Field trip provides concrete lessons

BROOKSVILLE

Concrete is everywhere: sidewalks, buildings, roads, statues and bridges. The limestone that goes into the cement that makes the concrete is a mined product and is found here in Hernando County. Cemex is one of the companies that extracts it from local quarries.

Limestone is part of the local geology, a subject studied recently by Gulf Coast Middle School seventh-graders. So, a visit to Cemex seemed like a good way to see how the rock is processed. Plus, it was a way to get an up-close look at local career opportunities.

The school's field activity program coordinator, Danny Jones, and field activity teacher, Mackenzie Simmonds, took 21 students to the plant.

"We're going to the plant today to see how cement is made and why it's so important," Simmonds told the children.

When they arrived at Cemex, they were greeted by environmental specialist Shelley Husky and environmental technician Nathan Sears. Remaining on their bus, the students set off on a tour of the vast plant and its quarries.

They bumped and bounced on dirt roads past house-sized piles of washed, crushed rock. More massive rock piles were covered in an immense, open A-frame building.

While they drove, Husky and Sears provided commentary about what they were seeing and why cement is important.

"Cement is the glue that keeps concrete together," Husky said.

She explained how limestone is combined with silica, aluminum and iron and treated with heat to create clinker, the product of the heating of those ingredients. Clinker is ground into a fine powder, sometimes with additions, like gypsum, and becomes cement, which is mixed with water and various aggregates to make concrete.

The students saw impressive machines digging for limestone and the huge trucks used to transport it. They also saw the plant's recirculation ponds. Sears explained that in the ponds, water is cleaned using gravity, and the plant uses it over and over.

Sears and Husky described the diverse population of animals that can be found within the complex. She and Sears said the animals they have seen at the quarry include alligators, birds, hogs, foxes, coyotes, deer, eagles, turkeys, vultures and even a bobcat.

"We want to make sure we live with nature here," Husky said.

After a stop for lunch, the students were turned loose on a sand pile to dig for fossils. The area is rich in limestone because Florida used to be underwater, leaving behind sea biscuits, sand dollars and other long-deceased sea creatures.

When they slowed down for lunch, the students had time to discuss what they had learned and what impressed them.

"Cemex makes a lot of stuff for us, like the materials they mine," said Maddi Walcott, 12.

Annabella Savelli, 12, said she learned that "everything — makeup and toothpaste — is made up of limestone, and they crush down the rocks, and the cement is the stuff they mix into concrete."