Concrete Waterproofing Glossary
Jacking Device
(1) the device used to stress the tendons for prestressed concrete;
(2) the device for raising a vertical slipform.
Jacking Force
in prestressed concrete, the temporary force exerted by the device that introduces tension into the tendons.
Jacking Stress
the maximum stress occurring in a prestressed tendon during stressing.
Jaw Crusher
a machine having two inclined jaws, one or both being actuated by a reciprocating motion so that the charge is repeatedly nipped between the jaws.
Jitterbug
a grate tamper for pushing coarse aggregate slightly below the surface of aslab to facilitate finishing. (See also tamper.)
Joint
(1) a physical separation in a concrete system, whether precast or cast- in-place, including cracks if intentionally made to occur at specified locations;
(2) the region where structural members intersect.
Joint Filler
compressible material used to fill a joint to prevent the infiltration ofdebris and provide support for sealants applied to the joint.
Joint Sealant
compressible material used to exclude water and solid foreign materials from joints.
Joint Spall
a spall adjacent to a joint.
Joint-sealing Compound
an impervious material used to fill joints in pavements or structures.
Jointed Detail
a connection where the bending stiffness differs from that of the members and requires special design to collect, transfer, and redistribute forces from one member to another through the connection.
Jointer (concrete)
a metal tool used to cut a joint in fresh concrete.
Jointing
the process of producing joints in a concrete slab.
Joist
a comparatively narrow beam used in closely spaced arrangements tosupport floor or roof slabs.