TCA is a 10-plus year supporter of the RMC Foundation with an annual pledge of $1000 to the Foundation. Through 2015, TCA has contributed $13,000 to the RMC Foundation. Director Sparkman also participated in the Foundation’s Walk for Sustainability in Miami (2015) and was one of the top fund-raisers for this walk.
TCA also has its own foundation – the TRMCA Scholarship Foundation – originally created to support our scholarship effort for the CIM program. Our foundation also supports Tennessee-based research efforts at Tennessee universities and is funded through an annual golf outing and individual donations. The 2015 golf event netted over $6,000 for the foundation’s ongoing scholarships and other efforts.
Research within the industry
Primary Research
TCA’s primary research for 2015 focused on the maintenance and cleaning of pervious concrete pavements. Maintenance of stormwater systems has been emerging as a “hot topic” in the stormwater community for both regulators and designers over the past few years and new stormwater maintenance agreements significantly increase the responsibility of property owners to properly maintain and operate the stormwater controls that are installed on their sites.
Several cleaning projects were completed beginning in January of 2015. The projects were executed using a cleaning system assembled from off-the-shelf components common in the pressure washing industry. Total cost of the system was about $20,000 (including a 6’ x 12’ trailer). Other systems are also commercially available and examples of various systems are included in the photo gallery below:
The three red barrels serve as the filtration system for the recovered water. Vacuum for the system is provided by the 23HP engine at the front of the trailer. The cleaning deck is driven by a pressure washer (not pictured) to provide water to the concrete surface that loosens debris and the dirty water is then sucked back to the filter cans to remove most of the sediment prior to discharging excess water.
Another shot of the system as we unload to clean a permeable paver system. Note the 275 gallon tote in the truck bed that insures a constant supply of water for the 7 GPM pressure washer and the electric generator being unloaded that insures electricity is always available for the pump out tank. Excess water is typically discharged into landscaping or turf near the pavement being cleaned.
The leaf vacuum pictured here is sometimes used for cleaning dirty pervious concrete but may be best utilized for regular maintenance as opposed to deeper cleaning. These units can be rented locally or purchased for under $2500. Pavements must be dry for this type of cleaning to be effective.
The three red barrels serve as the filtration system for the recovered water. Vacuum for the system is provided by the 23HP engine at the front of the trailer. The cleaning deck is driven by a pressure washer (not pictured) to provide water to the concrete surface that loosens debris and the dirty water is then sucked back to the filter cans to remove most of the sediment prior to discharging excess water.
Tennessee Parks and Greenways Foundation
Pervious Parking Lot
This lot was installed by TCA in 2013 and records were made of initial infiltration rates. The lot was cleaned in early 2015 and results were recorded before and after cleaning and then compared to initial C1701 infiltration rates. Click on titles below to see the reporting forms that we developed to give to owners as documentation of the cleaning process:
This shot is typical of the condition of this 20-year old pervious concrete at Finley Stadium. While there is significant clogging in some areas, the pavement still functions adequately in most areas.
Don Green, City of Chattanooga (left) and Brent Rollins, UT-Chattanooga (right) make preparations for pervious testing and cleaning of the Finley Stadium lot.
Alan Sparkman demonstrates the use of the TCA cleaning system to the audience. This section of pavement was heavily clogged and slow draining prior to the process but achieved an infiltration rate of over 600 inches per hour after cleaning.
This shot is typical of the condition of this 20-year old pervious concrete at Finley Stadium. While there is significant clogging in some areas, the pavement still functions adequately in most areas.
Finley Stadium
Parking Lot
A small section of this lot was cleaned as part of a demonstration for the City of Chattanooga. Mr. Brent Rollins with UT-Chattanooga provided research assistance and used results to append prior research he had completed on this same lot. This lot has been in service nearly 20 years with no recorded maintenance and no original infiltration testing was done. The lot responded amazingly well to deep cleaning and achieved a very high post-cleaning infiltration rate.
MTSU Commuter
Parking Lot
MTSU Commuter Parking Lot – This very large parking lot was installed in 2006 and combined parking stalls constructed of pervious concrete with asphalt drive lanes. The lot has been lightly used and is still in excellent condition structurally. Most of the lot continues to drain well in spite of no maintenance but some areas did show visible clogging from landscape islands and raveling of the asphalt drive lanes. Four different types of cleaning systems were used on this lot and at another older pervious parking area on campus and results were compiled by Dr. Heather Brown and can be accessed by clicking the links below:
The Bunyan BIRD is cleaning a designated area of the parking lot with the stopwatch running. Infiltration rates were checked before and after cleaning.
The TCA system is in the background after cleaning a section of a 10 year-old pervious parking lot adjacent to the CIM offices on the MTSU campus. Notice the distinct improvement in the appearance of the pervious that has been cleaned.
Numerous C1701 tests were run by student helpers employed by Dr. Heather Brown as part of the project.
The Bunyan BIRD is cleaning a designated area of the parking lot with the stopwatch running. Infiltration rates were checked before and after cleaning.
Results from some of these projects as well as some earlier cleaning projects were compiled into a presentation that was given by Director Sparkman first at the International Concrete Sustainability Conference and subsequently used as the basis for presentations at the 2nd Annual Municipal Wet Weather Conference (sponsored by EPA Region 4 and the International Erosion Control Association), the Tennessee Stormwater Association Annual Conference, the East TN Development Conference, and the Bunyan Pervious Roast. Click here to access Alan's presentation.