The degradation characteristics of polyurethane (PU) elastomer sliding against stainless steel were investigated using a pin-on-plate reciprocating tribo-tester in terms of the decrease in height of the specimen.
To fully monitor the strain history of the sandstone cylinder in uniaxial compression, six circumferential FBG sensors, four lateral FBG sensors, linear variable differential transformers (LVDT) built-in machine have been utilized for spatially monitoring small radial and axial strains along the height of the specimen, respectively.
The height of the specimen was kept 85 mm.
Table 3 shows the initial height of the specimen before deformation in comparison to the final height.
According to ISO-834, failure is determined when the axial deformation of the compression member reaches h/100 mm or the rate of deformation reaches 3 h/1000 mm/min within 2 h of fire, where h denotes the initial height of the specimen before the fire.
Figure 2 illustrates the ultimate drift capacity (the ultimate displacement capacity divided by the height of the specimen, δ u /h w ) for each failure mode except for the sliding failure mode, where the tests were interrupted before reaching the ultimate displacement capacity of the specimens.
Then, during the mechanical push-out test, we observed that the size of some of the bone graft extender granules was close to the full height of the specimen block.
In this case, even if the outside diameter of specimen remains the same, a variation in the position of the axis of the steel pulling bars allows the effective height (size) of the specimens to be varied.
The transverse strain was determined by an unbonded extensometer, with an accuracy of 0.5 μm, that measured changes in diameter at the mid-height of the specimen.
Two measurement methods, involving the use of linear variable differential transformers (LVDTs) either along the full- or mid-height region of the specimens, have been extensively used to measure the axial strains of FRP-confined concretes.
