What is tie bars in rigid pavement?
Tie bars are deformed rebars or connectors used for holding faces of rigid slabs in contact to maintain aggregate interlock. Tie bars are not load transferring device. For instance, tie bars are used in longitudinal joints in concrete pavement.
What are the uses of tie bars in cement concrete pavements?
Tie bars are used at longitudinal construction joints (LCJs) in portland cement concrete (PCC) pavement primarily to keep lanes from separating. As more lanes are tied together because of ever-increasing traffic volume, concerns about the potential for longitudinal cracking have led to the use of dowel bars at LCJs.
What is the purpose of dowel bars?
The primary advantage of dowel bars is to transfer load without restricting horizontal joint movements due to temperature and moisture expansion and contraction in the concrete slabs. Also, dowel bars play a role to maintain the vertical and horizontal alignment of slabs.
What is meant by tie bars?
1 : a bar used as a tie rod. 2 : a rod between two railway switch rails to hold them to gage.
What is tie bar in Railway?
Rail gauge rod, also named gauge tie rod or gauge tie bar, is a member bar which is specially designed to joint two steel rails at the rail bottom to protect the rails from tilting and keep the rails in certain rail gauge.
What is tie bar spacing?
Typically, tie bars are about 12.5 mm (0.5 inches) in diameter and between 0.6 and 1.0 m (24 and 40 inches long).
What is a tie bar in construction?
Tie bars are deformed, epoxy coated steel bars, typically placed mid‐depth across longitudinal joints or between an edge joint and a curb or shoulder. They are designed to prevent lane separation and differential deflection and reduces transverse cracks by holding the faces of abutting slabs in contact.
In which joint dowel bars are provided?
These locations are called contraction joints. Dowel bars are provided as load transfer devices across transverse joints and they tend to keep the two pavement slabs at same right.
What is a tie in in construction?
1. tie-in – a fastener that serves to join or connect; “the walls are held together with metal links placed in the wet mortar during construction”
What are tie bars used for in construction?
Tie bars used for holding faces of rigid slabs in contact to keep aggregate interlock. They are also used in plain jointed concrete pavement to connect two lanes. They are used to reduce transverse cracking.
What are the effects of tie bars on pavement?
Effect of tie bars on pavement responses 2nd International Conference on Best November 2, 2011 Practices for Concrete Pavements Aggregate No tie bars interlocking High stresses High deflections Pavement distresses Tie bars Low stresses Good joint Low deflections performance
Where do tie bars go on a paving slab?
They are placed at mid-depth slab and bent back till the adjacent lane is prepared to be paved. When slipform pavers are used, tie bars are inserted on the slab edges that would become longitudinal joints.
Can a tie bar be used as a load transfer device?
Although they may provide some minimal amount of load transfer, they are not designed to act as load transfer devices and should not be used as such (AASHTO, 1993 [1] ). Tie bars are typically used at longitudinal joints (see Figure 1) or between an edge joint and a curb or shoulder.
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