Written by Alyssa Burley.

On Tuesday, November 24, 2015, Project Cornerstone’s Crystal Howard and Alyssa Burley visited 18 juniors and seniors at Diego Valley Charter School in El Cajon, CA.

Students learned about the construction aggregates industry (i.e., sand, gravel and crushed stone) and how they are used to build roads, homes and schools in their community.

The in-class program begins with a lecture about the local construction aggregates industry and sand shortage.  Next, students complete a lab experiment where they analyze construction aggregate samples (one with river sand and another with beach sand) using a sieve.  After looking at the collected data, students determine which sand type is best for making concrete.  Students graph their data in a pie chart and solve a word problem.  Last, students make small batches of concrete and use silicone molds of owls, bees, trucks, cars, footballs and more to form their concrete.  Students are able to see the chemical reaction that transforms the concrete from a liquid into a solid.  Each student is able to take their concrete projects home as a souvenir.