How Important Is It To Seal Cracks In An Asphalt Surface?

It is important to implement an asphalt maintenance plan as soon as new pavement is completed. It is impossible to construct a pavement that does not develop cracks after a certain amount of service time. In regions with regular freeze and thaw cycles, cracks may appear after each winter. Crack filling beginning once cracks develop will keep asphalt in the best possible condition. 

Why Crack Sealing is an Important Part of an Asphalt Maintenance Plan 

The main purpose of crack sealing in asphalt or concrete is to protect pavement from premature failure. Unsealed cracks allow water and debris to flow into the crack opening. Water will create a weakened base, sub-base and surface resulting in alligator cracking and load related failures. Debris can cause the edges of the cracks to push up due to expansion from thermal changes. All cracks, even the smallest ones, can rapidly turn into major problems. Crack sealing is the single most cost effective asphalt maintenance procedure. 

Typical Asphalt Maintenance Plan

• Annual Cleaning

• Once Yearly: Inspect asphalt surface and repair cracks 

Cracks that are ¼-inch wide or greater should be sealed once per year. Crack sealing helps prevent moisture infiltration from subgrade moisture, which is one of the leading causes of pavement failure. It also helps prevent the asphalt from heaving, cracking further, and forming potholes. Crack repair and sealing are cost-effective asphalt maintenance methods that prevent major damage and help extend the life of your pavement.

When cracks are sealed at the proper time, two to four years of pavement life can be expected before other treatments are required.

How Should Sealant Be Applied to Cracks in an Asphalt Surface?

When there are cracks in the asphalt, a pavement router is used to grind loose material or debris from the cracks in the asphalt and create a clean, dry reservoir so cracks can be evenly sealed with an elastic material that protects against moisture infiltration. Routing enlarges the cracks to a specified depth and width, allowing the sealant to expand and contract during thermal changes in the surface pavement. Routed cracks stay sealed three to four times longer than cracks that are not routed.

The cracks should then be cleaned with an asphalt heat-lance, which uses forced super heated air to drive any moisture from the cracks in the asphalt and allow a proper bond with the hot crack sealant. An herbicide is applied to cracks as needed, where vegetation is a concern.

The crack sealant has an asphalt cement base, and may be formulated with rubber, plasticizers, polymers and reinforcing fillers. The heated sealant is applied to the clean, dry crack using a pressurized wand to maintain proper temperatures and ensure good adhesion. The top of the sealant should be left about 1/8-inch to ¼-inch below the top of the crack.

To speak with an asphalt expert about your asphalt maintenance, to schedule a paving consultation or to request a bid, contact Basic Construction at (757) 249-3789.

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