15 March 2001
SPALL REPAIR EQUIPMENT
14.1. Description. Much of the equipment necessary for spall repair has been previously
described under "Crack Preparation." However, additional equipment such as concrete saws,
jackhammers, mixers, small spud vibrators, tampers, and hand tools may also be necessary.
14.2. Concrete Saws. A conventional concrete saw is similiar to a random crack saw but
generally is less maneuverable and has a larger blade (Figure 14.1.). Concrete saws are
employed extensively for refacing joints for joint sealing projects but are often used for large
patching operations or full-depth repair. Small blades of 6 to 10 inches (170 to 250 millimeters)
should be used to minimize the size of the runout kerfs when sawing out the spall area. Larger
blades may be necessary for refacing joints or cracks. Small patches can be sawed with a
random crack or a hand-held saw.
14.3. Jackhammers. The jackhammer needed for large patching operations where full-depth
repairs are needed may be a 30-pound (13.6-kilogram) model (Figure 14.2.); for smaller jobs, a
10- to 15-pound (4.6- to 6.8-kilogram) model is sufficient. The jackhammer must be equipped
with a chipping hammer and worked at an angle of between 45 and 90 degrees relative to the
pavement surface. Special care must be taken not to damage the layer of concrete under the
spall repair area or cause microcracking around the crack.
14.4. Mixers. Drum or mortar mixers are usually employed for most patching operations.
Buckets may be used with a hand-held, electric drill-powered (or pneumatic), paddle-wheel mixer
for smaller operations.
14.5. Hand Tools. Hand tools such as shovels, trowels, tampers, and screeds must be