Making "Magic" Sidewalks of Pervious Pavement
Students use everyday building materials—sand, pea gravel, cement and water—to create and test pervious pavement. They learn what materials make up a traditional, impervious concrete mix and how pervious pavement mixes differ. Groups are challenged to create their own pervious pavement mixes, experimenting with material ratios to evaluate how infiltration rates change with different mix combinations.
Students use inquiry-based learning methods, mixing different combinations of materials, to create their own "magic" sidewalk material.Copyright 2013 Ryan Locicero, WARE raingardens.us (author)
Civil engineers design the roads and bridges that we drive on. When it rains, stormwater collects on these roads and must be managed. Historically, roads have been designed with impervious materials, which means water cannot pass through them, rain and snowmelt runs off their surfaces, becoming stormwater runoff. By applying low-impact development technologies, engineers can manage this stormwater at its sources (where the precipitation falls) in innovative ways. One approach is to enable the water to infiltrate through the road surface into the underlying media layers. This requires engineers to design pavement that permits the passage of water, which is referred to as a pervious surface.
Replacing impervious surfaces with pervious surfaces such as porous concrete or asphalt enables infiltration and percolation of stormwater into the ground and provides a cleansing treatment for pollutants at the source location. This approach to stormwater management provides solutions to grand challenges for engineers and creates a more sustainable human/nature partnership.
After this activity, students should be able to:
- Explain the materials that make a traditional concrete mix and how pervious pavement differs.
- Evaluate different ratios of materials to predict how infiltration rate changes with different mix combinations.
- Use everyday building materials to create pervious pavement.