Beam-to-Column Connections for Precast Concrete Moment-Resisting Frames.
Beam-to-Column Connections for Precast Concrete
Cheok, G. S.; Stone, W. C.; Stanton, J.; Seagren, D.
Precast Seismic Structural Systems, 4th Joint Technical
Coordinating Committee, Proceedings. May 16-17, 1994,
Tsukuba, Japan, 1-8 pp, 1994.
concretes; beams; columns; tests; construction;
structural systems; dynamic characteristics
Precast concrete frame construction is not used
extensively in seismic regions of the USA. The UBC
[ICBO, 1991] currently permits only certain specific
building systems to be used and a precast frame is not
one of them. The reason is that extensive research on
cast-in-place frames has led to the development of
reinforcement details that provide suitable ductility,
and these details are now prescribed in the UBC. Im
most cases, these details cannot be easily achieved in a
purely precast system. The result is that most precast
structures can be made to satisfy the UBC only under the
guise of an "undefined structural system" which must
"...be shown by technical and test data which establish
the dynamic characteristics and demonstrate the lateral
force resistance and energy absorption capacity to be
equivalent to systems listed in Table No. 23-O for
equivalent Rw values." This requirement makes approval
of a precast frame very difficult. In addition, another
UBC requirement calls for "reinforcement resisting
earthquake-induced" forces to conform to ASTM A 706 and
A 615 Grades 40 and 60 specifications which excludes
prestressing steel. Since the advantages of precasting
and prestressing are interlinked, this provision on
prestressing inhibits the use of precast concrete.