15 March 2001
slab surface. A joint sealant reservoir must be provided at the top of the slab above the shear
device (Figure 10.5.).
10.5. Patching Material. Polymer concretes and high early-strength PCC have been used in
most installations to date. The patch material used with load-transfer devices is the most critical
factor in performance, particularly with shear devices. Sufficient bond must be established
between the device and the patching material as well as between the existing concrete and the
For this reason, a thorough laboratory evaluation must be made of any patch material utilized for
the load-transfer devices. Prime factors which must be evaluated are: working time, rapid
early-strength gain, and shrinkage.
10.6. Placing. After the patch area has been properly cleaned,
a bonding agent should
applied (Figure 10.6.). The type of bonding agent will depend on the bond development
requirements for opening to traffic and type of patching material used. The manufacturer's
recommendations should be followed with all patching materials. Bonding agents should be
those recommended by the manufacturer for the placement conditions. The patch material
should be placed and consolidated to eliminate essentially all voids at the interface of the patch
and the existing concrete and at the load-transfer device and the patch.