TM 5-822-5/AFM 88-7, Chap. 1
a. Header. The header may be set on either side
dinal expansion joints because differential expansion
and contraction parallel with the joints may develop
of the transition slab with the transverse construc-
undesirable localized strains and cause failure of the
tion joint doweled, as required. The dowel size and
concrete, especially near the corners of slabs at
location in the transverse construction joint should
transverse joints. Expansion joints are not required
be commensurate with the thickness of the pave-
between two adjoining pavements where paving
ment at the header.
b. Transition between different joints. When
lanes of the two pavements are parallel.
(b) Transverse expansion joints within
there is a transition between a doweled longitudinal
pavements will be the doweled type (see fig 15-5).
construction joint and a keyed longitudinal
There may be instances when it will be desirable to
construction joint, the longitudinal construction
allow some slippage in the transverse joints such as
joint in the transition slab may be either keyed or
at the angular intersection of pavements to prevent
doweled. The size and location of the dowels or
the expansion of one pavement from distorting the
keys in the transition slabs should be the same as
other. Then, the design of the transverse expansion
those in the pavement with the doweled or keyed
joints will be similar to the thickened-edge slip
joint, respectively.
c. Transition between two keyed joints. When
joints (see para 15-6). When a thickened-edge slip
joint is used at a free edge not perpendicular to a
there is a transition between two keyed joints with
paving lane, a transverse expansion joint will be
different dimensions, the size and location of the
provided 75 to 100 feet back from the free edge.
key in the transition slab should be based on the
thickness of the thinner pavement.
15-3. Dowels.
15-5. Joint Sealing.
The important functions of dowels or any other
load-transfer device in concrete pavements are to
All joints will be sealed to prevent infiltration of
help maintain the alignment of adjoining slabs and
surface water and solid substances. Details of the
to transfer some stresses from loads to the adjacent
joint sealant are shown in figure 15-7. A jet-fuel
slab, thereby limiting or reducing stresses in the
resistant (JFR) sealant, either poured or preformed,
loaded slab. Different sizes of dowels will be
will be used in the joints of hardstands, washracks,
specified for different thicknesses of pavements (see
and other paved areas where fuel or other lubricants
table 15-2). When extra strength pipe is used for
may be spilled during the operation, parking,
dowels, the pipe will be filled with either a stiff
maintenance, and servicing of vehicles. Sealants that
mixture of sand-asphalt or portland cement mortar
are not fuel resistant will be used in joints of all
or the ends of the pipe will be plugged. If the ends
other pavements. Poured JFR sealants will conform
of the pipe are plugged, the plug must fit inside the
to Federal Specifications SS-S-200E and SS-S-
pipe and be cut off flush with the end of the pipe so
1614A, and poured non-JFR sealants will conform
that there will be no protruding material to bond
to Federal Specification 55-S-1401C. Use of SS-S-
with the concrete and prevent free movement of the
1401C requires MACOM approval for use on Air
dowel. Figures 15-1 and 13-1 show the dowel
Force Projects. Cold poured non-JFR sealants will
placement. All dowels will be straight, smooth, and
conform to CRD-C 527. Preformed sealants will
free from burrs at the ends. One end of the dowel
conform to ASTM D 2628 and tested according to
will be painted and oiled to prevent bonding with
the procedures in appendix C for jet-fuel resistance.
the concrete. Dowels used at expansion joints will
Lubricant for preformed sealants will conform to
be capped at one end, in addition to painting and
ASTM D 2835. Preformed sealants must always be
oiling, to permit further penetration of the dowels
compressed 45 to 85 percent of their original width.
into the concrete when the joints close.
The selection of pour-able or preformed sealant
should be based upon economics. Compression-
type preformed sealants are recommended when the
15-4. Special Provisions for Slipform Paving.
joint spacings exceed 25 feet and are required when
Provisions must be made for slipform pavers when
joint spacings exceed 50 feet.
there is a change in longitudinal joint configuration.
The thickness may be varied without stopping the
15-6. Special Joints and Junctures.
paving train, but the joint configuration cannot be
varied without modifying the side forms, which will
Situations will develop where special joints or
normally require stopping the paver and installing a
variations of the more standard type joints will be
header. The following requirements shall apply at a
needed to accommodate the movements that will
pavement transition area.
occur and to provide a satisfactory operational sur-
15-17
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