ohfhrigpigpgnrpignignroivnoinivnrinionfroignroivnoiviernvijirijirjroifrnvprivnoernvrijgtebgoubbutgrobopubrnvoirbvoibrubvrincaivninrbvornrinvrinvrinvirnarininvirvuvnrirnipvnrvnrunvinivnemreinviprngirpnvpinariqnvrpivnrvnrf Illustrations List of Illustrations xxxiii 20.43 Michael Pyatok, Tower Apartments, Rohnert Park, California, 1993. Photo: Courtesy of Michael Pyatok. 655 21 Into the Twenty-First Century 21.1 Herzog & de Meuron with artist/designer Ai Weiwei, Olympic National Stadium, Beijing, China, 2001–2008. Photo: REUTERS/Alvin Chan. 658 21.2 Samuel Mockbee and the Rural Studio, Mason’s Bend Community Center, New Bern, Alabama, 2000. Photo: Timothy Hursley. 661 21.3 Renzo Piano, California Academy of Sciences, Golden Gate Park, San Francisco, California, 2005–2008. Photo: © Lee Foster/Alamy. 662 21.4 Emilio Ambasz, ACROS Fukuoka Building, Fukuoka City, Japan, 1995. Photo: © Andrea Balzano. 663 21.5 Ken Yeang, Menara Mesiniaga (IBM) Tower, Subang Jayan, near Kuala Lumpur, Malaysia, 1992. Photo: Courtesy of Ken Yeang. 665 21.6 Ken Yeang, Singapore National Library, Singapore, 1998–2005. Photo: Courtesy of Ken Yeang. 666 21.7 Ken Yeang, Solaris Building, Singapore, 2009–2010. Photo: Courtesy of Ken Yeang. 656 Preface This book is about learning to understand our human-made environment. It is about archi tecture as a physical vessel, a container of human activity. But since architecture is a social activity, building is also a social statement and the creation of a cultural legacy. Moreover, every building, whether a commanding public structure or a pri vate shelter—whether a cathedral or a bicycle shed—is constructed in accordance with the laws of physics in ways that crystallize the cultural values of its builders. This book is an introduction to the artistic urge that impels humans to build, as well as to the structural properties that enable buildings to stand up. It is also an introduction to the silent cul tural language that every building expresses. This book, then, might be thought of as a primer for vi sual environmental literacy. I should clarify that this is not a history of archi tecture in the normal sense of the word. There is historical information in the second part of the book, but the first part focuses on how the aesthet ics of architecture influence our perception. The first edition of Understanding Architecture was published in 1993, and numerous additions were made in 2005 for the second edition. In this third edition, the material is brought up to date, in cluding developments since the opening of the new millennium. This restructuring, however, necessi tated rethinking how to tell the story of twentieth century architecture. Hence, there are now revised chapters on the development of Modernism: how it was defined in Europe in the first third of the twen tieth century, then how it was exported around the globe in the second third of the century, and, finally, how reu

1. Building structural systems
Lecture 5

2. Introduction
• Structural systems of a building support all loads
and resist all constraining forces that may be
reasonably expected to be imposed on them
during their expected service life, with out:
– hazard to users,
– dangerous deformations,
– excessive side sway (drift) or
• Loads and environmental forces acting on
structural systems are:
– gravity loads
– Live and dead loads
– wind/seismic loads
– expansion/contraction of material
– heat and cold
– moisture and precipitation

3. • The structural systems could be either concrete, steel, timber,
prefabricated element or a combination.
• The selection of the appropriate structural system or
combination of systems depends on:
– Soil conditions
– The program and concept (function of a building)
– Type of building
– Material delivery and construction timing
– Local construction capabilities and preferences
– Ease of construction and schedule
– Cost of the selected system
– appearance and aesthetic potential

4. Reinforced concrete structures
• Concrete is a product obtained artificially by hardening of the mixture
of
i. binding material (cement),
ii. fine aggregate (sand),
iii. coarse aggregate (gravel), and
iv. water, in predetermined proportions.
• The property of concrete depend on the characteristic of the
ingredients and the proportion of the mix.
• In mix proportioning workability, strength, durability and economy
should be taken into consideration.
• Reinforced concrete (RCC) is a concrete in which steel reinforcement
bars have been incorporated to eliminate the major weakness of
concrete (tensile strength).
• The number, diameter, spacing, shape and type of bars to be used
have to be designed.

5. • Advantages and disadvantages of concrete structures

6. REINFORCED CONCRETE STRUCTURAL MEMBERS
• A reinforced concrete structure is made up of many types of
reinforced structural members, including:
– footings,
– columns,
– beams,
– slabs,
– walls, and so forth
FOOTINGS
• Footings support the entire structure and distribute the
load to the ground.
• The size and shape of a footing depend upon the design of
the structure.

9. COLUMNS
• These are the vertical load
bearing members of the
structural frame which transmits
the beam loads down to the
foundations.
REINFORCED CONCRETE STRUCTURAL MEMBERS

10. REINFORCED CONCRETE STRUCTURAL MEMBERS
BEAMS
• These are horizontal load bearing members which are
classified as either:
– Main beams which transmit floor and secondary beam
loads to the columns or,
– Secondary beams which transmit floor loads to the main
beams.

11. REINFORCED CONCRETE STRUCTURAL MEMBERS
SLABS
• Carry the live loads of the building and transfer them
to the beams.

13. Steel structures
• Steel has the maximum number of properties which are not
found in any other materials.
– High tensile and compressive strength
– Ability to deform plastically with out damage
– Can be easily welded, forged and riveted
– Large displacement before collapse

14. • Steel is the only material which is equally strong both in
tension and compression.
• Steel is suitable for all construction purposes in the present
day practice.
– Steel bars are used as reinforcement
– Construction of steel bridges
– Construction of buildings
• Skeleton construction
• Long span construction
– Erection of towers, etc
• The construction of a framework of structural steel
involves two principal operation: fabrication and erection.

16. • Cold rolled sections: Cold-formed shapes are relatively
thin section made by bending sheet or strip steel in
roll-forming machines.
• door and window frames, partitions, wall studs, floor
joists, sheathing, and moldings are made by cold
forming.

17. • Hot rolled sections: these are structural steel available
in wide range of size, shape and weight.

18. STRUCTURAL STEEL CONNECTORS
• There are four basic connectors used in making
structural steel connections. They are bolts, welds, pins,
and rivets.

19. • Advantages and disadvantages of steel structures

20. Timber structures
• Wood has always been a very good construction material since
olden times. And it is still used extensively for construction
purpose, railways, furniture, formwork, miscellaneous purposes,
transportation.
• Wood that is suitable for structural work is called timber. It can be
used as:
– Beams, joists and rafters
– Studs and posts
– Girders
– Trusses
– Decking
– Piles
– Structural laminated members
• The qualities of timber depend upon:
-Type of tree -Maturity of tree - Time of felling
-Method of seasoning -Type and process of preservation

24. THANK YOU

25. Quiz
1. Write down the advantages and disadvantages of :
 Concrete structures
 Steel structures
 Timber structures
2. What are the different loads and environmental forces
acting on structural systems?
3. Which construction material out of concrete, steel and
timber is mostly used in our country? why ?