Written by Alyssa Burley.
Project Cornerstone's Crystal Howard and Alyssa Burley visited Ms. Huntington's advanced eight grade science class at Jean Farb Middle School on Wednesday, March 25, 2015.
After a brief presentation about construction aggregates, the class analyzed two samples of aggregates. One sample included river sand, while the other had beach sand. Using a sieve (i.e., a cylinder with a series of screens of varying hole sizes), the students tested the two sand samples to find out which one is better suited for making concrete. The sample with river sand had the least amount of very fine sand.
River sand is better suited for making concrete over beach sand because the very fine beach sand will absorb the water from the concrete mixture instead of the cement.
After the sieve analysis, the students made their own concrete using river sand, gravel, cement and water. They poured the wet concrete mixture into silicone molds of butterflies, bees, trucks and footballs. After the concrete cured, they were removed from the molds and were given back to the students to keep.