A Bridge to Somewhere

Your taskYou are a member of small company that is competing against other regional companies for the right to build a cement based bridge span for a pedestrian walkway over a creek on your school campus.

Outcomes of project

• You will construct a bid using resources available to you in the classroom.

• Your bid must include time and cost of materials that you use in your bridge/span

• Your final submission to be considered for the winning bid will cover a 2ft span and support 30 pounds. You must submit your bid with your structure.

• The winning bridge/span will be one that is the most cost effective and meets specifications.

Requirements

• Each team must construct a minimum of 3 separate spans.

• For each span, your must include:a. Materials (type and quantity)b. Cost & Timec. Data (stress test, weight of span, other

structural observations)d. Visual representation of datae. Summary evaluation of each separate span

Prior Teaching

Safety: Proper use PPE’sVocabulary:CompositeTension StressStrainDistortionBidEngineering

Prior knowledge:Principles of material science, characteristics of concrete, uses of concrete

Young’s Modulus

• Definition: How much something is going to stretch

• It was very difficult to measure in this lab!• The control and burlap did not flex at all.• The welding rods flexed, but when do you

measure?

Bridge Designs

Discussion Questions

• How does the design of the bridge affect the load carrying capacity?

• How does the distance of the span affect the engineering of the bridge?

• What might cause a bridge to fail?• How does the design of the bridge affect the

materials used in the making of the bridge?

Teacher Resources

• http://elearning.vtu.ac.in/16/ENotes/ConcreteTechnology/Unit5-NS.pdf

• http://www.cee.mtu.edu/~llsutter/classes/cet1141/pdf/mca1.pdf