chapter 3 rigid pavement - DOT On-Line Publications - Department ...

.M~&$iU~eTle~t!S and eStZbliSkfXl tc3ta Ol‘i ?ilCr- h:L’T~‘iY!& ;iiid CJrling Of PCC
pavementr and the effect of extended PC:C ~t~wrct~:ni sia wth IZ ft (3.7 m)
channeIized traffic lanes is limited. “Warping iea- 6’~~ slabs unsupported for dis:ar.ces
of as mu& as 4 to 5 ft (1.2 to 1.5 37) iit Slab CQxi@:‘F; tld 2 to 3 ft (0.6 to 0.9 m) at siaj
edges.““” The loss of support along the slab edges and the compressive forces of the
concrete itself are two adverse effects of warping. Curling refers to the concrete slab
behavior due to the differing temperatures in the slab depth. Slabs curl upward
(corner support lost) during the night because the temperatures are cooler on the top
surface than on the bottom of the slab. Conversely, slabs cur1 downward (corners
downward) during the day due to the warmer temperatures on the top surface or’ the
slab compared to the bottom. There is not enough information available to see any
differences in warping and curling with the use of extended KC pavement slabs.
Water infiltration underneath existing pavements is being emphasized as a
major factor in the deterioration of some pavement structures. The use of extended
pavement slabs would mean less traffic directly on the longitudinal shoulder joint
(either ITC or AC shoulder). The required maintenanee of the joint seal should be
lower and the seal achieved during construction would function as an effective joint
for a longer period of time because of the fewer applied loads. With a better
performing joint, there should be less water infiltrating through the longitudinal edge
joint to the underlying base material and less potential deflections due to the lateral
wheel load location.
Photo 4 - Ulustration of PCC pavement/shoulder joint deterioration. Note the
pavement edge line location (12-foot lanes).