Improving Performance and Cost Effectiveness of CRCP Design Features: Terminal Joints, Construction Joints, Stabilized Subbase Erosion Resistance, and Mix Design
SUMMARY OF PROBLEM: Continuously reinforced concrete pavements (CRCP) have the highest initial cost, but several aspects of pavement design and construction could be revised to reduce the cost while still providing the benefits of low maintenance costs during service life. The areas for which study is required are terminal joints, construction joints, erodibility of the stabilized subbase, and use of lightweight aggregate.
- Terminal or transition joints in CRCP (e.g., wide flange beams or lugs) are expensive to construct, can result in high maintenance costs, and in some cases have been shown to be functionally ineffective.
- Other types of joints, such as transverse/longitudinal construction joints, may be located or reinforced in a less than optimal way, resulting in increased early-life maintenance.
- CRCP performance is directly impacted by the uniformity and erodibility of the stabilized subbase layer. With the increased use of recycled materials [reclaimed asphalt pavement (RAP) or crushed concrete] in the support layer and overlays, the erosion resistance of the stabilized subbase layer must be characterized under repeated loading in the presence of moisture.
- Lightweight aggregate has been shown to help with internal cure of concrete slabs by aiding with moisture absorption during hydration. This improved cure can potentially increase mixture strength, which could reduce thickness and initial construction cost.
CRCP provides a superior ride and low long-term maintenance, but improper terminal joint and transverse/longitudinal construction joint design, potential erosion of stabilized subbase, and less tha optimal mix design can result in recurring maintenance and premature failures (punch-outs or spalling). The benefit of CRCP in a life-cycle cost analysis assessment should be more apparent with these proposed improvements.