InfrastructureRecycled concrete saves money
Purdue University civil engineers are working with the Indiana Department of Transportation to perfect the use of recycled concrete for highway construction, a strategy that could reduce material costs by as much as 20 percent; “If you are going to pave, you may have to remove the old concrete and break it into pieces anyway, so recycling makes sense,” one of the researchers says
Purdue researcher Jitandra Jain with specimen // Source: purdue.edu
Purdue University civil engineers are working with the Indiana Department of Transportation (INDOT) to perfect the use of recycled concrete for highway construction, a strategy that could reduce material costs by as much as 20 percent.
Concrete pavements are made by mixing cement with water, sand, and “virgin aggregates” obtained from rock quarries located in the proximity of the construction site. In Indiana most of these aggregates are quarried limestone. A Purdue University release quotes Nancy Whiting, a scientist with the Applied Concrete Research Initiative at Purdue’s School of Civil Engineering, to say that “Some parts of Indiana have plenty of quarries near highway construction sites,” said. “In other places, it’s more difficult to find quality aggregate. If you have to drive 50 or 100 miles to get a good quality aggregate, it’s going to be much more cost effective to use recycled materials by crushing the concrete you have in place.”
Whiting is leading the concrete recycling project funded by INDOT through the Joint Transportation Research Program with Jan Olek, a Purdue professor of civil engineering, postdoctoral research associate Jitendra Jain, and graduate research assistant Kho Pin Verian.
“If you are going to pave, you may have to remove the old concrete and break it into pieces anyway, so recycling makes sense,” Olek said. “And you avoid putting it in landfills.”
Jain gave a research presentation about the work earlier this month during a meeting of the American Concrete Institute in Tampa, Florida.
The researchers are testing concrete mixtures that contain varying percentages of recycled concrete. They also are developing cost-analysis software that will enable the state and construction contractors to estimate how much they could save by using recycled concrete. Crushing old concrete pavements into aggregate that can be recycled in new concrete can potentially reduce materials costs by 10 percent to 20 percent, depending on whether any quarries are located near construction sites.
