Joint and Crack Resealing
Performed alone, joint resealing is a maintenance activity. However, in conjunction with techniques such as patching or surface grinding, joint resealing becomes a necessary part of CPR. It is usually the last step and is done to protect the newly rehabilitated pavement from excessive moisture.
The main purpose of sealing concrete pavement joints is to minimize the passage of surface water through joints to the subbase layers and the lodging of incompressible materials, such as pebbles and stones, along the joint faces . Resealing is necessary whenever the condition of an existing sealant does not meet these purposes, either because the sealant is missing or deteriorated.
A typical hot-pour sealant provides an average of 3 to 5 years of life after proper installation. Some low-modulus or PVC coal-tars can perform well past 8 years. Silicone sealants have performed well for periods exceeding 8 to 10 years on roadways. This type of performance hinges on joint preparation and installation. Of extreme importance is that the joint be clean and dry. Compression seals provide service for periods often exceeding 15 years and sometimes 20 years.
Some cracks will also require sealing to prevent the infiltration of moisture and incompressible materials. The need to seal a particular crack will depend upon the crack's condition and orientation. Narrow, hairline cracks that remain tight usually do not require sealing, but wide cracks that function like joints do require sealing. These cracks usually cycle open and closed with temperature changes in the same manner as transverse joints.
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