TM 5-822-7/AFM 88-6, Chap. 8
c. Sawing. The sawing of contraction joints in
although dowels were used in cold joint construction
RCCP has proven to be unnecessary in past projects.
at Fort Stewart. There, the dowels were driven into
Cracks were allowed to form naturally in all of the
the RCCP before final set, and the adjacent fresh
Canadian-built RCCP, and virtually no distress has
lane was carefully worked around the dowels by
been observed at the cracks. These pavements have
hand. Until an efficient method is developed to insert
endured over 7 years of very heavy loads and
and align dowels properly in RCCP, the use of dowels
numerous freeze-thaw cycles. Attempts to saw
should be limited.
joints at Fort Hood and Fort Lewis produced a ragged
e. Vertical joints in two-lift construction. In two-
edge along the saw cut where pieces of cement paste
lift construction, care should be taken to align the
cold transverse and longitudinal joints in the upper
and aggregate were kicked out by the saw blade.
Until a suitable method is developed for sawing
and lower lifts to form a uniform, vertical face
through the depth of the pavement along the joint. If
joints in RCCP, this method should not be used.
the edge of the upper lift is not even with the edge of
d. Load-transfer devices. The stiff consistency of
the lower lift, the lower lift should be cut back even
RCCP does not lend itself to application of load-
with the edge of the upper lift (see fig D-5).
transfer devices such as dowels or keyed joints,
D-12. Curing.
are used, they should be thoroughly wetted, placed
a. General. Because of the low water content used
on the RCCP so that the entire surface and exposed
in an RCCP mixture, a combination of moist curing
edges are covered, and kept continuously wet. After
and membrane curing is recommended to prevent
the initial moist curing period, the RCCP should be
drying and scaling of the RCCP surface. The pave-
cured until it is at least 7 days old by one of the
ment surface should be kept continuously moist
following methods: water-spray curing, burlap or
after final rolling for at least 24 hours by means of a
cotton mat covering, or membrane-forming curing
water spray truck, sprinkler (fog spray) system, or
material. The curing material may be a white-
wet burlap or cotton mat covering. If burlap mats
pigmented membrane curing compound or an
D-13
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