Present By: Dan Zollinger, Texas A&M Transportation Institute
Over Dr. Shiraz Tayabji’s career several changes occurred in the design and construction technology associated with CRC pavement. The design technology evolved from the empiricism of the AASHTO era of pavement design which essentially mirrored thickness design for jointed concrete to a distinctive mechanistic approach that individualized the design with respect to the characteristics of CRC pavement. Construction trends evolved from allowing the development of the cracking pattern in a random fashion to actively inducing the cracking through surface notching and improved positioning of the reinforcement. These changes will ultimately impact the engineering approach to CRC pavement for many years to come.
Continuously reinforced concrete pavement (CRCP) contains continuous, longitudinal steel reinforcement without transverse joints, except where required for end-of-day header joints, at bridge approaches, and at transitions to other pavement structures. Continuous reinforcement is a strategy for managing the transverse cracking that occurs in all new concrete pavements. In new concrete pavements, volumetric changes caused by cement hydration, thermal effects, and external drying are restrained by the pavement base layer and longitudinal reinforcement causing tensile stresses to develop in the concrete. These stresses, referred to as restraint stresses, increase more rapidly than the strength of the concrete at early ages of the concrete pavement, so, at some point, full-depth transverse cracks form, dividing the pavement into short, individual slabs. In CRCP, the continuous reinforcement results in internal restraint and produces transverse cracks that are closely spaced with small crack widths that help to maximize the aggregate interlock between adjacent CRCP panels. This feature is different from jointed plain concrete pavements (JPCP), where the number and location of transverse cracks are typically managed by timely sawing. In CRCP, the shorter panel sizes and high load transfer between adjacent CRCP panels reduce the flexural (bending) stresses from traffic loads and temperature and moisture curling. A third type, jointed reinforced concrete pavement (JRCP), incorporates wire mesh reinforcement equaling about 0.2 percent of the cross-sectional area of the concrete; however, it is no longer widely used for highway pavements in the U.S. The basic features of these three concrete pavement types are shown in Figure 1.
Details
| Title | Continuously Reinforced Concrete Pavements |
| Duration | 20 Mins |
| Language | English |
| Format | MP4 |
| Size | 49 MB |
| Download Method | Direct Download |
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