Asphalt Paving and Sealcoat  Blog

Asphalt Cracking - repairable with sealant or fill

Cracks that form in the pavement surface can allow many harmful substances - including water, salts and engine oils - into the base and subgrade, effectively leading to the failure of the pavement surface. There are many types of cracking and many causes for these differing problems. In many cases, cracks develop because of the expansion or contraction of the base or subgrade or because of voids that form between the layers or courses of pavement. These cracks can form randomly or in the following specific forms. In all cases, if repaired while still within ¼" to ½", these cracks are easily repaired and maintained.

Transverse cracking
Transverse cracking, or cracks that occur across the pavement surface about perpendicular to the parking lot
center, are often caused by the asphalt expansion and contraction due to temperature changes and or this
movement due to asphalt aging. Initially, these cracks will be relatively equally spaced depending on traffic but
will eventually become more prevalent in the parking lot or roadway. In some cases, as these cracks become
more prevalent, block cracking forms where the Transverse cracks develop into squares throughout the
pavement. Also, these cracks may extend either entirely or partially across the pavement area or roadway.
Transverse cracks begin as "hairline" cracks - or cracks up to ¼" wide - but will widen to ½" or wider with age
and lack of proper repair. Because these cracks are allowing water into the pavement base and subgrade, lack of
proper repair or maintenance will lead to more cracks developing parallel to the original transverse cracking. If
not properly repaired, these transverse cracks will be appear with greater prevalence and the cracks will become
wider; eventually, the cracks will be so prevalent that entire areas will be broken or "alligatored" leading to a more serious, cutting and patching repair.

 

 

This crack has formed across the
entire walkway. Eventually, as
moisture and other substances seep in
to the base, more cracks will form and
lead to pavement failure. 

Longitudinal cracking
Longitudinal cracking, or cracks that form down the center of the pavement surface or
roadway, usually develop due to the deterioration of longitudinal joints formed by
separate passes of an asphalt paving machine. When the parking lot is constructed, the
paving machine must make separate passes which form two lanes of asphalt; joints
develop between these two lanes because this is usually the least dense areas of
pavement and is not properly compacted. These cracks are fundamentally the same as
Transverse cracks, despite their difference in orientation, and also allow water, salts,
engine oils and other harmful substances into the base and subgrade. These
substances lead to more cracks in the pavement and eventual pavement failure around
the original Longitudinal cracks. Usually Longitudinal cracks follow the same type of size
development as Transverse cracks: starting as hairline or about ¼" cracks then
developing to larger, more serious problems; eventually, without proper repair and
maintenance, Longitudinal cracks will become more prevalent and areas, leading to
cutting and patching necessity. Block cracks also form from Longitudinal cracks.

This crack has formed at the center of a parking lot's drive
lane, at the joint of the separate passes of a paving
machine. Smaller cracks have developed around the
original crack.