Paving the way

Sharp-eyed students may have noticed subtle changes in the terrain of the Chico State campus recently. In some areas, flat pavement that once pooled up with rainwater has been replaced with a rougher variety that allows water to pass through it.

The new surfaces are the work of Chico State’s Concrete Industry Management program, which is making its presence known by swapping out some of the campus’ conventional concrete for a more eco-friendly variety, pervious concrete.

Along Big Chico Creek, for example, several parking spaces behind Glenn Hall have been repaved. The area was the ideal place to lay pervious concrete because of the way it soaks up water, allowing it to drain back into the soil, said Dirk Vanderloop, academic coordinator for the CIM program.

The special concrete forms an environment for bacterial microbes that can digest many toxins, thus preventing them from reaching the groundwater, Vanderloop explained. In the parking spaces, the new surface will filter out any oil or other harmful fluids that collect, allowing the clean water to filter down into the creek.

Another recent project using pervious concrete can be found near Warner and West First Streets in front of the university’s Langdon Hall. The material was poured over the site of a grassy area that had become a bald patch worn down over time by heavy foot-traffic of students headed to nearby buildings and crosswalks.

What once was a problematic area where rainwater trickled down from eaves of buildings and collected in muddy pools will now gather and filter the runoff, allowing it to settle back down into the underground aquifer. The appearance of the paved walkway is a little rougher because, unlike traditional concrete, it is porous.

“It looks like a big sponge,” said CIM director Kristin Cooper-Carter.

The project allowed seven staff members, three students, four faculty members and a large group of community members to get hands-on experience and certification for pervious concrete. In California, contractors must get certification to pour pervious concrete in part because of the permanent nature of the material.

“We have to make sure it looks good when it goes in the first time,” Vanderloop said.

Chico State is one of only four universities nationwide offering a Concrete Industry Management major, and is the only program to include in the curriculum a class on sustainability relating to the industry.

Where concrete historically has called to mind colorless urban wastelands devoid of trees and natural vegetation, in recent years the material has been generating interest in its potential to make everything we build, from roads to homes, more sustainable. One of the focuses of the CIM major at Chico State is making the developed environment mimic the natural one, including constructing roads and sidewalks that allow for more natural drainage.

Clearly concrete has the potential to alter the way we build things on ground, but it can also make construction of homes and businesses more sustainable. Walls can be constructed of concrete and Styrofoam, helping slow down heat gain and loss and allowing the buildings to stay cool in the summer and warm in the winter.

Concrete is also a recyclable material; foundations of demolished buildings can be mashed up into gravel to be used in the process of laying new foundations, and other recycled materials can be mashed up and mixed into the concrete. Cooper-Carter is working on a research project with students to determine how much waste concrete is currently being recycled.

The downside of concrete from a sustainability standpoint, says Vanderloop, is that making it takes a lot of natural materials such as sand and rocks. Additionally, mixing the needed cement requires a lot of time, and thus energy.

“Most people use ‘concrete’ and ‘cement’ interchangeably,” Vanderloop said, “but cement is actually the glue that holds the stuff together.”

At Chico State, the CIM program began offering classes last fall with a curriculum tailor-made to fit the needs of the concrete industry. Officials within the $200 billion industry recognized that it would soon be in need of young professionals to take over management positions and decided to seek out academia to create these individuals, Cooper-Carter said.

The major has generated interest because of its high budget for equipment and student scholarships.

Companies within the concrete industry have invested $3 million for the program’s start-up. Additionally, a majority of the 37 CIM majors at the university receive private scholarships of $1,000 to $5,000 from industry companies.

Many students, such as Alex Llamas, are attracted to the CIM major because of the seemingly endless uses of concrete as a building material, but especially its sustainable qualities.

“It just makes sense,” he said. “It just saves you a whole bunch of energy.”

Llamas was recruited at a concrete convention for an internship with ASI Constructors. The Chico State senior spent his summer building a hydroelectric dam in Missouri. The experience taught him a lot about the work environment out in the field, said Llamas, who is confident he’ll find a job after graduation because of the high demand in the concrete industry.

Given the benefits of pervious concrete, it’s a wonder the material isn’t used more often. However, many builders and manufacturers, as well as the general public, are not educated about the product. Because the manufacturing process of asphalt includes the use of petroleum, oil lobbyists keep the downsides of asphalt out of the limelight, said Cooper-Carter. If we reduce our use of asphalt, we will become less dependent on fossil fuels, she added.

Chico State’s students will help to spread the word about the benefits of concrete, starting on campus where they are planning another green project to spruce up the university: repaving the tennis courts. The project will be innovative because it is something that has not yet been done in the United States, Vanderloop said.

For years, the courts have been in a state of disrepair, completely unusable. Besides giving students recreational space, the tennis courts would also be environmentally friendly. The pervious concrete, as in walkways and parking spaces, will filter rainwater back into the ground. Also, the surface would not need to be painted because the color can be mixed into the concrete itself.

Traditional pervious concrete is rough, but there is a smooth coating that can be added to give the tennis courts a flat surface. There are existing outdoor pervious concrete courts in Europe that have proven ideal for rainy climates; because of the material’s capacity for drainage, no sloping of the court is required.

Because of its sustainable qualities and capacity for seemingly universal uses in the construction industry, concrete will continue to be a major industry, said Vanderloop.

“People don’t think of concrete as being a very sexy thing,” he said. “But it’s the second most consumed material [after water] in the world.”