Bricks and Bridges: Which bridge is the strongest?

Purpose

I wanted to see how bridges hold up.

Hypothesis

I think that the arch bridge is going to be the strongest. Because it holds the most weight.

Materials

Procedure

  1. I researched these types of bridges: truss, arch, and beam.
  2. I took notes.
  3. I gathered my LEGO bricks to make bridges.
  4. My dad helped me make a beam bridge, an arch bridge, and truss bridge with my LEGO bricks.
  5. First I tested them with small, medium, and large toy dinosaurs.(See Data)
  6. Next I tied a string in the middle of the bridges and hung the grams.(See Data or Video)
  7. Then, I put the weights on the top of the bridges. (See Data or Video)
  8. I recorded the data for each bridge test.

Conclusion

My conclusion was wrong because the truss bridge holds a lot of weight.

Data

Test 1: Toy Dinosaurs
Triceratops
(140g)		 Indoraptor
(220g)		 T-Rex
(340g)
Truss Bridge stable stable stable
Arch Bridge It's stable It's stable It's stable
Beam Bridge Bridge is stable Bridge bends It kind of bends
Test 2: Hook weights suspended from string
200g 500g 1000g
Truss Bridge It doesn't bend It doesn't bend It bends a little
Arch Bridge It doesn't bend It bends a little It's bending a lot
Beam Bridge Doesn't bend It's bending a lot It breaks, the piers come unattached
Test 3: Hook weights placed on top of bridge
200g 500g 1000g
Truss Bridge It doesn't bend It doesn't bend It bends a little
Arch Bridge It doesn't bend It didn't bend It bends a little
Beam Bridge It is going to bend It is bending It is bending and comes undone

Videos