What Causes Alligator Cracking in Asphalt? [And How To Solve It]  

Have you ever noticed large cracks in the roads around your home or along highways and wondered what caused it? If so, then you’ve seen alligator cracking. Generally speaking, these types of road surface damages are often created by certain weather conditions and traffic wear-and-tear over time—but there’s much more to this phenomenon than just that.  

In this blog post, we’ll be discussing the various causes behind alligator cracking and possible solutions for prevention and repair. So stick with us if you want to learn more about why alligator cracking is a problem for asphalt surfaces—and how to solve them. 

Understanding Asphalt 

Asphalt may be a common sight on roads and driveways, but what exactly is it? At its most basic level, asphalt is a mixture of stones, sand, and a binding agent called bitumen. This blend creates a durable surface that can withstand the weight of heavy vehicles and harsh weather conditions. In addition to paving roads and driveways, asphalt is used in roofing materials, insulation, and even waterproofing products.  

There are different types of asphalt, such as hot mix, warm mix, and cold mix. Each with unique characteristics and uses. Understanding the properties and applications of asphalt is integral to ensuring its longevity and quality in various construction projects. 

Alligator Cracking in Asphalt 

Alligator cracking is a type of asphalt damage characterized by a series of interconnected cracks resembling an alligator’s skin. This type of damage can significantly impact the durability of asphalt, compromising its structural integrity and leading to a shortened lifespan. Therefore, identifying alligator cracking early on is essential, as it usually starts as small cracks that eventually spread and worsen. Here are some of the most common causes of alligator cracking: 

1. Overloading: One of the primary causes of alligator cracking is the overloading of the pavement surface. When heavy vehicles pass over an asphalt surface, the pavement can be subjected to significant stress that it may not be able to handle. 

2. Poor Drainage: Poor drainage weakens the foundation of the pavement layers, leading to the pavement’s failure due to alligator cracking. The presence of water in the base and subgrade layers can cause soil erosion, resulting in the pavement’s instability. 

3. Poor Quality Materials: Using low-quality materials in pavement construction can lead to structural weakness, making the pavement more vulnerable to damage caused by environmental factors. 

4. Aging Asphalt: The age of the pavement is a significant factor that can lead to alligator cracking. Asphalts break down over time and become brittle, making the pavement more susceptible to cracking. 

5. Structural Weakness: Pavements with poor structural design are more prone to developing alligator cracking. The repeated stress of traffic loads can quickly cause paving failure, leading to alligator cracking. 

Preventing Alligator Cracking 

Can prevent alligator cracking by implementing the following measures during the design and construction of asphalt pavements: 

Proper Design and Construction of Asphalt Pavements: 

  • Adequate Pavement Thickness: The pavement thickness must be designed appropriately to handle expected loads. The thickness of the pavement depends on the expected traffic loads and the subgrade’s ability to support the pavement structure. 
  • Proper Drainage: Adequate drainage is necessary to prevent water accumulation and damage to the pavement structure. Proper drainage can be achieved through the use of gutters, ditches, and culverts, among other methods. 
  • Quality Materials: Using high-quality materials during construction can significantly improve the pavement’s durability and resistance to alligator cracking. Top-quality materials can withstand environmental factors, such as weathering, oxidation, and UV rays, without breakage or deterioration. 
  • Proper Compaction: Proper compaction of the asphalt layers ensures that the pavement’s structure is firm and that the material does not crack or break due to the stresses of traffic loads. 
  • Proper Mix Design: The right mix design of the asphalt pavement is critical to prevent alligator cracking. The mix design should consider factors such as the asphalt binder’s properties, aggregate gradation, and moisture content. 

Regular Maintenance and Repair of Asphalt Pavements 

One of the critical maintenance activities is crack sealing, which involves filling in cracks in the pavement surface to prevent water infiltration and damage. Patching is another necessary repair that can address potholes or other localized problems. More extensive damage may require resurfacing or reconstruction. Therefore, staying on top of regular maintenance and repair activities is vital to avoid costly reconstruction and ensure safe and reliable pavement conditions for years to come. 

Repairing Alligator Cracking  

Repairing alligator cracking is crucial for preserving the longevity and safety of asphalt pavement. Alligator cracking refers to a pattern of cracks resembling alligator skin scales. Here are some steps to repairing alligator cracking: 

Assessment of the Severity of the Cracking 

When repairing alligator cracking, it is necessary to assess the severity of the damage. Alligator cracking can be classified as either minor or major, depending on the extent of the damage. For minor alligator cracking, patching or resurfacing may be sufficient, while major alligator cracking may require full-depth reconstruction. 

Choosing the Right Repair Method 

Once the severity of the cracking has been determined, the correct repair method should be chosen. Some of the most common repair methods include crack filling, patching, resurfacing, and full-depth reconstruction. Each method has advantages and disadvantages, and the choice will depend on the extent of the damage and the budget available for repairs. 

Steps to Repairing Alligator Cracking 

The steps involved in repairing alligator cracking will vary depending on the chosen repair method. However, some general steps that may be involved include: 

  • Cleaning the damaged area thoroughly to remove loose debris and vegetation 
  • Saw-cutting and removing the damaged asphalt 
  • Preparing the base by adding new base material or compacting the existing base 
  • Applying a tack coat to ensure adhesion of the new asphalt material 
  • Placing and compacting new asphalt material 
  • Sealing the edges to prevent water infiltration and further damage 

Considerations for Repairing Alligator Cracking in Different Climates 

The type of repair method used for alligator cracking may vary depending on the climate. For example, in colder climates, it may be necessary to use hot-mix asphalt instead of cold-mix asphalt to ensure better adhesion and durability. Additionally, in areas with high precipitation rates, it is essential to ensure proper drainage to prevent water infiltration and further damage. 

Conclusion 

Alligator cracking can be a serious problem for asphalt pavement, and it’s essential to understand its causes, symptoms, and solutions to prevent further damage. By identifying these factors early on and regularly maintaining your pavement, you can extend its lifespan and reduce repair costs.  

And when it comes to equipment for your alligator cracking asphalt solutions, LeeBoy is the best choice, offering high-quality and reliable equipment to help you tackle any pavement repair job with ease. Trust in LeeBoy for all your paving needs.