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BY JUNA YUSUF
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TIE BAR PLACEMENT
By Teacher Juna Yusuf
JUNA YUSUF
What is tie bars ? Deformed steel bars or deformed epoxy coated steel .
Function : Hold the faces of
abutting slabs in contact
Not designed to act as load
transfer devices.
JUNA YUSUF
Where?
at longitudinal joints – mid depth of slab
between an edge
joint
a curb or shoulder
Measurement : 12.5 mm (0.5 inches) in diameter
and between 0.6 and 1.0 m (24 & 40 inches long).
JUNA YUSUF
About tie bar …
Prevent lanes
from separation
& differential
deflections
Reduce transverse cracking
Machine-‐place:
Placed by hand;
Chairs;
Drilled & grouted
If tie bars inserted exactly at transverse bar location, there a higher chance of
hitting the transverse bars. A better practice to insert tie bars a few inches away
from transverse bar locations.
JUNA YUSUF
What is the difference between tie bars and
dowel bars in concrete carriageway? • Tie bars : deformed rebars or connectors used for holding
faces of rigid slabs in contact to maintain aggregate interlock. Tie bars not load transferring device. For instance, tie bars are used in longitudinal joints in concrete pavement.
• Dowel bars are smooth round bars mainly serve as load transfer device across concrete joints. Placed across transverse joints of concrete pavement to allow movement to take place. Movement purposely designed for longitudinal joints, dowel bars can be adopted.
JUNA YUSUF
Spacing of the transverse
reinforcing steel & spacing
of the tie bars match. Before paving ,Tie bars will be placed at
the paintmarks during paving.
Half tie bar length was embedded into concrete. The other half sticks
out, ready to be cast in the adjacent
concrete placement -‐ tie bars
manually inserted into the plastic
concrete during paving operation.
JUNA YUSUF
Tie bars also used in plain jointed concrete pavement to connect two
lanes, @ a lane & shoulder
tie bar mechanically inserted by paving machine into fresh concrete
ahead of the float or it held in
position by support devices.
CRCP, there is not an available mat of steel reinforcement that can be used to position and secure the tie
bars.
JUNA YUSUF