Download Grade Three Science Unit

Grade Three Science Unit
Building Materials
and Structures
SDES
Mrs. Turner
February 2012
Table on Contents
Page
2
3
4
5
6
7
8
9
10
11
Section
Glossary
Why do we build?
Who does the building?
What are building materials?
What are Structures?
Forces that effect Structures
The case of the 3 Little Pigs
What makes materials stronger?
Stability. Balance. Strength
What fasteners and Bonding Agents
work best?
12 Looking at Fasteners
13 Looking at Bonding Materials
14 Building My Tower
15 Bridges
16 Bridges
17 My Bridge Design
18-21 My Designs
Learning about Building
Structures Glossary
architect
Building
design/plans
structures
construction
Building
materials
fasteners
Bonding
agents
forces
Stability
Strength
balance
bridge
Why do we build?
Humans need shelter. We need a
place to protect us from the weather- keep us
warm/cool and dry. We have built structures
to protect us from war, disease, and invading
people and animals. So over
centuries humans have building
structures for their
families, animals, to worship
their gods, to make
transportation easier (roads and
bridges).
Who does the Building?
There are lots of people who are involved in the building man
made structures. The bigger the structure the more people
are involved. Here are some of the people needed:
























Architect
Building engineers
Draftsperson (Draughtsman)
Purchasing Coordinator
Project Assistant
Project Manager
Roofer
Safety Director
Safety Manager
Scheduler
Signal Worker
Site Manager
Superintendent
Surveyor
Welder Assistant Project Manager
Building Inspector
Carpenter
Civil Engineer
Concrete Laborers
Construction Assistant
Construction Coordinator
Construction Engineer
Construction Foreman
Construction Manager























