Pavement Management Benefits Campus Terracon brings cost savings, better pavements to complex campus system with pavement maintenance By Jennifer Tran, P.E.
Managing more than 15 million square feet of pavement would be a daunting task for any facilities team, but it’s especially complex when 32 campuses and 16 facilities managers are involved. This is the scenario for a client of Terracon Consultants Inc., headquartered in Olathe, Kansas. The client is Maricopa County Community Colleges, the largest U.S. community college network. Based in Tempe, Arizona, the Maricopa County Community College District (MCCCD) includes 10 regionally accredited locations serving more than 200,000 students each year. Successful deployment of a long-term pavement management plan has resulted in substantial cost savings and operational efficiencies for the college network. This systematic approach allows for consistent field data collection and processing. The plan is built upon annual evaluations of pavement condition based on regularly scheduled inspections of sample units at the network level and project level. For each sample unit, the Terracon team determines the type, amount and severity of pavement distress present. Distress survey information is entered into software to determine pavement condition indices (PCI) and ratings for each pavement.
M
Standard PCITM Rating Scale
Suggested Colors
100
Good
Dark Green
85
Satisfactory
Light Green
70
Fair
Yellow
55
Poor
Light Red
40
Very Poor
Medium Red
The Hawaii Asphalt Paving Industry (HAPI) association shared this graphic that shows the pavement condition index (PCI) rating scale, which Terracon and agencies use to assign actionable values to pavements.
Based on the PCI, the team prioritizes pavements into four categories that need various levels of maintenance or rehabilitation. The results of the PCI and the recommendations are then used to develop a rolling five-year budget. As part of Terracon’s services, the team also prepares the plans, specifications and contract documents recommended in the management plan. Consistent with good pavement management practice, maintenance and preservation projects dominate the annual pavement program, which includes large areas of crack sealing and surface treatments. Because the work is on college campuses, construction occurs during Arizona summers when temperatures of the asphalt pavement exceed 155°F. Materials and application of products are specified to meet certain criteria (i.e. temperature) prior to placement.
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Crack mastic is used on cracks with widths greater than 1.5 inches. You can see it looks similar to crack sealant, but it includes aggregate and other modified materials.
Here pavement surfaces are cleaned and prepared for use of crack sealant. Crack sealant is typically used in cracks greater than 0.25 inches in width.
With extreme conditions in Arizona, asphalt pavements undergo large temperature fluctuation and can become distressed, and cracking in the pavement surface is the primary distress. Rubberized asphalt crack sealant, formulated for the Arizona climate, is used to seal cracks between one-quarter inch to one and one-half inches in width. Crack mastic products are also used. While crack sealant and crack mastic have the same objective, crack mastic sealant is typically used to fill cracks greater than one and one-half inches in width. Crack mastic sealant contains binders with aggregate, synthetic rubber polymers and other modifiers. As such, cracks should be wide enough to accept the pea gravel-sized aggregate and still provide a good bond for the sealant to adhere to each side of the crack. After
