Civil Engineering Reference
In-Depth Information
with a range of - 45
C. The transducers are connected to data-logger
installed on site via shielded cables with a 22-gauge tinned copper conductors and
polyurethane jacket.
°
C to 100
°
Fig. 4.6
VW Displacement Transducer across Joint
Installation Procedure
:
To install the VW displacement transducers across the
joint, the underside of the concrete slab was drilled at two locations across the
joint to a depth of 56 mm (2.5 in), and a high-strength fast-setting non-shrink
epoxy (Hilti HY150) was placed in the cleaned holes. No. 5 reinforcing bars
fabricated with a threaded hole on the exposed side were then introduced in the
holes and held in place by means of wood wedges. The transducer was then
mounted on the anchors by means of ball joints connected to each end, and
screwed to the threaded part of the bars. Fig. 4.6 illustrates the VW displacement
transducer installed across the construction joint.
A different setup was used to install the VW displacement transducer parallel to
the joint (Fig. 4.7). A 152 mm (6 in) long equal-legs steel angle with 50.8 mm (2
in) legs and a thickness of 12.7 mm (0.5 in) was mounted across the joint by
means of 12.7 mm (0.5 in) diameter expansion bolts anchored to the underside of
the concrete slab on each side of the joint, and bolted to the horizontal leg of the
angle. The vertical leg of the angle was threaded on one side of the joint to receive
one end of the transducer. A no. 5 reinforcing bar is also placed at the same side of
the joint. The transducer is then mounted in a position by means of a ball point
screwed to the anchored rebar and by a direct screwed connection to the vertical
leg of the steel angle. As shown in Fig. 4.7.
