What Causes Pavement Failure in Houston and How to Prevent It

What Causes Pavement Failure in Houston and How to Prevent It

With proper care and maintenance, commercial-grade pavement should last 30 years or more. That’s true for both asphalt and concrete, but it’s only true if the pavement is installed and maintained properly.

Without pavement construction expertise, early failure – and expensive replacement – is common. That’s especially true in cities like Houston, where heavy traffic and a punishing climate puts additional stress on pavement.

Here are five common reasons why pavement may fail early in Houston and what property owners can do to avoid those risks.

1) Poor Installation Methods or Materials

Depending on the project’s scale, site clearing, grading and soil stabilization may all be required before any pavement can be mixed and installed. There’s also proper mixing, forming, and curing, along with jointing, compaction, and finishing.

In short, there are a lot of potential failure points if an inferior crew is on the job. And a less experienced, less reputable crew is also more likely to use lower quality materials.

Whether the problem lies with the material or the process, the signs of low-quality construction will begin appearing soon after installation. Cracking, depressions, rutting, and surface aggregate loss are examples, and all are threats to the pavement.

The only way to avoid these costly problems is to invest in quality pavement construction from the beginning. This means selecting a contractor with engineering expertise, site planning experience and a skilled construction crew. Reputable teams like these succeed through quality work and therefore use quality materials.

2) Issues with the Base Soil

The pavement’s base is composed of soils that provide support and additional load-bearing capacity for the pavement. It’s critical that your pavement contractor knows what type of soil they’re working with. With experience, contractors get a sense of what soils are prevalent in their service area. In Houston, for example, large parts of the city sit on clay-rich soil. Termed “black” or “gumbo,” these soils soak up a lot of water, so they tend to shift during heavy rain (expansion) and when the water evaporates out (contraction).

Houston’s iconic pattern of heavy downpours and sizzling temperatures is the perfect recipe for soil shifting. Pavement exposed to base shifting will crack, heave, and develop depressions or potholes, which contributes to early pavement failure.

Because the base is like the pavement’s foundation, it must be thoroughly analyzed prior to construction. During the project, the soil may need to be stabilized using chemical additives and compacted to a sufficient degree. Reputable contractors will measure out their compaction work before moving forward to ensure it meets specified quality tolerances.

3) Inconsistent Maintenance

Quality construction and materials are a good start, but following installation, there is an ideal maintenance schedule to follow to keep the pavement in good condition. What constitutes ideal maintenance is a bit different for asphalt and concrete, as asphalt requires more regular maintenance. Here’s a quick comparison:

  • Concrete – One of concrete’s notable benefits is its low-maintenance nature. Concrete is a mix of cement, water, and rocks (aggregates). As such, it requires little upkeep throughout its life, but it’s important for owners to repair any damage as soon as it appears. Cracks that are spreading or widening are a major cause for concern, as is significant spalling, uneven pavement, or depressions.Aside from repair, occasional sealing (including the joints) may be all that’s required, along with frequent cleaning and restriping to ensure the pavement’s surface looks its best.
  • Asphalt – Asphalt is less expensive to install, but compared to concrete, it requires more care throughout its life. When asphalt is installed and every 2-3 years after that, asphalt should be sealcoated to protect it from wear, water, and weather. Asphalt sealcoat is an emulsion mix that mixes water, asphalt binder and an emulsifier. It can be sprayed or poured and broomed onto the pavement’s surface, where it will seep in and provide a tighter bond between layers.In addition to sealcoating, asphalt may require crack repairs, pothole patching, and a surface treatment or two before it reaches the end of its useful life. For commercial parking lots and high-traffic roads, the recommended surface treatment is usually an overlay. When overlaying, the pavement team will remove the worn surface layers of the asphalt, fix any base issues, and lay a new layer of asphalt over the existing base. It’s a cost-effective way to extend asphalt’s lifespan.

If maintenance isn’t scheduled when it’s needed, early failure is inevitable.

4) Extreme Temperature Swings

Houston is legendary for its heat, but fortunately, concrete and asphalt can handle the high temperatures. What pavement does have trouble with are big temperature swings. When it’s hot, pavement experiences thermal expansion. When it cools, pavement contracts. If this cycle repeats too quickly, the resulting stress may cause cracks and joint failures.

Proper jointing and curing processes will ensure the pavement can withstand thermal stresses.

5) Excessive Vehicle Loading

Heavy vehicle traffic may compromise the pavement if it’s not built to handle it. Alligator cracking, edge cracking and rutting are common signs of load-related failure, and there is often no fix other than to replace the pavement.

However, these problems can be avoided if the pavement is built to appropriate thickness, with appropriate rigidity (concrete) or flexibility (asphalt), with appropriate edge support, and appropriate curing processes.

Pavement Failure is Expensive, But the Expense Can Be Avoided

When commercial property owners invest in concrete or asphalt, they expect to get decades from their investment – as they should. But poor installation, inferior materials and delayed maintenance can all derail that investment and cause early failure.

To avoid this, property owners will need to prioritize a proven, expert Houston crew when choosing a contractor for pavement installation. And they’ll need to prioritize maintenance and repairs as their pavement ages through its lifecycle.