Week 4

Session 1

Guiding Question

  • How can we make sand stand tall?

Subquestions

  • How do we make sand strong (reinforced sand)?

Outcomes

  • Students test how the number of layers and the amount of reinforcement in each layer affect the strength of sand.

CT Components

CT Language

  • Reinforcement, layers of reinforcement

Data Collection

  • Different layers with plastic sticks

Data Analysis

  • Results from different layers with plastic sticks

Problem Solving

  • Test & hypothesize results

Entry Event

15 minutes

A facilitator asks “What is reinforcement?” After taking some answers from the students, the facilitator says “Remember the activity we did using the pool noodles and the plastic sticks to make the noodles stronger?” “How does it apply to soil?” Take some answers from the students.

Then the facilitator says “Let’s watch (watch from start to 1'20'') to see the potential for a well-reinforced soil structure.” When you watch the video, think about the following questions:

  • In the real world (video), how does the reinforcement help make the sand stronger?

  • What types of reinforcements are used in the video?

  • What is the purpose of adding other materials into sand?

A facilitator asks students the questions again:

  • In the real world (video), how does the reinforcement help make the sand stronger?

  • What types of reinforcements are used in the video?

  • What is the purpose of adding other materials into sand?

After the discussion, the facilitator asks students what else they see. “What is the roller doing?” The facilitator leads them to talk about packing the sand. “Why do we need to pack the sand?” The facilitator could explain that only adding materials is not enough and there is a need to pack to make the sand dense. The facilitator could lead a discuss about the role of friction and density in reinforcement.

Layers of Reinforcement

Small-group Hands-on Scientific Inquiry 40 minutes

The facilitator says, “As you have seen in the video, engineers add materials in the sand to make sand stronger. Today, we will experiment with adding reinforcement to make our sand stronger. We will be examining how the amount of the reinforcement changes the sand strength. First, we will be testing the layers of the reinforcement. Then we will be looking at the amount of reinforcement in each layer.” “It is important that you follow the instruction on the worksheet to document your observation. The facilitator hands out the worksheets.

Activity Steps

For this activity, students will explore results of adding plastic sticks (as a reinforcement) without compactions at different layers of sand to make sand strong.

Directions

Case 1 (No reinforcement, no compaction): Students pour sand to fill the box. No reinforcement is added in this case. Students then put the weight on the sand and observe the sand level. Document their observation on the worksheet. After recording the observation, empty the box for Case 2.

Case 2 (Place 3-5 sticks in the middle, no compaction): Students will identify half of the box (horizontally). Students pour the sand until the box is half filled. Students lay 3 to 5 sticks on the surface of the sand. Then pour the sand to fill the box. Put the weight on the sand and observe the sand level. Students document their observation on the worksheet. After recording the observation, empty the box for Case 3.

Case 3 (Place 3-5 sticks on the ⅓ and ⅔ mark, no compaction): Students will identify and mark the one third and two third line (horizontally) on the box. Students pour the sand to the one-third mark, lay 3 to 5 sticks on the surface of the sand as the first layer of reinforcement. Students pour more sand until the two-third mark and lay 3 to 5 sticks on the surface of the sand as the second layer of the reinforcement. Pour the sand to fill the box. After the box is filled, put the weight on the sand and observe the sand level. Students document their observation on the worksheet. After recording the observation, empty the box for Case 4.

Amount of materials on each layer:

Case 4 (Double the sticks in the middle, no compaction): Students will identify the middle of the box (horizontally). Students pour the sand until the box is half filled. Students lay 6 to 10 sticks (double the amount from previous tests) on the surface of the sand. Then pour the sand to fill the box. Put the weight on the sand and observe the sand level. Students document their observation on the worksheet. After recording the observation, empty the box for Case 5.

Case 5 (Double the sticks on the ⅓ and ⅔ marks, no compaction): Students will identify and mark the one third and two third line (horizontally) on the box. Students pour the sand to the one-third mark, lay 6 to 10 sticks (as did in the Case 4) on the surface of the sand as the first layer of reinforcement. Students pour more sand until the two-third mark and lay 6 to 10 sticks on the surface of the sand as the second layer of the reinforcement. Pour the sand to fill the box. After the box is filled, put the weight on the sand and observe the sand level. Students document their observation on the worksheet.

Resources

  • 6 boxes (storage boxes? clear, ideally 12”x12”x12”), one for each group of 3 students

  • Sand

  • Plastic sticks

  • Weights

  • Tarp for sand cleanup

  • Layers of Reinforcement Worksheet

10 minute break

Whole Group Discussion

15 minutes

The facilitator leads a discussion using the following guiding questions:

  • What did you observe from Case 1, Case 2 and Case 3?

  • What are changes from Case 1, Case 2 and Case 3?

  • What did you observe as a result of these changes?

  • What did you observe from Case 4 and Case 5?

  • What are changes from Case 2 and Case 4?

  • What did you observe as a result of these changes?

  • What are changes from Case 3 and Case 5?

  • What did you observe as a result of these changes?

  • What can you conclude from this experiment?

The general conclusion from this hand-on activity should be sand will be stronger with 1) more layers of reinforcement and 2) more amount of reinforcement on each layer.

End of Session Reflection and Debriefing

5-10 minutes

Teacher briefly explains the computational thinking (CT) skill embedded in the Problem Solving Process Diagram. Using the problem solving process diagram, the teacher will ask students to identify what kind of problem solving skills/process/computational thinking they used in this session and explain how they used it. The following are some sample questions that can guide the debrief.

  • What did I learn today?

  • What problem solving skills/processes or CT components in this diagram did I use today?

  • How did I use the problem solving skills/processes/CT components?