Maintenance and Repairs

September 22, 2021 Published by Golden Horseshoe Chapter - By Tim Van Zwol

Considerations for Condo Asphalt Pavement Repairs

From the Fall 2021 issue of the Condo News Magazine of the Golden Horseshoe Chapter of the Canadian Condominium Institute

One of the first impressions when arriving at a condo site is the condition of the asphalt pavements within the parking and drivelane areas of the property. Are potholes, surface wear with exposed aggregates, and cracking located throughout or is the area a well maintained surface of asphalt?

General maintenance and repair of asphalt pavements is typically lower on the priority list compared to more urgent roof and building envelope repairs for condo owners. Therefore, it is imperative for condo owners to achieve the full life expectancy out of their asphalt pavements by ensuring proper installation during construction and then addressing problem areas quickly.

Typical Asphalt Pavement Construction 

As a very brief overview – asphalt pavements typically consist of asphalt cement mixed with stone aggregates to create a homogeneous material. The asphalt pavement is typically placed in one or two layers above a thicker, compacted granular base that is designed to provide support and a drainage path for water.

Factors Influencing Asphalt Performance

One way to achieve the full life expectancy out of asphalt pavements is to ensure proper installation during construction. There are several factors at play during the initial installation and subsequent use that will impact the longterm performance of asphalt pavements:

• Initial engineering assessment, project design and proper specifications.
• Expertise of contractor and quality of initial installation during construction.
• Engaging 3rd party testing agencies during construction to confirm adequate material compaction and obtain asphalt samples for lab analysis/testing.
• Ensuring adequate sloping and drainage. Intent is for water to run off asphalt surfaces quickly to drains and to avoid water ponding.
• Traffic volume over time.
• Magnitude of wheel loading. For example, areas subject to repeated wheel loading from heavy garbage trucks will quickly lead to localized asphalt deterioration.
• Overall age of asphalt pavement and ongoing exposure to UV radiation and freeze-thaw cycles

Common Types of Asphalt Deterioration

All asphalt pavements, even if properly installed during construction, have a limited service life. Areas of deterioration will develop at a rate dependent on the factors listed in the previous section. The following types of asphalt deterioration are common and may be localized or observed throughout a pavement area.

• Longitudinal cracks. When asphalt pavement is initially placed, the width of the laydown strips is dictated by the size of the asphalt spreader. Longitudinal cracks may form at these joints if they are poorly blended/rolled together.
• Settlement and cracking of asphalt around catch basins will commonly form if granular backfill is improperly compacted during construction or if granular fines migrate into pipe joints over time.
• Alligator cracking. Typically caused by shrinkage of the asphalt pavement due to ongoing temperature cycles.
• Rutting and potholes. May be caused by localized settlement or low spots due to poor drainage and/or weak spots in the granular base.

Localized Repairs vs. Wholesale Replacement

It’s not a question of ‘if’ but ‘when’ and to what extent asphalt pavements will deteriorate over time. If a pavement system is properly installed and maintained, localized repairs may be required near the 5-10-15 year marks in high traffic areas and then wholesale replacement at the end of its intended service life (20-25 years).

Regular maintenance and/or localized repairs completed at 5 year intervals during the first three quarters of its lifespan will cost less overall and will be more effective in extending its overall service life. The quality of asphalt pavements will significantly decline beyond the 15-year mark if ongoing maintenance has not been completed up until this point. If one waits to complete localized repairs during the last quarter of the pavement lifespan, the repairs will involve greater areas and at a greater overall cost. The effectiveness of these localized repairs with this approach will be short-lived.

Localized repairs may include routing and sealing of longitudinal cracks or full depth asphalt patch repairs at rutting/ potholes. Asphalt milling & overlay is also a viable option to extend the service life of the system when the surface is worn, but the base is in good condition.

Wholesale replacement would typically involve complete replacement of the asphalt pavements and may involve replacement, re-sloping, and re-compacting of the supporting granular base layers.

Get Expert Advice

An engineer can assist with the initial design and construction review of a new asphalt pavement project. An engineer can also provide a condition assessment to review the extent and severity of deterioration and estimate the remaining life span. It can be determined whether localized repairs are sufficient or if wholesale replacement is warranted based on this assessment and anticipated costs. An engineer can also assist with these next steps to ensure the repairs are done properly.

By ensuring proper installation during construction and then addressing problem areas quickly with targeted repairs, condo owners will maximize the service life of their asphalt pavements.

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Tim Van Zwol, P.Eng. is Regional Manager/Associate with Read Jones Christoffersen Ltd.