Entry Event

10 minutes

The facilitator reviews the previous sections. The facilitator asks student “what have you learned about the reinforcing sand? What are some conclusions about how to add reinforcement to make sand strong? Do you remember what we did last time? Who can tell me what you have learned about the placement of the reinforcement materials? Today we will think about the placement of the reinforcement again. When we have two layers of reinforcement, where do we place the materials to get the most strength?”

Placement of Reinforcement: Two Layers

Small-group Hands-on Scientific Inquiry (40 minutes)

Students will experiment with the placement of the materials again, with two layers of reinforcement. The facilitator reminds students “It is important that you follow the instructions on the worksheet to document your observations”. The facilitator hands out the worksheets.

The facilitator asks the guiding questions:

• Will the placement of the reinforcement make a difference on the sand strength?

• Where do we place the reinforcement for the strongest sand?

Directions

Case 1: Two layers of reinforcement on the bottom

1. Label the container 2″ from the bottom

2. Pour the sand into the container until it reaches 2″ high

3. Place the wire mesh on the surface of the sand

4. Label 2″ from the sand surface

5. Pour the sand until it reaches 2″

6. Place another wire mesh on the surface of the sand

7. Fill the rest of the container.

8. Guess and document the sand level when putting the weight on the sand

9. Put the weight on the sand

10. Observe and document the sand level

Case 2: Two layers of reinforcement on the top

1. Label the container 2″ from the top, and another label at 4″ from top.

2. Pour the sand into the container until it reaches 4″ from the top.

3. Place a wire mesh on the surface of the sand

4. Pour the sand until it reaches 2″ from the top

5. Place another wire mesh on the surface of the sand

6. Fill the rest of the container

7. Guess and document the sand level when putting the weight on the sand

8. Put the weight on the sand

9. Observe and document the sand level

Case 3: Two layers of reinforcement, one on the top and one on bottom

1. Label the container 2″ from the top, and 2” from bottom.

2. Pour the sand into the container until it reaches 2″ from the bottom.

3. Place a wire mesh on the surface of the sand

4. Pour the sand until it reaches 2″ from the top

5. Place another wire mesh on the surface of the sand

6. Fill the rest of the container

7. Guess and document the sand level when putting the weight on the sand

8. Put the weight on the sand

9. Observe and document the sand level

Case 4: Two layers of reinforcement place of your choice

1. Label the container ( )″ from the bottom and ( )″ from the top.

2. Pour the sand into the container until it reaches ( )″ high

3. Place the wire mesh on the surface of the sand

4. Pour the sand until it reaches ( )″ from the top

5. Place another wire mesh on the surface of the sand

6. Fill the rest of the container

7. Guess and document the sand level when putting the weight on the san

8. Put the weight on the sand

9. Observe and document the sand level

Resources

• • A box per small group

  • Wire Meshes

  • Sand

  • Brick or Weight

  • The Placement of Reinforcement with Wire Mesh Worksheet

  • Markers

Whole Group Discussion

15 minutes

The facilitator leads a discussion using the following guiding questions:

• What did you observe from Case 1 to Case 3?

• What did you learn from Case 1 to Case 3?

• What did you do for Case 4? Why? What did you find out?

• How can these ideas relate back to friction and density we learned last week? (not sure about this one)

• What can you conclude about how the placement of reinforcement impacts the sand strength?

The general conclusion from this hand-on activity should be that with single layer, the placement (top, middle, down) should not make much difference.