San Antonio, Texas
With 65,000 students, the North East Independent School District is the second largest district in San Antonio, Texas. NEISD strives to foster a culture of health and wellness. They offer a variety of resources and programs to help students, staff, families, and area residents take an active role in their personal health and wellness, including physical fitness.
In 2015, voters approved a $499.95 million capital bond fund. The bond program included funding for walking tracks at 44 elementary schools in the district. The 9-feet-wide, 675-feet-long tracks provide a much-needed outdoor recreation resource for the schools and nearby neighborhoods.
Parents Take Action
On their own initiative, parents in the PTAs at several schools had raised funds to install asphalt walking tracks. They proved to be a welcome addition to the schools and popular with
Not all PTAs at district schools could afford to raise the funds to construct their own tracks. To establish a district-wide walking track program, funding was included in the bond initiative.
Solving a Paving Problem
The soils in the area are heavily clay and highly expansive. Horizontal and vertical movements of the underlying soils due to expansion and contraction caused extensive "alligator" cracking in the asphalt of the PTA-funded tracks. The District's Construction Management Department had to repair those tracks and find a better paving material alternative for the new ones.
Could one paving material work for both the old and new tracks?
"Porous Pave XL is a 50-50 mix of granite aggregate and chips of recycled rubber. The rubber gives it enough flexibility to withstand movement of the substrate without cracking," said Dave Frazier, engineering sales manager, GeoSolutions, Inc., regional leader in ground stabilization, earth retention and erosion control and distributor for the material in Texas. "It is a pour-in-place material that could be installed on a base of crushed stone for the new tracks and over-poured over the old asphalt to seal cracks and establish a new paved surface on the older ones."
Paving the way for the paving solution
The project was divided into seven parts, each in separate bid packages. Each package was overseen by a different civil engineering firm. Two geotechnical engineering firms also lent their expertise to project planning.
According to Jorge Cabello, senior director, construction management, NEISD, the district arranged for GeoSolutions and the material manufacturer to conduct a learning session for all the engineers. In addition, prospective contractors were required to take a four-hour training class to become certified installers.
The winning contractors were R.L. Rohde General Contracting, Inc., Adkins, Texas, and Jerdon Enterprise, L.P., Stafford, Texas. "With the training, they were better prepared to do a better job and get better results with fewer problems," said Cabello.
Assessing the results
"The permeable pavement has 27 percent void space. It allows up to 5,800 gallons of rainwater per hour per square foot to permeate down into the ground," said Frazier. "Even in heavy rain, the tracks drain quickly. No puddles on the surface."
The recycled rubber chips in the material make it slip-resistant. That adds to the safety of the surface.
Available in a variety of colors, the standard green was selected for the project as it is appealing to the eye and harmonizes with adjacent landscapes.
According to Cabello, the product was easy to install, and the finished tracks are attractive. Most importantly, the walking tracks have been well-received and are enjoyed by students, staff, teachers, parents, and neighbors.
Dave Ouwinga, president of the material manufacturer, noted an additional, environmental benefit. "The NEISD project was so large that 340,000 square feet were installed," he said. "Our permeable material for the paved tracks incorporated more than 1.4 million pounds of recycled rubber."
As seen in LASN magazine, November 2019.