Summer is officially here and St. Louis is famous for its heat waves. The heat plays an important factor relating to pavement defects. We will briefly discuss thermal cracking and how these types of cracks originate in your pavement.
For the last 15 years or more St. Louis typically hits major heat waves and often a lack of moisture. This combination is harsh for our type of soil. Throughout most of the St. Louis area, our soil is comprised of a high content of clay. Clay soils are hard to stabilize especially when they are subjected to extreme moisture or extreme dryness. The last two summers we were in the major spells of drought. The combination of drought, heat, and clay soil makes for a favorable scenario to form cracks or other types of pavement defects. Some of you over the last several summers may have noticed large cracks that form in your yard. These cracks can be as wide as up to 3" in width. What forms these cracks? It's simple: Lack of moisture within clay soil and added high temperatures will cause shrinkage in the soil. This shrinkage causes thermal cracking. Imagine putting any sort of plant material out in the sun and keeping it from moisture. - What happens??? It shrivels up! The same thing happens to our soil. The clay is simply shriveling up due to lack of water. These same cracks you see in your yard are most likely the same types of cracks you get in your driveway, roads, and parking lots. Want to test this scenario? Take a thin piece of rod, wire, or coat hanger sized material about 3' long. Find some fresh, wide cracks in your lawn or driveway. See how far you can stick that rod down into the crack. You may be surprised to see that in many cases, over half of the road will be swallowed up by the crack.
Here at Creve Coeur Paving, we have many options for dealing with cracks:
- For surfaces already in good condition, we use hot rubberized crack filler to fill and protect cracks. This material is strong and flexible and can last up to 4 years per application.
- For asphalt surfaces in need of resurfacing or an overlay, we can install Petro-Tac crack barriers to prevent existing cracks from reflecting through new surfaces. This material is a woven fiberglass/rubberized membrane that is applied directly on the crack and prevents water penetration, and shifting from the crack from disturbing the surface.
- For brand new projects we can implement our Perma-Base rock system. Perma-Base is excellent for stabilizing clay soils. In most cases, Perma-Base will eliminate cracking in asphalt pavement.