ABSTRACT
The benefits offered by the modern polyurethane-based alternative to the traditional asphaltic flexible plug expansion joint, and its introduction to the Japanese bridge construction and maintenance industry, are described. This type of joint, which uses high-strength polyurethane (PU) instead of asphaltic material, maintains all the advantages of the asphaltic plug joint but greatly improves durability and elasticity, in particular over a wide range of temperatures, while also offering further benefits such as improved quality control of installation. As a result, this joint type is likely to be increasingly widely used in the future in Japan, as in any other country where high demands are placed on the durability and performance of the closed-surface low-movement expansion joints used in short-span bridge superstructures.
