How Does Subgrade Moisture Lead to Pavement Weakness?

The Impact Moisture has on Pavement

Poor drainage leads to excess moisture, creating a soft base layer. Without proper support, the pavement surface will sink as vehicles or other heavy loads pass over. Water drainage is vital to maintain structural integrity and, in turn, ensures your pavement lasts its expected lifespan. Anytime we see water pooling and soaking into the lower layers, we expect to see general erosion, cracks, and potholes appear on the surface. When drainage is insufficient, the pavement is more likely to experience premature subgrade erosion and damage to the surface. Asphalt roadways can last up to 3 decades when correctly cared for, but without proper subsurface drainage, moisture will cause severe damage in a short time. By hiring a professional asphalt business, you’re ensuring that your pavement will last for decades. Drainage problems are one of the worst problems to have with a new asphalt pavement. If you’re looking to have asphalt paved on a property or are in need of a consultation for pavement with drainage issues, contact Tolliver & Curl Paving today.

Why A Stable Subgrade is Important

The subgrade is the foundation of the pavement, ensuring that the surface remains durable and intact. Anytime a subgrade foundation isn’t properly prepared, we see cracking on the surface, which leads to rapid deterioration. A stable subgrade layer supports the roadway above, ensuring that the pavement is able to withstand the heavy load of traffic. Surface-level repairs are possible, but the base layer will continue to erode away. A team of professionals may be able to mitigate damage from the water collecting underneath the pavement, but this is costly and can easily be avoided with proper preparation of the base aggregate. By starting with a strong, dry, compacted subbase, the soil will prevent any weak areas from forming and will maintain a strong foundation. Ignoring the subgrade will cause problems to occur later on, which will never stop. In order to ensure a stable pavement, a stable subgrade must first be installed. To learn more about Tolliver & Curl’s services and how a professional pavement business handles subgrade installation while avoiding moisture retention, contact our offices today.

The Effects of Poor Drainage

Drainage is one of the most overlooked features when amateurs pour pavement. What may not seem like a critical step in installing pavement can be detrimental and cause premature pavement failure. The base layer of aggregate must be properly prepared to achieve adequate drainage. Soil is highly susceptible to erosion, which inevitably leads to surface problems. Without proper preparation, water and moisture will cause the subgrade layer to erode and break down over time. This will cause major problems, leading to cracking, weak top layers, and crumbling of the pavement.

How Water Content Can Break Down Pavement in Winter

When the subgrade layer of a pavement is not properly prepared, the subgrade is more susceptible to frost damage, which occurs during winter. As moisture soaks into the soil and becomes trapped, it expands as the temperature drops below freezing. This freeze-thaw cycle weakens the subgrade soil and the layers above it by pushing the materials apart from the inside out. If the subgrade materials are graded properly, water will flow away from the pavement, preventing it from getting trapped. Simple preparation of the subgrade soil increases the longevity of the pavement.

Correctly Preparing A Pavement Subbase

Subgrade preparation is a simple step when installing a new driveway or roadway, but if done incorrectly can have serious implications. Before a job, we evaluate the soil to determine the soil type and whether or not we expect to run into issues. We must understand the soil moisture content, stability, and whether the soil type can be sufficiently compacted. We then must remove anything unusable, including vegetation, topsoil, and any subgrade layers. The soil must be compacted properly to create a strong foundation. Water will struggle to penetrate correctly compacted soils, which reduces the likelihood that soil erosion will occur. By compacting the subgrade layer of soil, you are increasing the density, which improves stability and load-bearing capabilities. When dealing with fine-grained soils or other low-quality materials, over-extraction removes the existing soil and lets you apply more appropriate soils before compacting. When the quality of the existing soil is too weak, professionals may add stabilizers. Stabilizers can be made from emulsified asphalt, cement, and other chemical agents. When the soil is stabilized, it will resist water and moisture more efficiently. A granular base course can also be added to evenly distribute the weight of the load above. A granular base course is made of granular materials, compacted between the lowest subgrade layer and the pavement.

Repercussions of Poor Subsurface Drainage

Anytime a pavement has poor subsurface drainage, you should expect structural issues within a few months. This can change depending on the season in which the pavement is installed, but the structural integrity will quickly begin to fail. Without reconstruction, you should expect to need maintenance and repairs at a much higher frequency. Potholes, cracks, and other surface issues will begin to appear. This can be a serious concern for drivers and pedestrians. Roads, parking lots, and even driveways can become unsafe, causing damage to vehicles, tires, and posing a potential safety risk for pedestrians. These damages can be costly and add up over time. Frequent repairs will also add up, meaning you will eat through your expected maintenance budget very quickly. Investing in a professionally installed asphalt pavement saves you time and money in the long run and keeps the pavement safer for everyone.

Preventing Pavement Failure with Tolliver & Curl

Tolliver & Curl provides top-tier pavement services for Central Ohio. Our team works with clients across the city to ensure their pavements are installed properly the first time to increase longevity and durability. If you’re experiencing drainage issues with an existing pavement, reach out to learn more about our repair services. If we believe the pavement cannot adequately be repaired, we will offer a quote on a full reconstruction.