In a wide spectrum of pavement rehabilitation techniques, the application of thin asphalt overlay on existing concrete pavements have shown its ability to restore the functional capacity of the pavement system as well as maintain structural capacity. Although, prior researches stated that it does not add to the structural capacity of the existing pavement, the insulation generated by the asphalt overlay can affect the behavior of the discontinuities in the continuously reinforced concrete pavement (CRCP) system by reducing the magnitude of its movement. The investigation of crack movement behaviors of the CRCP in Chungbu Expressway was conducted in 2-phases: without overlay and with overlay. Crackmeters were installed at selected crack locations and measurements were collected. In the second phase of the investigation, crackmeters were installed at the concrete layer of the CRCP before a 2-inch asphalt overlay was applied. Results have shown that the crack movements under a thin asphalt overlay have reduced by 80% which indicates an effective insulation of the CRCP.

PURPOSES: The purpose of this study is to investigate the relationship between the crack propagation depth through a slab and crack width movement in continuously reinforced concrete slab systems (CRCSs). METHODS : The crack width movements in continuously reinforced concrete pavement (CRCP) and continuously reinforced concrete railway track (CRCT) were measured in the field for different crack spacings. In addition, the crack width movements in both CRCP and CRCT were simulated using finite element models of CRCP and CRCT. The crack width movements, depending on the unit temperature change, were obtained from both the field tests and numerical analysis models.. RESULTS: The experimental analysis results show that the magnitudes of the crack width movements in CRCSs were related to not only the crack spacing, but also the crack propagation depth. In CRCP, the magnitudes of the crack width movements were more closely related to the crack propagation depths. In CRCT, the crack width movements were similar for different cracks since most were through cracks. If the numerical analysis was performed to predict the crack width movements by assuming that the crack propagates completely through the slab depth, the predicted crack width movements were similar to the actual ones in CRCT, but those may be overestimated in CRCP. CONCLUSIONS: The magnitudes of the crack width movements in CRCSs were mainly affected by the crack propagation depths through the slabs.