In addition, the project uses wicking drains, instead of pumps, to help remove water from the ground – these drains absorb the ground water and bring them to the surface naturally.
Much of the material that is on property is reused or recycled – for instance, the trees that were removed were made into mulch and used for erosion control. Concrete from Olive Boulevard and Ladue Road will be used for the new roadway base or for fill.

“We also reuse as much of the earth we excavate on the project as we can. This helps eliminate the need for hauling the earth off the project, which also reduces the need for trucking,” said Yeomans.

The department is also testing new technologies to make the project more environmentally friendly. Last summer, for instance, MoDOT tested a process to place concrete. This process, called two lift paving, lays down a thick layer of concrete and then immediately places a second, thinner “lift,” or layer of concrete on top of that thick layer. Concrete placed using this method is as strong as that used on standard concrete pours.

“What this process allows us to do is place two different concrete mixtures. On the Route 141 project, this will be used to test a special concrete additive that captures pollutants and breaks them down using sunlight. This photocatalytic, or ‘smog-eating’ concrete additive is expensive, so being able to place a large concrete mixture base and then place a thinner layer with the additive is very important,” said Yeomans.

MoDOT will test a 2,000 foot section of the new Route 141 with this smog-eating concrete. This type of concrete has been used successfully in Europe.