13. Quick Video Facts
Texas built 15,000 bridges, which is two bridges per day for twenty years
– that is a lot of construction!
Bridges were built in response to a boom after World War II.
Better roads and bridges were needed to move more people and goods,
since current roads were unsafe.
More roads meant more traffic, people, and travel.
TxDOT had to think outside the box to design new bridges and help
connect communities.
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17. Quick Video Facts
Roads and bridges weren’t always as smooth as they are today.
Texas engineers tried new ideas to build bigger and stronger bridges.
Welding is a way to stick two pieces of metal together using a very hot flame
or electricity. This method of construction was a new technique used after
the war. It was made possible by many soldiers returning home who knew
how to weld from building steel ships and could put their skills to use.
Unfortunately, steel was hard to come by since it was used so much during
World War II. Engineers explored concrete construction for new bridges.
Engineers really thought outside the box. They used neoprene pads to
cushion bridges – the same material used in scuba suits and Band-Aids!
(break each bullet apart into separate slides add scuba steve)
17
18. Experiment
Let’s try an experiment to understand how concrete works and how it will
take on any form you put it in.
18
Editor's Notes
At some point, each and every person has used a bridge. Maybe you traveled over one while riding in the car without realizing it, or perhaps you walked across a bridge while playing outside. Bridges are structures that allow people and goods to cross a body of water, open space, or even over other roads to avoid traffic jams.
In Texas, many bridges are built and designed by the Texas Department of Transportation (TxDOT). There are many types of bridges!
Arch bridges often look like they came out of a fairytale! Arch bridges have been used for hundreds of years given their strength and minimal need to materials. Arch bridges have a curved design and are made with wood, stone, concrete, and steel. This is an example of a stone arch bridge in Palo Pinto County.
Truss bridges are a structure connected by elements that form triangles. It is a very rigid structure that transfers deck load to a wider area, like the Piano Bridge in Schulenburg, Texas.
A truss bridge has exposed metal beams built in triangular configuration. Like arch bridges, the metal beams can be either completely below the bridge deck or the can be on either side of the bridge deck.
What you see here is a bridge widely used in Texas today . They call it FS Slab and Pan-formed Girder bridges. FS Slab brides are a flat piece of concrete that have a steel bar, called rebar, through it. It was different from other slab bridges because it had a very high curb that was poured with the slab. The high curbs helped to carry the people and cars crossing the bridge deck. This bridge was designed during a time when steel was expensive and hard to come by, after World War II.
Pan-formed Girders were also a new and unique design in reinforced concrete bridge design. Engineers created “pans” that were filled with concrete to create a mold for bridges. These pans could be used over and over!
Beam bridges have a simple design where a horizontal beam rests on vertical piers. Early beam bridges were often constructed with large stones and wood. Today, concrete is one of the main materials used to build these bridges. Concrete is cheap and easy to make. The more piers a beam bridge has, the stronger the bridge will be. Check out this beam bridge in Williamson County!
Beam and girder bridges have long parallel beams that are under the bridge deck.
We are going to watch a short video about how engineers in Texas have designed unique bridges to meet different needs.
What did you learn from that video?
Consider using the infographic to help students review what they learned.
For older students, consider asking them to write a few short sentences about what they learned before reviewing as a larger group
As TxDOT worked hard to build new roads and bridges, teams of engineers explored new designs that were bigger and stronger than ever. Why do you think they were trying to come up with new designs for bridges?
Let’s watch another short video to explore some of the materials and design used for Texas bridges.
What did you learn from that video? Review your materials brainstorm list from before to see if any of the materials you came up with are used in Texas bridges today. Consider using the infographic to help students review what they learned. For older students, consider asking them to write a few short sentences about what they learned before reviewing as a larger group.
The materials for bridges can also vary; common materials include wood, concrete, steel beams, and steel wire encased in concrete. New materials and designs were explored after World War II as engineers learned more about technological advances to make safer, bigger, and more attractive bridges.
Roads and bridges weren’t always as smooth as they are today.
Texas engineers tried new ideas to build bigger and stronger bridges.
Welding is a way to stick two pieces of metal together using a very hot flame or electricity. This method of construction was a new technique used after the war. It was made possible by many soldiers returning home who knew how to weld from building steel ships and could put their skills to use.
Unfortunately, steel was hard to come by since it was used so much during World War II. Engineers explored concrete construction for new bridges.
Engineers really thought outside the box. They used neoprene pads to cushion bridges – the same material used in scuba suits and Band-Aids!
