Buffalo - Cyclic Tensile Tests of Single Joint

The objective of this test series is to investigate the behavior of the liner-strengthened joints subjected cyclic tensile loads under different internal water pressures: normal pipeline working pressure of 48 psi and lower pipeline working pressure of 16 psi.

Two sets of cyclic tensile tests were performed on the two joints of pipeline specimen SP2. For both the East Joint and the West Joint of pipeline specimen SP2, four repetition tests were performed in the first cycle with a peak target shake table displacement of 0.50 in. and three repetition tests were performed in the other cycles with increased peak target shake table displacements until the failure of the liner. Strain gages were used to indicate where the liner had debonded from the ductile iron pipe and axial force was recorded throughout each cycle.

Liner failure was observed close to the end of spigot in both joints and non-uniform discolorations were found, which indicate the debonding between liner and the ductile iron pipeline.