MODULE 1

Question 1

The prime purpose of structures is to carry loads and transfer them to the ground. Structures may be classified according to use and need. A general classification is:

Answer 1

• residential
• commercial
• institutional
• exhibition
• industrial

Question 2

residential

Answer 2

houses, apartments, hotels;

Question 3

commercial

Answer 3

offices, banks, department stores, shopping

Question 4

institutional

Answer 4

schools, universities, hospitals, gaols;

Question 5

exhibition

Answer 5

churches, theatres, museums, art galleries, leisure centres, sports stadia, etc.;

Question 6

industrial

Answer 6

factories, warehouses, power stations, steelworks, aircraft hangers etc.

Question 7

bridges

Answer 7

truss, girder, arch, cable suspended, suspension;

Question 8

towers

Answer 8

water towers, pylons, lighting towers etc.;

Question 9

special structures

Answer 9

offshore structures, carparks, radio telescopes, mine headframes etc.

Question 10

loadbearing walls or columns in compression and walls taking in-plane or transverse loads. Construction is very durable, fire resistant and aesthetically pleasing.

Answer 10

MASONRY

Question 11

framed or shear wall construction in reinforced concrete is very durable and fire resistant and is used for the tallest buildings. Reinforced or prestressed, is used for floor construction in all buildings, and foundations are required for all buildings

Answer 11

CONCRETE

Question 12

loadbearing walls resist loads transmitted to them by floor slabs. Stability depends on gravity loads.

Answer 12

Gravity masonry structures

Question 13

a steel or concrete skeleton collects loads from plate elements and delivers them to the foundations.

Answer 13

Framed structures

Question 14

a curved surface covers space and carries loads.

Answer 14

Shell structures

Question 15

cables span between anchor structures carrying membranes.

Answer 15

Tension structures

Question 16

a membrane sealed to the ground is supported by internal air pressure.

Answer 16

Pneumatic structures

Question 17

Steel-framed structures may be further classified into the following types:

Answer 17

1. single-storey,
2. multistorey,
3. space structures
4. tension structures and cable-supported roof structures;
5. stressed skin structures,

Question 18

single- or multibay structures which may be of truss or stanchion frames or rigid frame of solid or lattice members;

Answer 18

single-storey

Question 19

single or multibay structures of braced or rigid frame construction

Answer 19

multistorey

Question 20

space decks and domes are redundant structures, while towers may be statically determinate space structures;

Answer 20

space structures (space decks, domes, towers etc.)

Question 21

where the cladding stabilizes the structure.

Answer 21

stressed skin structures,

Question 22

Buildings must be designed and constructed according to the provisions of a building code, which is a legal document containing the requirements related to such things as

Answer 22

Structural Safety
Fire Safety
Plumbing
Ventilation
Accessibility to the physically disabled

Question 23

AISC

Answer 23

American Institute of Steel Construction

Question 24

AASHTO

Answer 24

American Association of State Highway and Transportation Officials

Question 25

ACI

Answer 25

American Concrete Institute

Question 26

NSCP

Answer 26

National Structural Code of the Philippines

Question 27

It is determining and selecting the overall dimensions of the supporting frameworks or members in a structure. Here, we determine a required cross-sectional area for a certain structural member and select the safest dimensions based on this area. Also, in RC, we determine the required number of steel bar to be used on a member just to resist and safely carry the effects caused by loadings.

Answer 27

STRUCTURAL DESIGN

Question 28

Structures are designed to resist many types of loads including dead loads, live loads, wind loads, and earthquake loads. The complete design must take into account all effects of these loads, including all applicable load combinations.

Answer 28

Loads and Stresses

Question 29

to be assumed in design consists of the weight of steelwork and all material permanently fastened or supported by it.

Answer 29

Dead Load

Question 30

must be that stipulated by the applicable code under which the structure is being designed or that dictated by the conditions involved.

Answer 30

Live Load

Question 31

For structures carrying live loads which induce impact, the assumed live load must be increased sufficiently by the percentage provided in the given table below.

Answer 31

Impact loads

Question 32

STEEL COMPOSITION & GRADES Structural steels can be grouped according to their composition as follows:

Answer 32

1. Plain carbon steels 2. Low-alloy steels 3. High-alloy or specialty steels

Question 33

mostly iron and carbon, with less than 1% carbon.

Answer 33

Plain carbon steels

Question 34

iron and carbon plus other components (usually less than 5%). The additional components are primarily for increasing strength, which is accomplished at the expense of a reduction in ductility.

Answer 34

Low-alloy steels

Question 35

similar in composition to the low-alloy steels but with a higher percentage of the components added to iron and carbon. These steels are higher in strength than the plain carbon steels and also have some special quality, such as resistance to corrosion.

Answer 35

High-alloy or specialty steels:

Question 36

PROPERTIES OF STEEL

Answer 36

Yield Stress Tensile Strength Modulus of Elasticity Ductility Toughness Weldability Poisson’s Ratio Shear Modulus

Question 37

is that unit tensile stress at which the stress-strain curve exhibits a well(defined increase in strain (deformation) without an increase in stress.

Answer 37

Yield Stress, Fy

Question 38

is the largest unit stress that the material achieves in a tension test

Answer 38

Tensile Strength, Fu

Question 39

is the slope of the initial straight-line portion of the stress-strain diagram. It is usually taken as 200,000 MPa for design calculation for all structural steel.

Answer 39

Modulus of Elasticity, E,

Question 40

is the ability of the material to undergo large inelastic deformations without fracture.

Answer 40

Ductility

Question 41

is the ability of the material to absorb energy and is characterized by the area under stress-strain curve.

Answer 41

Toughness

Question 42

is the ability of steel to be welded without changing its basic mechanical properties.

Answer 42

Weldability

Question 43

is the ratio of the transverse strain to longitudinal strain. Poisson’s ratio is essentially the same for all structural steels and has a value of 0 in the elastic range.

Answer 43

Poisson’s Ratio

Question 44

is the ratio of the shearing stress to shearing strain during the initial elastic behavior

Answer 44

Shear Modulus

Question 45

The steel enters to a continuous casting system where it solidifies and passes through series of rollers

Answer 45

Hot-rolled

Question 46

Bending thin material such as sheet steel or plate into the desired shape without heating.

Answer 46

Cold-formed