Pub. 1 2018-2019 Issue 2

By Steven R. Ford, Maxwell Products, Inc. G round movement, thermal expansion/contraction cycles, and traffic load can cause pavement failure that we call cracking. No one can stop the ground from moving or the surface of the Earth from heating and cooling. And once you have traffic loads that exceed the pave- ment’s load-bearing capacity, well, it is what it is. Once you have cracked pavement, the only question that remains is what to do next? Pavement maintenance professionals know sealing cracks and joints is their first line of defense, but it doesn’t have to stop there. With modern material develop- ments, there is a secondary line of defense, allowing you to even repair the ones that get away. Crack Sealing Pavement cracking must be sealed to prevent further deteri- oration. Water that is allowed to penetrate below the surface of asphalt pavement cracking may erode the base and cause cupping or freeze in winter, which can cause ice wedging. Incompressible debris can also fall into the crack and damage the crack walls during thermal contraction and expansion cycles, widening a crack and allowing even greater water infil- tration and channeling. If left untreated, this continual cycle of deterioration can lead to voids and potholes, which, in turn, may lead to vehicle damage and accidents. So treating asphalt cracks with a sealant appropriate for Utah’s climate is of paramount importance to pavement preservation officials. Be sure to choose a sealant for spe- cific Utah conditions, because sealant requirements vary from Logan to Saint George and from Skull Valley to the Uintah Basin. Modern chemistry has advanced crack sealant in recent years. Plasticizers, specialized polymers, and additives have improved sealant performance and provided addi- tional benefits like tracking resistance and improved vis- cosity curves. In addition to climate considerations, be sure you select a sealant that matches your performance needs. The Ones That Got Away Even if your pavement maintenance procedures are quite stringent, eventually, some cracking will get away from you. Ground movement and water infiltration will cause wider and more extensive cracks, and then you find yourself in that awkward gap between crack sealing and repaving. At that point, crack sealing is largely ineffective and repav- ing can be prohibitively expensive for a mere widened crack, cupped crack, fatigue cracking (alligatored areas), or similar distress. CRACK SEALING AND BEYOND MAINTENANCE: 24