UFC 4-150-07
19 June 2001
CPM-1: HAND PLACEMENT
Description: Troweling a mortar into shallow, relatively small areas requiring
patching.
Uses: Patching surface areas small enough for hand work and shallow cavities
not suitable for dry pack.
Materials and Curing: Take careful measures to minimize drying shrinkage by
selecting a material mix design with a maximum allowable shortage of 0.05
percent per ASTM C 157 modified and proper curing.
Preparation:
a. Remove all loose and unsound old concrete.
b. If reinforcing steel is exposed, ensure 25 mm (1 inch) clearance all
around and wire brush steel bar.
c. Thoroughly clean repair area immediately before applying bonding
coat.
Bonding:
Vigorously brush coat repair area with sand-cement slurry: 1
part Type
II cement; 1 part sand; and enough water or latex for a consistency of thick
cream.
Mortar Mix: The
proportions of
the mix depend on
the overall size and depth of
the repair, accessibility, and whether the repair is large enough to require coarse
aggregate. A typical cement-to-sand ratio is 1:2.5 to 1:3. The water-cement ratio
should be no greater than 0.40.
Placement:
a. If repair is in direct sun or wind, build shade/wind break and leave
in place during curing period.
b. Wet the surface of repair area for 24 hours. Do not leave any free
water.
c. Brush coat repair area surface with cement slurry.
d. Immediately trowel on mortar mixture; completely fill voids and
dense placement.
Curing: Use wet burlap for 7 days or use a curing compound.
7-8