Table of Contents
Advertisement
8
4.3 Alternative Suspension Method
Geokon strain gages may also be suspended by attaching two short pieces of steel rebar to the
existing rebar using nylon cable ties, and then securing the strain gage to the shorter pieces of
rebar with more cable ties, as shown in Figure 9. This method avoids the resonance problems
associated with using soft iron tire wires to suspend the gage as described in Section 4.2.
Figure 9 - Alternative Method for Attaching Model 4200/4200HT Strain Gages to Rebar
4.4 Using Precast Briquettes, Shotcrete, or Grouting
An alternate method to casting the units into the concrete mix directly is to precast the gages into
briquettes of the same mix as the mass concrete and then place the briquettes in the structure
prior to concrete placement. The briquettes should be constructed no more than three days prior
to installation, but no less than one day prior, and should be continuously cured with water while
awaiting placement in the mass concrete.
Geokon strain gages may also be used in shotcrete, as well as in drilled holes in rock or concrete
that are subsequently grouted. When used in shotcrete special care should be taken to protect the
lead wires, such as encasing them in conduit or heavy tubing. The gages may be placed by
packing the immediate area around the gage by hand and then proceeding with the shotcrete
operation.
Advertisement
Table of Contents
