In Mr. Dave Taylor’s Introduction to Engineering course, students have many experiences connected to solving real-world issues. In Mr. Taylor’s latest unit, he charged his students with designing a concrete bridge with the challenge of holding as much weight as possible while using as little material as necessary. Students were given one 80lb. bag of concrete and 8 yards of wire reinforcements.
The unit opened up with students researching the field of civil engineering, learning about salary, education required, and all of the sub disciplines. Mr. Taylor then had his students participate in the Question Formulation Technique (QFT). The QFT is an inquiry-based process that helps students generate many questions around a topic, or Q Focus. A Q Focus can be a statement, an image, a video, a song, or more, but it is never a question. The first time he did the QFT with students, he gave them a picture of a 19th Century aqueduct. This sparked many types of questions from students as they wondered about the construction, design, and history of the image. Once they were hooked, Mr. Taylor provided another Q Focus to get students to deeply think about their upcoming project: “We will build scale reinforced concrete bridges that accurately model real functioning bridges designed by civil engineers.” Students once again generated questions based on the statement, sparking their interest in the project at hand.
The students researched bridge design, including regulations from the Montana Department of Transportation and even the Government of the People's Republic of Bangladesh. From there, students engaged in the engineering design process. Working in groups, they made 3D models using Fusion 360 and continued to iterate their designs until they were satisfied with the finished product. One of the key challenges was figuring out how to make a mold to design their bridge, as they had to think about their design from a different perspective to design an inverse mold. Once they were finished, they went into Mr. Farrand’s wood shop with their final designs and physically constructed their molds with wood. Students determined how much water and wire reinforcement they wanted to use, where to place that reinforcement, and also considered how to remove their bridge from the mold without it sticking to the wood and cracking or breaking.
After a seven day curing process, students were ready to test out their bridges! Mr. Brisky came up with a chain hoist system as a way to evenly place weights on students’ bridges. Group A used 77.5 lbs. of concrete mix while Group B used 35.5 lbs. of mix. While Group A was able to hold 335lbs. compared to Group B’s 148.5lbs., Group B ultimately won because they held more weight with a lot less material.
Students were fascinated by this unit and want to try additional experiments, such as playing with the amount of water and reinforcement to see if they can improve their designs. Well done, panthers!
By: Brendan Keiser, CA BOCES Professional Development