chapter 3 rigid pavement - DOT On-Line Publications - Department ...
chapter 3 rigid pavement - DOT On-Line Publications - Department ...
chapter 3 rigid pavement - DOT On-Line Publications - Department ...
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6. CONSTRUCTION JOINTS<br />
a. Transverse Construction Joints<br />
(1) Transverse construction joints should normally replace a<br />
planned contraction joint. However, they should not be<br />
skewed, as satisfactory concrete placement and consolidation<br />
are difficult to obtain. Transverse construction joints<br />
should be doweled as described in paragraph 4b(2) and<br />
butted, as opposed to keyed. Keyed transverse joints tend<br />
to spa11 and are not recommended.<br />
(2) It is recommended that transverse construction joints be<br />
sawed and sealed. The reservoir dimensions should be the<br />
same as those used for the transverse contraction joints.<br />
b. Lonaitudinal Construction Joints<br />
(1) The decision to use keyed longitudinal construction joints<br />
should be given careful consideration. The top of the slab<br />
above the keyway frequently fails in shear. For this<br />
reason, it is recommended that keyways not be used when the<br />
<strong>pavement</strong> thickness is less than 10 inches. In these cases,<br />
the tiebars should be designed to carry the load transfer.<br />
(2) When the <strong>pavement</strong> thickness is 10 inches or more, a k;y;y<br />
. may be used to provide the necessary load transfer.<br />
keyway is to be used, the recommended dimensions are shown<br />
in Figure 1. Keyways larger than the one shown may reduce<br />
the concrete shear strength at the joint and result in joint<br />
failures. The keyway should be located at mid-depth of the<br />
slab to ensure maximum strength. Tiebars are necessary when<br />
using keyways. Consideration should be given to deleting<br />
the keyway and increasing the size and/or number of tiebars. *<br />
The additional steel cost may be more than offset by the<br />
patential savings in initial labor and future maintenance<br />
costs.<br />
(3) Tiebars should not be placed within 15 inches of transverse<br />
joints. When using tiebars longer than 32 inches with<br />
skewed joints, tiebars should not be placed within 18 inches<br />
of the transverse joints.<br />
(4) It is essential that the tiebars be firmly anchored in the<br />
concrete. Tiebars should be either mechanically inserted<br />
into the plastic concrete or installed as a two-part<br />
threaded tiebar and splice coupler system. It is<br />
recommended that periodic pull-out tests be conducted to<br />
ensure the tiebars are securely anchored in the concrete.<br />
Attachment 2 describes a recommended testing procedure for<br />
tiebars.<br />
3.1.9
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