2. Objectives:
At the end of the lesson, students will be able to:
1.Name types of forces.
2.Name types of loads.
3.Distinguish characteristics of
primary materials in main
structural construction.
3. What is forces?
Definiton:
Any influence that causes an object
to undergo a certain change, either
concerning its movement,
direction, or geometrical
construction.
5. Types Of Forces:
TENSION FORCE (daya regangan)
1 Tension refers to when a
force is applied that pulls
outward against the face of
a structural element and
stretches it (e.g., stretching a
rubber band).
6. Types Of Forces:
COMPRESSION FORCE (daya mampatan)
2
Compression represents
when a force is applied
inward against the face of a
structural element, thereby
shortening it.
7. Types Of Forces:
SHEAR FORCE (daya ricihan)
3
Shear is when a force is applied
in parallel to the face of a
structural element at an angle
that is perpendicular to either
compression or tension forces.
8. 1. 2.
Dead load Live load
LOADS
4. 3.
Seismic load Wind load
9. Dead load What it means:
Forces incurred due to the
weight of all the materials
used in the construction of
a home.
E.g:
Roof, ceiling, floor, wall
& partition.
What it affects:
• A constant over the life
of the structure.
• Big impact on the long-
term deflection/
creep of framing
members.
10. Live load What it means:
Produced by the users of
a home.
E.g:
People, furniture,
storage items.
What it affects:
• Exert force on almost
all of a house’s
framing components.
• Goal: To design floor
systems that limit
deflection & vibration.
11. Wind load What it means:
+ve @ -ve pressures
exerted on a house when
it obstructs the flow of
moving air.
Act perpendicular to the
surfaces of a house
What it affects:
• Depends on: location,
height, roof pitch.
• Most sig. impact: roof
framing, overhangs,
large openings.
12. Seismic load What it means:
The inertial forces acting on
a house due to earthquake-
induced ground motions.
Act horizontally on each
element of the structure &
are proportional to their
mass.
What it affects:
• All components of a
frame.
• Shear-resisting elements
are most affected
13. Do you know
the
characteristics
of primary
materials in
main structural
construction?
14. 1 1. TIMBER
• The oldest of structural materials.
• The properties of timber are non-linear and
very variable, depending on the quality,
treatment of wood, and type of wood
supplied.
• Wood is strong in tension and
compression, but can be weak in
bending due to its fibrous structure.
• Reasonable cost, ease of working, attractive
appearance and adequate life if protected
from moisture and insects.
• Wood is relatively good in fire as it chars,
which provides the wood in the centre of the
element with some protection and allows
the structure to retain some strength for a
reasonable length of time.
15. 2. BRICKS
2
• A brick is a block, or a single unit of a ceramic
material used in masonry construction, usually
stacked together, or laid using various kinds of
mortar to hold the bricks together and make a
permanent structure.
• Made from: Various kiln-baked clay and shale
mixtures.
• Typically produced in common or standard sizes
in bulk quantities.
• Burnt-clay bricks have good resistance to
moisture, insects and erosion, and
create a good room environment.
• They are moderate in cost and have
medium to high compressive strength.
• Long lasting
16. 3 3. CONCRETE
• Made by: Mixing cement paste
(portland cement & water) with
aggregate (sand & stone).
• Concrete is used extremely
widely in building and civil
engineering structures, due to
its:
Low cost, flexibility, durability,
high strength, high resistance
to fire, strong in compression,
hardness, imperviousness and
mouldability.
• Flaws: Very weak in tension.
17. 1.Reinforced concrete
Reinforced concrete is concrete in which steel
reinforcement bars ("rebars"), plates or fibers
have been incorporated to strengthen a material
that would otherwise be brittle. In industrialised
countries, nearly all concrete used in construction
is reinforced concrete. Due to its weakness in
tension capacity, concrete will fail suddenly and in
brittle manner under flexural (bending) or tensile
force unless adequately reinforced with steel.
2. Prestressed concrete
Prestressed concrete is a method for overcoming
the concrete's natural weakness in tension. It can
be used to produce beams, floors or bridges
with a longer span than is practical with ordinary
reinforced concrete. Prestressing tendons
(generally of high tensile steel cable or rods) are
used to provide a clamping load which produces a
compressive stress that offsets the tensile stress
that the concrete compression member would
otherwise experience due to a bending load.
18. 4 4. STEEL
• Iron alloy with between 0.2 and 1.7%
carbon.
• Steel is used extremely widely in all types
of structures, due to its:
Low cost, high strength to weight
ratio, speed of construction, strong in
tension and compression.
Flaws: Weak in fires, very prone to
corrosion (rust).
• Steel is a ductile material, which will
behave elastically until it reaches yield
(point 2 on the stress-strain curve), when it
becomes plastic and will fail in a ductile
manner (large strains, or extensions,
before fracture at point 3 on the curve).
19. Stainless steel
• An iron-carbon alloy with a minimum of 10.5% chromium content.
• There are different types of stainless steel, containing different proportions of iron,
carbon, molybdenum, nickel. It has similar structural properties to steel, although
its strength varies significantly.
• It is rarely used for primary structure, and more for architectural finishes and
building cladding.
• It is highly resistant to corrosion and staining.
