Steel
fiber reinforced polymer (SFRP) strips comprised of multiple high-strength
wires have been introduced into
the repertoire of the structural engineer in
recent years. The deleterious effects of fatigue
loading on FRP-to-concrete
bond have been identified in previous studies by the author; therefore the
effect of fatigue loading on the bond behavior of SFRP is investigated. Four
large-scale beam
specimens (4.9 m long) having externally bonded SFRP retrofits
are tested. These specimens are paired with unretrofit and CFRP-retrofit
companion specimens allowing a number of direct comparisons to be made. Of the
SFRP specimens, one is tested in monotonic loading to failure while the
remaining three are tested at various fatigue load levels ranging from service
load level to an extreme load level. Service load fatigue is cycled for two
million cycles and the specimen is then tested monotonically to failure to assess
the effects of fatigue on the ultimate performance of the beam. Extreme loading
is selected to result in fatigue-induced failure of the internal reinforcing
steel.