L-beams
• Rectangular beams
• U-beams and
• Beam shells
Beams can be either reinforced or prestressed.
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12. PRECAST COLUMNS
• Precast concrete columns are modular in design in order to be
made into different heights.
• Widths are 12", 18" and 24".
• Columns are not structural, but can be used as such
only after a structural engineer has adapted them to a
building.
• Precast column can be produced as either single
storey corbel column or multi storey corbel column.
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13. PRECAST WALLS
• A wall system can be comprised of :
• flat or curved panels (solid, hollow-core, or
insulated)
• window or mullion panels
• ribbed panels
• double-tee .
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14. PRECAST FOOTING
• Precast footings are a recent innovation.
• No holes need to be dug for footings, as the
precast blocks are set on grade, and the posts,
columns or beams fit in pockets cast in the
concrete block.
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15. TYPE OF PRECAST SYSTEMS
The type of structural system should be determined
keeping in mind
• the purpose of building,
• the efficiency of the system,
• the location.
• the client’s need.
Depending on the load-bearing structure, precast systems
can be divided into the follow categories:
• Large-panel systems
• Frame systems
• Slab-column systems with walls
• Mixed systems
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16. LARGE PANAL SYSTEMS
“Large-panel system” refers to multistory structures composed of large
wall and floor concrete panels connected in the vertical and horizontal
directions so that the wall panels enclose appropriate spaces for the
rooms within a building.
• These panels form a box-like structure.
• Both vertical and horizontal panels resist gravity load.
• Wall panels are usually one storey high.
• Horizontal floor and roof panels span either as one-way or two-way
• slabs.
• When properly joined together, these horizontal elements act as
diaphragms that transfer the lateral loads to the walls.
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Depending on wall layout, there are three basic
configurations of large panel buildings:
• Cross-wall system :The main walls
that resist gravity and lateral loads are
placed in the short direction of the
building.
• Longitudinal-wall system: The walls
resisting gravity and lateral loads are
placed in the longitudinal direction.
• Two-way system. The walls are placed
in both directions.
18. FRAME SYSTEMS
• Precast frames can be constructed using either linear
elements or spatial beam column sub-assemblages.
• The use of linear elements generally means placing the
connecting faces at the beam-column junctions. The beams
can be seated on corbels at the columns, for ease of
construction and to aid the shear transfer from the beam to
the column.
• The beam-column joints accomplished in this way are Hinged.
• However, rigid beam-column connections are used in some
cases, when the continuity of longitudinal reinforcement
through the beam-column joint needs to be ensured.
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20. CONNECTIONS
The definition of a ‘connection’ is the action of
forces (e.g. tension, shear, compression) and/or
moments (bending, torsion) through an
assembly comprising one (or more) interfaces.
• Connections are locations of high stress concentrations
and are weak points in the structural systems.
• Connections of different precast concrete components
like footing beams, columns, slabs and wall panels are
very essential in precast concrete building.
• Depending upon the type of connection, a joint can be
considered simply supported, fixed and hinged.
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21. CONNECTIONS
• Types Of Precast Connections:
1. beam-to-slab connections
2. beam-to-column connections
3. wall-to-frame connections
4. column splices, including to foundations.
Primarily precast building connections can be classified as:
• Typical European prefabrication.
• Equivalent monolithic moment resisting connection.
• Post-tensioned dry joint.
• The Precast Hybrid Moment Frame System.
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22. Typical European prefabrication
In this type of connection concrete structures are
designed with plastic hinges occurring at column bases
and beams are hinged to the column.
Advantages :
• increases speed of construction.
• high quality control can be maintained as all precasted
elements are required to be dry jointed at site.
Limitations :
• lack of lateral stability since beams and slab are simply
supported; moment resisting connections are required to
achieve adequate stiffness.
• not preferable as it causes significant deformation and
high lateral displacement during a seismic event.
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24. Equivalent moment resisting freames
• Precast concrete structures are traditionally
designed as moment resisting frames with plastic
hinges occurring at the column base, and beams
hinged to the columns.
• A ductile moment resisting connection between
the column and the beam can provide, with
respect to a simply supported precast beam, the
advantage of designing continuous beams with a
reduced beam depth, or with an increase of either
span length or carried load.
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25. POST TENSIONED DRY JOINT
• They show a good seismic behavior due to limited
residual structural deformations, which allow
immediate occupancy of the buildings after a seismic
event.
