Pavement
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Rigid Pavement Types

An introduction to some key types of rigid pavements and their potential uses. It includes essential concepts for how these pavements respond to and transfer loads.

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Jointed Reinforced Concrete Pavement

Jointed reinforced concrete pavement (JRCP, see Figure 1) uses contraction joints and reinforcing steel to control cracking. Transverse joint spacing is longer than that for JPCP and typically ranges from about 7.6 m (25 ft.) to 15.2 m (50 ft.). Temperature and moisture stresses are expected to cause cracking between joints, hence reinforcing steel or … Read more »

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Reinforcing Steel

Reinforcing steel can also be used to provide load transfer. When reinforcing steel is used, transverse contraction joints are often omitted (as in CRCP). Therefore, since there are no joints, the PCC cracks on its own and the reinforcing steel provides load transfer across these cracks. Unlike dowel bars, reinforcing steel is bonded to the … Read more »

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Continuously Reinforced Concrete Pavement

Continuously reinforced concrete pavement (CRCP, see Figure 1) does not require any contraction joints. Transverse cracks are allowed to form but are held tightly together with continuous reinforcing steel. Research has shown that the maximum allowable design crack width is about 0.5 mm (0.02 inches) to protect against spalling and water penetration (CRSI, 1996[1]). Cracks … Read more »

Figure 3. Dowel bars in place at a construction joint- the green color is from the epoxy coating.

Dowel Bars

Dowel bars are short steel bars that provide a mechanical connection between slabs without restricting horizontal joint movement. They increase load transfer efficiency by allowing the leave slab to assume some of the load before the load is actually over it. This reduces joint deflection and stress in the approach and leave slabs. Dowel bars … Read more »

Figure 1. Tie Bars Along a Longitudinal Joint

Tie Bars

Tie bars are either deformed steel bars or connectors used to hold the faces of abutting slabs in contact (AASHTO, 1993[1]). 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 … Read more »

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Reclaimed Concrete Material Used as Coarse Aggregate

In general, adequate PCC pavement can and has been constructed using RCM as a coarse aggregate. Purpose Coarse aggregate in PCC, aggregate in HMA Materials RCM crushed to a predetermined size Mix Design Standard PCC mix design.  Most standards consider RCM coarse aggregate to be a conventional coarse aggregate and treat it as such.  If … Read more »

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Reclaimed Concrete Material Used as Base or Fill

RCM is most often used as aggregate in a base or subbase course.  Although it is generally of high enough quality to be used as base material, RCM can also be used for lesser applications like embankment or fill material. Since RCM is a crushed material, the angular aggregates will provide excellent stiffness and load … Read more »

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PCC Recycling

Reclaimed concrete material (RCM), sometimes referred to as recycled concrete pavement (RCP), is typically generated by rigid pavement rehabilitation or reconstruction. When crushed, RCM can be used in a variety of ways: As an aggregate in PCC and HMA. As a granular base course. As a fill or embankment material. Generally, recycling PCC involves breaking … Read more »

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Load Transfer

“Load transfer” is a term used to describe the transfer (or distribution) load across discontinuities such as joints or cracks (AASHTO, 1993[1]). When a wheel load is applied at a joint or crack, both the loaded slab and adjacent unloaded slab deflect. The amount the unloaded slab deflects is directly related to joint performance. If … Read more »

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Jointed Plain Concrete Pavement

Jointed plain concrete pavement (JPCP, Figure 1) uses contraction joints to control cracking and does not use any reinforcing steel. Transverse joint spacing is selected such that temperature and moisture stresses do not produce intermediate cracking between joints. This typically results in a spacing no longer than about 6.1 m (20 ft.). Dowel bars are … Read more »

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