"Water, water everywhere," is the last thing you want to see with an asphalt or concrete surface. Rain and other water sources have the stealthy ability to seep into imperfections and erode a seemingly sturdy structure. Yet, taking care of the surface before the first raindrop falls is the best way to avoid future headaches.
Common Asphalt Issues Caused By Rain
Timely asphalt and/or concrete repair is the best defense against these common issues, whether caused by rain or another source.
Rain can erode away the asphalt sealcoat over time, especially if the asphalt is on a sloped or slanted surface. Erosion is even more pronounced for surfaces not protected by a sealcoat. Any type of moisture reduces the bond between the binder and aggregate, known as stripping. As the bond weakens, the aggregate and subbase materials wash away and can enter nearby drains and waterways. The extent of erosion and subsequent asphalt repair hinges on many factors, such as weather conditions when the asphalt is poured, characteristics of the aggregate and binder materials, and overall climate.
Loss Of Skid Resistance
Bleeding is the term used to describe the film of asphalt binder which seeps to the surface during hot weather. In dry weather, the surface has a glass-like reflection and is sticky. When it rains, the bleeding surface loses skid resistance, creating a safety hazard for pedestrians and traffic.
The reason why it can appear as though asphalt and concrete cracks grow after rainfall is because they do. Thermal expansion occurs when the volume of water increases as the temperature also increases. Though summer is when most expansion occurs, once a crack has begun, any water that enters begins to break down the binder cohesion, also causing potholes and raveling.
The sublayers — base or subbase and subgrade — provide support for the surface layer. Most are made from granular materials, such as crushed stone, sand-gravels, and sand. Although these materials are compacted during installation, they can shift and soften when exposed to rain. If the sublayers destabilize, the surface is prone to shifting which may lead to cracks, potholes, and other damage.
Preventing Water Damage To Your Asphalt
Pavemax, a paving company in Florida, uses a variety of industry-leading methods and techniques to prevent water damage to any asphalt surface, including proper drainage, porous pavement, and regular maintenance.
Generally, accounting for proper drainage is part of the installation process but it can be adjusted after the surface is in place. Drainage allows rainfall to flow toward grassy areas or other bodies of water through the use of curbing and slopes. Proper drainage is important for any asphalt or concrete structure but more so for parking lots and roadways due to the long-term effect of ponding.
This is one area that can greatly counter how rain affects any asphalt or concrete surface. Periodically check the surface for cracks, divots, raveling, slippage, and other imperfections. Repairing any asphalt damage — even small cracks — as it appears decreases the opportunities rain has to enter the pavement. Also, applying a new layer of sealcoat every 3 years to 5 years helps prevent water damage.
This type of pavement is a growing solution to potential water damage. Porous pavement mixes less finely ground filler with the aggregate, creating a permeable yet structurally sound structure. Rather than running off the surface, rainfall filters into the ground, reducing soil erosion and heavy runoff situations which can contribute to flooding.