The purpose of a sealant reservoir (Figs. 3.1, 3.2, and 3.6) is to prevent water and
incompressibles from entering the joint cavity. The design criteria for the sealant
reservoir ensure that the sealant stays in place. The ability of the sealant to expand and
contract with the movement of the joint is a function of the material properties of the
sealant (defined by the manufacturer’s specifications) and the expected movement of
the joint. Joint movement can be calculated using the following relationship