The beginnings of cement go back to the ancient Roman aqueducts, butnow the stuff is the foundation of a new chemistry curriculum in Carroll County schools.
"There's a lot of chemistry in cement -- it doesn't just happen," said Bradley Yohe, Carroll's supervisor of science.
Students at the county's five high schools are taking chunks of the stuff they once played hopscotch on and figuring out things like how much trace iron it has, how dense it is or how much heat it emits as it hardens.
Yohe first approached David Roush, Lehigh Portland Cement's Union Bridge plant manager, about four years ago to develop an advanced chemistry curriculum.
Yohe also called on Diane Bunce,a chemistry professor and educational theorist at Catholic University in Washington. Bunce helped the Lehigh engineers and Carroll teachers refine lessons to make them more effective.
The local teachers who spent a year developing the curriculum and have been using it forthree years will be honored Friday at a luncheon at Martin's Westminster.
In addition to the several state and national conferences where they have presented their program already, they will speak March 26 at the National Science Teachers Association convention in Boston.
Yohe picked concrete and cement not just because of the proximityof Lehigh, but also because they encompass several concepts that need to be covered in the chemistry curriculum.
"We're teaching abstract chemical topics like analytical chemistry in a format and in a manner which they can identify with the real world," Yohe said.
Aside from water, no other substance in the world is more widely used than concrete, said John Lynam, a science teacher at North Carroll High School.
The lab work shows students how chemistry relates to the real world. For example, they learn about different densities of concrete. A heavier form would be suited for a house foundation, while a lighter formulation would be more appropriate for roof slabs, Lynam said.
North Carroll High School juniors Kristi Chatfield and Francine Hewes said they will never look at concrete quite the same way again.
"I thought it would dry faster -- cure faster," Chatfield said,correcting herself.
Concrete doesn't dry -- it cures. Once mixed with water, it emits heat and hardens.
Yohe said the class has erased common misconceptions. Although most people use the terms concrete and cement interchangeably, there's a difference: cement is one ingredient in concrete, which also includes sand, aggregate and water.
"The water actually stays in the concrete and forms a hydrate," Yohe said, noting that concrete poured into a container of water will get just as hard.
Since the early 1980s, schools nationally have been encouraged to seek partnerships with business and industry. While Carroll schools have gotten contributions in money or materials beforefrom local businesses, nothing has been quite as extensive as this partnership with Lehigh, Lynam said.
The company contributed more than $10,000 in sophisticated engineering books and materials, but also got involved in the teaching and curriculum development. Roush and his engineers have gone into the classroom and are on call to help teachers when they need their expertise.
The advantage to students, Lynam said, includes a closer look at an engineering career. Studentstaking the "Chemistry II" elective already are considering science or math majors in college.
Hewes and Chatfield are undecided about their career choices, but Hewes noted it will be difficult to get into engineering schools, which usually require high SAT scores. Lynam said this curriculum will help a student get accepted at a school.
"Most have an essay application. They can refer to this," he said.
Roush said the program offers his company an opportunity for public relations.
"We think it's a good chance to create a program in which students can learn some principles and practical aspects of chemistry," Roush said. "And they can find out something about cement, which we think is a pretty important business, but which very few people know anything about."