Plan Ahead for Street Preservation to Maximize Funding Dollars
With a pavement management plan, you can protect your pavement network and identify preservation needs before minor deterioration leads to the need for complete street reconstruction. Pavement faulting, differential movement, joint deterioration, poor drainage, and subgrade instability can all negatively impact pavement performance. In certain areas of the country with particularly hard winters, several freeze-thaw cycles over several months can accelerate these problems.
Using a database that combines pavement condition inventory, location, and historical information, along with analysis tools and prediction models, Snyder & Associates can help you develop a long-term pavement management plan. This plan will better leverage your budget and it provides guidance for using the proper sustainable preservation techniques.
Four Steps of Proactive Pavement Management
- Data Collection — Gather information and identify pavement age and history. Information can be logged into a spreadsheet, or a program such as MicroPAVER™ or dTIMS®. In Wisconsin, the WISLR system is an option for local governments.
- Condition Assessment — Inspect pavements by quantitatively measuring distress types and distress severity levels. Using a standardized rating scale, such as Pavement Condition Index (PCI), pavement sections will be ranked according to the quantity and severity of distress. Once PCI information is known, a map can be created to provide a visual representation of the areas with the greatest need for preservation.
- Approach Planning — Predict and model the future condition of the pavement network by applying different budget strategies or network PCI goals. Prioritize rehabilitation and reconstruction strategies to develop a Capital Improvement Plan (CPI) that will save money long term.
- Plan Implementation — Adoption of your CIP and annual preservation strategies to maximize the use of available funds.
Common Pavement Problems
Understanding the root cause of common pavement issues allows you to correct small problems before they become major concerns.
The strength of the soil below the pavement can impact pavement performance. Unstable soils must be prepared, conditioned, and sometimes stabilized with chemicals or man-made geosynthetics to achieve the desired performance. In some Midwest soils, drainage also plays a critical role in the stability of the subgrade.
Joint deterioration may be caused by one of many factors including an inadequate air entrainment system or insufficient pavement drainage. An incorrect water to cement ratio in the pavement or a failed joint sealant can also lead to premature joint deterioration.
Slab faulting occurs when one slab is higher than an adjacent slab in a roadway system. This can be caused by slab pumping, settlement, curling, or warping. Proper load-transfer design, construction, and a subdrainage system will minimize the potential for faulting.
Improper pavement thickness can lead to pavement failure from fatigue cracking. Moisture infiltration and continued freeze-thaw cycles can then accelerate the surface deterioration.
Sometimes distress is caused by an undesirable quality in pavement materials or a unique reaction between pavement materials. Proper quality certification of pavement materials and the use of supplementary cementitious materials minimizes the risk of material-related distress. Plus, there are treatment options and design solutions to minimize the potential for recurrence.
Innovative Pavement Rehabilitation Solutions
Snyder & Associates is committed to the use of innovative pavement technologies and can help you determine a plan of action that will work for your budget and capabilities. Depending on specific conditions of your pavement network, one or more of the following solutions may be appropriate for your rehabilitation needs.
Dowel Bar Retrofit
In order to prevent faulting and effectively transfer wheel loads across slabs, the installation of dowel bars at existing traverse joints or cracks is a common remedy. Dowel bars effectively “tie” two slabs together to help prevent faulting in the future.
Partial Depth Repair
A partial depth repair will restore structural integrity, improve ride quality, extend service life, and reduce load impact by replacing the upper portion of a deteriorated slab. The use of durable concrete mixes will ensure long-life pavement performance starting at the joints.
Diamond grinding restores smoothness, improves friction, and reduces noise by removing a thin layer of pavement from the surface. Another important effect of diamond grinding is the increase in surface texture and the resulting improvement in skid resistance.
Causing minimal construction disruption, an overlay of asphalt or concrete can extend pavement life and improve ride quality. This method is typically used when there is only minor damage to the existing pavement structure.
Decades of Pavement Rehabilitation Experience
Ankeny, Iowa — Snyder & Associates completed a comprehensive pavement analysis on over 50 miles of snow route pavements for the City of Ankeny. All pavement was inspected and ranked according to the Pavement Condition Index (PCI). Multiple funding scenarios were studied to determine the level of annual maintenance and rehabilitation dollars that would be needed to maintain a network PCI of 70 (satisfactory-fair condition).
Recommendations for capital improvements (including the type of repair or rehabilitation needed and the approximate cost) were also made. Recommended projects were then included in the city’s five-year CIP. Critical pavements were highlighted for immediate improvement. While these areas didn’t clearly demonstrate visual surface distress, problems with air entrainment were verified based on a petrographic analysis of pavement cores.
“The pavement management study completed by Snyder & Associates was concise, accurate, and effective. It enabled us (the city) to spend our limited street improvement budget on maintenance activities and replacement projects with maximum efficiency.” – Paul Moritz, Assistant City Manager
Clear Lake, Iowa — Snyder & Associates also conducted a pavement analysis and PCI rating on selected streets in Clear Lake. The analysis included the documentation of pavement history and the visual inspection of pavement surface distress. A PCI rating was developed for each of the studied pavements. A five-year CIP was developed, along with individual improvement recommendations and construction cost opinions. The City of Clear Lake has used the pavement management study to plan long-term pavement improvements.
“The pavement management services provided by Snyder & Associates was a benefit to the City of Clear Lake. They inventoried the condition of our street network and provided a prioritized list of recommended improvements. These services helped to complete our CIP and improve our pavement network overall.” – Joe Weigel, Public Works Director
Iowa State University, Ames, Iowa — Snyder & Associates developed a pavement management program for the institutional road system on the Iowa State University campus. The program utilizes MicroPAVER™ software and covers over 50 miles of pavement. Half of the University’s roads are inspected on a yearly basis. The program is then updated and a new network PCI is calculated.
Pavement data and analysis help to illustrate the consequences of current funding levels and also the funds needed to reach the PCI goal. The network PCI has risen over the past several years due to proper planning and management of improvement projects by the Facilities Planning & Management Department and the Parking Division. Our firm has also provided similar services for Iowa State University’s parking lot system.