AbstractsEconomics

"Structurally, there are two types of joints used in concrete pavements: (a) the tied, or permanently-closed joint; and (b) the open or free type of joint. The permanently closed joint utilized tie-steel of some form to keep the joint from opening. Usually, this steel is in the form of short individual bars extending across the joint and bonded to both slabs (designated as "tie-bars") or in the form of distributed reinforcement. The remaining method of classification, that of refering [sic] to the joint purpose, gives the expansion joint, contraction joint, and warping joint. An expansion joint is, as the name implies, a joint which can close without any appreciable restraint when the adjoining slabs expand. In order for this type of joint to fulfill its intended purpose, the joint must be constructed as an open joint, with the space between joint faces filled with a compressible material, or the joint space must be covered to prevent the infiltration of imcompressible [sic] foreign material" – Introduction, p. 3-4.