The post-tensioned tendons act as elastic springs
recentering the joint and in this way resetting the
initial conditions existing before the seismic event.
• In such connection a tendon is passed through the
connection and post-tensioned.
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27. The Precast Hybrid Moment Frame
System (PHMF)
• The precast hybrid moment frame (PHMF) system represents the
latest seismic-resistance technology (developed over the last fifteen
years) and is deemed to be one of the best performing lateral
resistance systems available today.
• Most seismic systems dissipate energy through yielding, and it is not
unusual for a building to lean after a major earthquake. As a unique
feature, the elastic, unbonded post-tensioning used in the PHMF
system is designed to overcome yielding in the frame and pull it
back to a righted position.
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28. Key Benefits
• Superior seismic performance in an earthquake compared to conventionally framed steel and
concrete structures. The precast ductile frame is designed to handle significant seismic drift while
experiencing minimal damage due to its post-tensioned, self-righting mechanism. Truly a
“resilient” structure.
• Better aesthetic appearance for the structure than other traditional frame and skin cladding
systems due to high quality integrated architectural precast finishes and the use of hidden
connections.
• Faster installation than other traditional frame and skin cladding systems.
• No interior shear walls or x-braces – allowing for greater interior visibility and security.
• Inherent fire-resistant qualities of concrete structure.
• Lower long-term maintenance, for both the exterior and interior.
• Superior vibration control (performance characteristics).
• Environmentally-friendly use of locally and regionally extracted and
• manufactured materials (concrete) vs. structural steel and fireproofing.
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31. CASE STUDY
• CUMMINS TECHNICAL CENTRE INDIA, KOTHRUD,
PUNE
• Concrete grade is M50. The precast column are three floor height
and the size is 900mm x 900mm and height is 10m.
• Precast Beams are sitting on the corbel introduced in the precast
column. There are pockets of 1m kept in the column at each floor
level in order to pass the continuous reinforcements of precast
beams. For internal column, after installation of all four side beams
and reinforcement passing in between the column pockets, then the
junction is done as cast-in-place.
• Elastomer pads are used underneath of precast beams for rotation,
lateral forces or vertical movement in the columns due to seismic.
• These are moment-resisting frame connections.
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33. Construction Method for precast
system
• All safety issues on site when handling precast elements,
• The lifting capacity of the crane used.
• The working boom-radius of the crane.
• The suitability of construction materials for the purpose
of use, i.e. sealant, grouting, shim plate, propping etc.
• Co-ordination with the precaster and specialist supplier
to achieve the best performance and working method.
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34. Sequence of work
QUICK CHECK
• Ensure the correct panel before hoisting.
• Ensure the crane lifting capacity before hoisting the
panel.
• Ensure the desired crane’s working radius.
• Ensure the anchorage for the propping does not damage
• cast-in building services.
• Ensure the desired verticality/position is achieved.
• Estimated time to install a typical precast element is 1/2
to 3/4 hour
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35. • Precast construction has many advantages over
conventional construction systems, but there are
also many areas where it does not perform well. One
major area where precast concrete does not perform
well is with seismic loading.
• Due to poor behaviour of precast structures during
earthquakes throughout the world, precast is viewed
as unsuitable for resisting earthquakes.
• Most of the earthquake related precast
construction failures have occurred due to poor
design, deficient diaphragm action, inadequate
detailing, and/or deformation issues.
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36. References
• IS 1893-1 (2002): Criteria for Earthquake Resistant Design of Structures
• FIB Bulletin-27, 2003. Seismic design of precast concrete building structures, International
Federation for Structural Concrete.
• IS 15916:2010, Indian Standard: Building Design and Erection using Prefabricated
Concrete Code of Practice, Bureau of Indian Standards, New Delhi.
• ACI 318:08 2008. Building Code Requirements for Structural Concrete and Commentary,
American Concrete Institute, USA.
• ANALYSIS OF PRECAST MULTISTOREYED BUILDING – A CASE STUDY” , Bindurani.P, A. Meher
Prasad, Amlan K. Sengupta (ICEE 2013)
• LITERATURE WORK STUDY OF PRECAST CONCRETE CONNECTIONS IN SEISMIC,
Dr. Sachin Admane,( GISI 2015)
• Tests on Connections of Earthquake Resisting Precast Reinforced Concrete Perimeter
Frames of Buildings, Jose I. Restrepo, Ph.D., PCI JOURNAL
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