Portland Cement Concrete Pavement Joint Sealant Practices and Performance (2021) / Chapter Skim
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6 Literature Review This chapter documents the results of the literature review conducted before the distribution of the questionnaire. The topics discussed in this chapter include the following: • Joints in concrete pavements • Early use of sealant in PCC pavements • Current sealant material types • Current sealant practice • Joint and reservoir design (including sealant movement and geometry, surface configuration, and material selection)
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Literature Review 7 bituminous materials to fill the joints. Bituminous materials were relatively low-cost and easy to place.
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8 Portland Cement Concrete Pavement Joint Sealant Practices and Performance Preformed (compressive) sealant -- Manufacturers introduced preformed compression sealants in the early 1960s.
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Literature Review 9 helps to establish a suitable sealant shape factor (SF)
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10 Portland Cement Concrete Pavement Joint Sealant Practices and Performance about 20 percent tensile strain of their initial width. Silicones and some other low-modulus materials can theoretically undergo up to 100 percent strain.
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Literature Review 11 at the time was on fillet joints. Moreover, in this study, cyclic testing did not produce definitive results because of the limited range of strains tested.
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12 Portland Cement Concrete Pavement Joint Sealant Practices and Performance because experience suggests that tire contact with the sealant keeps it pliable and reduces joint noise. For silicone sealants, SF design inherently includes recessing the sealant below the pavement surface by 1⁄4 to 3⁄8 in.
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Literature Review 13 Material Selection When planning a joint sealing project, one of the primary design activities is the selection of appropriate sealant material. Material selection is dependent on a number of factors, typically including the following: • Climate conditions (at the time of installation and during the life of the sealant)
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14 Portland Cement Concrete Pavement Joint Sealant Practices and Performance and Jung 2013)
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Literature Review 15 Category Material Type Specification(s) Description Liquid, Hot-Applied Sealants (Thermoplastic)
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16 Portland Cement Concrete Pavement Joint Sealant Practices and Performance foam or extruded polyolefin foam rod is used for cold-applied sealants. The diameter of the rod should be at least 25 percent larger than the width of the joint.
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Literature Review 17 • The backer rod used with hot-pour sealants should tolerate the specified application temperature of the sealant.
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18 Portland Cement Concrete Pavement Joint Sealant Practices and Performance • Step 3. Backer rod installation -- The backer rod should be compatible with the sealant and sized about 25 percent to 50 percent greater than the reservoir width.
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Literature Review 19 inspection. General quality control tests for joint reservoir moisture conditions are currently in development (ACPA 2018)
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20 Portland Cement Concrete Pavement Joint Sealant Practices and Performance opening the pavement to traffic. Manufacturer recommendations for application, depth of recessed configuration, and curing time should be followed.
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Literature Review 21 between 20 percent and 50 percent of its width (ACPA 2018)
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22 Portland Cement Concrete Pavement Joint Sealant Practices and Performance • The benefits and cost-effectiveness of joint sealing have been debated since the 1970s. The need for concrete paving joint sealing is likely project-specific and related to the type of pavement, pavement section (including the drainage, erodibility, and frost resistance of the foundation materials)
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Literature Review 23 Longitudinal cracking, corner breaks, and freeze-thaw damage are other examples of distress related to moisture trapped in pavement at the joints (Qi, Weiss, and Olek 2003)
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24 Portland Cement Concrete Pavement Joint Sealant Practices and Performance Silicone-based sealant materials can have good durability and bonding characteristics if properly installed. This type of sealant material may also be simpler to install than asphalt sealants.
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Literature Review 25 evaluate the effects of different factors on sealant failure. As stated earlier, three different types of sealants are primarily used: asphalt-based sealants, silicone-based sealants, and preformed compression sealants.
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26 Portland Cement Concrete Pavement Joint Sealant Practices and Performance The results of these two studies show that appropriate installation can yield sealants with a service life of more than 20 years. Previously, little factual evidence existed to indicate the type of serviceability possibilities, but these findings confirm and document that sealants can last much longer than present service-level expectations (Ioannides, Long, and Minkarah 2004; Lynch et al.
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Literature Review 27 Selecting Materials and Equipment for Resealing The selection of sealant for resealing is similar to the selection of a sealant for new construction, except that preformed sealants are typically not used in resealing operations. Older pavement in good condition can present some issues for preformed seals, most notably in terms of variable and nonuniform joint widths and the presence of joint spalling.
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28 Portland Cement Concrete Pavement Joint Sealant Practices and Performance which should be considered as well when comparing sealed and unsealed pavement maintenance costs. Construction Considerations The resealing process is similar to the new sealing process described earlier, with two further steps.
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Literature Review 29 Alternative Methods Saw and sealing operations have been estimated to be between 2 percent and 7 percent of initial construction costs (Hall et al.
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