Construction Superintendent
Construction Supervisor
Construction Worker
Contract Administrator
Contract Manager
Crane Operator
Dry Wall Finisher
Dry wall Installer
Estimator
Electrician
Equipment Operator
Field Engineer
Framing Carpenter
General Laborer
Inspector
Iron Worker
Joiner
Laborer
Master Electrician
Master Plumber
Painter
Pipe Fitter
Planner
What Materials do we
use in our Structures?
Materials can be grouped into four main
groups NATURAL, SYNTHETIC,
METALLIC and NON-METALLIC.
Most materials are available from manufacturers in common
regular forms. These include wire, sheet, plate, flat strip, round
and square bar, tube, angle, extruded sections, granules, chips and
pellets. The sizes of these have been decided by tradition.
In Canada we use a wide range of building materials. In
other countries, the materials used on their building maybe
different then our because of availability, cost, climate
conditions and cultural reasons.
Builders need to consider:
* What materials are best suited for specific
structures when building the frame?
*What materials are best suited for specific
structures when constructing the surface*What
conditions determine the materials
used
What are Structures?
They are all around us. They are everywhere we look and
everywhere we go. They come in all shapes and sizes. Some are made
by people, some are natural. Some are super ugly, others are simply
beautiful. We live in them, go to school in them, and drive in them.
They protect our heads from nasty bike crashes, keep our feet dry on
wet days, and make up the framework of our body. They are
mountains, spider webs, ant hills, beaver dams, and trees.
They're all structures. Think of structures as a combination of parts
that belong together. Take a look around you right now. How many
structures can you see? A lot, right? Let's take a look at just a few of
the millions of structures that surround us everyday.
A structure can refer to any type of object, be it natural or human-made. It
must support its own weight and whatever load is placed upon it.
Structures can be grouped into the following three broad categories:
Solid Structures are made from a solid piece of material, having little or no
space inside, e.g., solid rubber ball, hockey puck, stone monument, etc.
Frame Structures are made from parts joined together in a framework,
e.g.,construction crane, skeleton, suspension bridges, etc.
Shell Structures are held together by an outer “skin,” e.g., drink can, egg
carton, etc.
Many objects are a combination of a frame and shell structure, such as the
human body or a tent.
Forces that Effect
Structures
There are several natural forces
caused by our Earth’s gravity
that both architects and construction crews
need to keep in mind while building:
*Compression -squeezing *Bending
*Tension- stretching
*Shearingsliding
*Torsion-twisting
What are some other forces that builders have
to worry about?
_________________ _______________
_________________ _______________
_________________ _______________
It is important to know about the factors that
affect the buildings we live and work in, the
bridges we cross, and the vehicles we travel in.
Our safety is at stake.
Let’s look at these forces at Play
www.buildingbig
The Case of the Three
Little Pigs
Remember the story of The
Three Little Pigs.
• What caused the stick house to blow
down?_____________________________
____________________________
• Do you think it was a strong structure?
Why or why not?__________________
_________________________________
_____________________________
• Why didn’t the brick house fall down?__
_________________________________
_____________________________
• Can any forces knock down brick
houses?___________________________
_________________________________
___________________________
How do we make Materials even
stronger?
Materials can be made even
stronger by using cross-bracing or triangulation
to increase the stability of structures.
The triangle is a very strong shape and it is
often used to stabilize structures. Structures
made from many triangles put together are very
strong. Cross-braces are additional beams or
pieces that can be added on to a structure to
stabilize or strengthen it.
Stability. Strength.
Balance.
Stability deals directly with forces that
act on a structure and how they push or pull that structure.
It is important to know about the factors that affect the
buildings we live and work in, the bridges we cross, and the
vehicles we travel in. Our safety is at stake.
You can find out about the importance of stability on bridges
by going to the NOVA Bridges site. You might like to try the
Bridge Game.
We need to know how people can improve the strength of the
buildings and other structures in our lives.
Here is a website that gives you some information about the
world's tallest buildings.
Shape plays an important part in the strength of a structure.
Find out why a hen doesn't break her eggs when she sits on
them.
Looking at Fasteners
What are some others?
Fasteners and Their Uses
Fastener
Use
Possible other
use
I think we have so many different types of
fasteners because…
_________________________________
_________________________________
_________________________________
_________________________________
Looking at Bonding Materials
Let’s Try out some Bonding
Materials
Bonding Material
used
Tried on
Bond Didn’t
bond
Wood
Plastic
Metal
Paper
What worked best?
_________________________________
_________________________________
_________________________________
_________________________________
Let’s Build a Tower
I build that tower with:________
It was made with this many ________
It was ________ tall.
What could we add to make it even
taller:__________________________
_________________________________
Bridges
Why do we need bridges? Bridges make it possible to cross from one
shore of a river to another. Early man often placed stepping-stones in
the narrow sections of small streams as a way to get to the other side.
It is easy to see how a bridge might develop, using stepping-stones as a
base for logs or planks. The earliest bridge was probably a toppled tree
that had fallen across a nearby stream.
Are bridges always over water? No, they can be over other roads, over
railways, over deep gulleys. And they are not only for cars and people.
Wooden trestle bridges were essential to the passage of the railway
through the mountains in western Canada.
What is a truss?
Beam bridges can span a greater distance with a thicker beam. But
there is a limit, because too thick a beam will sag into the river. An
alternate solution is to build a beam of triangles, a "truss," which is
much lighter than a beam of similar thickness. A truss is extremely
strong and stable.
Does the bridge material make a difference in the strength of the
bridge?
Shape is important for strength, but so is the material. A steel beam
will hold more weight that a wooden beam of equivalent size. Today,
bridges are built of steel and reinforced concrete. Reinforced
concrete beams are created by placing steel bars into the concrete
before it hardens. This skeleton of steel helps the concrete withstand
the tension that develops when long, unsupported beams are subjected
to bending under heavy weight loads.
Bridges
There are 4 basic types of bridges.
Beam - The beam type is the simplest type of bridge.
The beam bridge could be anything as simple as a plank
of wood to a complex structure. It is made of two or
more supports which hold up a beam.
Arch - In the arch type of bridge, weight is carried
outward along two paths, curving toward the
ground.
Suspension/Cable-stayed - The deck (trafficway)
of a suspension bridge is hung by cables which
hang from towers. The cables transfer the weight to the towers,
which transfer the weight to the ground.
Cable-stayed bridges have towers, but cables from the towers go
directly to the road deck, instead of spanning
from tower to tower.
Cantilever - In the cantilever type of bridge, two
beams support another beam, which is where the
deck or trafficway is. The two beams must be
anchored, and this must be done well.
My Bridge Design
Materials used:_________________
_________________________________
_________________________________
_________________________________
How long?________ How wide?____
How many cars did it hold?_________
My Designs
My Designs
My Designs