The Nebraska Concrete & Aggregates Association (NC&AA) has one job: promote quality concrete. Everyone has something to learn about concrete whether you’re an architect, engineer, producer, contractor, and even an elementary student. The NC&AA Concrete 101 program started more than 15 years ago and is still one of the most entertaining ways to teach potential young concrete enthusiasts about basic concrete ingredients: cement, rocks, and water.
The Concrete 101 program starts out with a question: “How many of you have scraped your knee on a cement sidewalk? You have? Well then you must have been awfully dusty!” The NC&AA feels that if the students get one thing out of this program, it’s understanding the difference between cement and concrete. Then the students learn “Flour is to cake as cement is to concrete.” The program also emphasizes the importance of all the ingredients of concrete and most importantly, the significance of water. Too much water and the concrete will become weak. Then the kids put it to the test.
The students are paired up in the classroom and given a 1x1x16-inch concrete beam mold, and bag of sand and cement.
NC&AA volunteers go around the room recording how much water is added to each pair’s mix. Then the students mix the concrete and place their samples in the molds. Some “pour” the concrete in the molds, while others “pack” the concrete (depending on how much water they added). They write their name and water content on the molds and the beams are stored in the classroom for a one-week cure time.
The following week, the NC&AA recaps everything the students learned the previous week. NC&AA also show videos of how cement is manufactured and the versatility of concrete. Then the molds are stripped and the students are asked to come in front of the class to “break” their beams. The beams are supported on both ends while a bucket hangs from the middle of the beam. Half-inch rebar sections (weighing 1/2 pound each) are placed into the bucket to see how much weight the beam can handle. Each student records the amount of water in their beam and the amount of weight it took to break it. They learn that it takes just the right amount of water to make strong concrete that can be placed easily into the beam mold.
After 17 years of conducting Concrete 101 programs for fifth graders, NC&AA also has learned a few things … including that kids love to make a mess, kids love to break things, and kids love concrete!
Jereme Montgomery (email@example.com) is the executive director of Nebraska Concrete & Aggregates Association.