Sealants and joint fillers

The sealants and joint fillers should be impervious to water, should be capable of being compressed and recovered, should have good adhesion properties to concrete, should not soften or harden as temperature varies and should be age resistant. 

The sealants are usually modified bituminous materials applied hot or cold. The hot applied sealant materials should comply with the requirements of specifications such as CEN EN 14188-1 (2004) or ASTM D 6690 (2012). The cold applied sealants should comply with the requirements of specifications such as CEN EN 14188-2 (2004) or ASTM D5893 (2010). 

The quantity of joint sealant to be poured into the joint depends on the depth and width of the gap or groove to be filled. As a rule of thumb, for expansion joints, a depth-to-width ratio of 1 1 to 1 1.5 is used, and generally, the depth should always be lower than or equal to the width. To limit the amount and depth of sealant applied to the joint, a sealant backer material (compressible caulking material) conforming to ASTM D 5249 (2010) or other standards is used. 

Apart from the poured joint sealants, particularly for the expansion type of joints, there are also preformed joint seals that are placed after compressing them into the expansion joint. These materials are such that they are always compressed, even when there is a complete expansion of the joint. The preformed joint seals should comply with specifications such as CEN EN 14188-3 (2006), ASTM D 2628 (2011), ASTM 1752 (2013), AASHTO T 42 (2010), AASHTO M 33 (2012), AASHTO M 153 (2011) or AASHTO M 213 (2010). 

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