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

h. The most common types of pavement joints, which are
defined by their function, are as follows:
(1)
(2)
(3)
(4)
. .
Transverse Contraction Joint - a sawed, formed, or
tooled groove in a Concrete slab that creates a
weakened vertical plane. It regulates the
location of the cracking caused by dimensional
changes in the slab, and is by far the most common
type of joint in concrete pavements.
Longitudinal Joint - a joint between two slabs
which allows slab warping without appreciable
separation or cracking of the slabs.
Construction Joint - a joint between slabs that
results when concrete is placed at different
times. This type of joint can be further broken
down into transverse and longitudinal joints.
Expansion Joint - a joint placed at a specific
location to allow the pavement to expand without
damaging adjacent structures or the pavement
itself.
4. W. The primary purpose of
transverse Contraction joints is to control the cracking
that results from the tensile and bending stresses in
concrete slabs caused by the cement hydration process,
traffic loadings, and the environment. Because these joints
are so numerous, their performance significantly impacts
pavement performance. A distressed joint typically exhibits
faulting and/or spalling. Poor joint performance frequently
leads to further distresses such as corner breaks, blow-ups,
and mid-panel cracks. Such cracks may themselves begin to
function as joints and develop similar distresses. The
performance of transverse contraction joints is related to
three major factors:
a. Joint S=ciw Joint spacing varies throughout the
country becauie of considerations of initial costs,
type of slab (reinforced or plain), type of load
transfer, and local conditions. Design considerations
should include: the effect of longitudinal slab
movement on sealant and load transfer performance; the
maximum slab length which will not develop transverse
cracks in a plain concrete pavement; the amount of.
cracking which can be tolerated in a jointed reinforced
concrete pavement; and the use of random joint
spacings.
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