Non-destructive testing for crack width and variability on continuously reinforced concrete pavements: Fid-Bau Portal

Non-destructive testing for crack width and variability on continuously reinforced concrete pavements

Kohler, E. / Roesler, J.

Previous research has shown that the major failure mode in continuously reinforced concrete pavements (CRCP) is the punchout, which is a distress associated with the loss of load transfer capacity across transverse cracks. Despite the fact that crack width is widely recognized as one of the most important factors in CRCP punchout development, little research has been focused on effectively quantifying this variable. This paper presents results of crack width determined by measuring the crack closing movement under the action of vertical loads. The CRCP crack width data is generated by using a rolling wheel load and alternatively with a falling weight deflectometer (FWD) measuring technique. Crack width was successfully determined using an FWD, which enables future use of this device and technique to determine field CRCP crack widths. Crack width distribution is difficult to initially assess on CRCP test sections since the zero-crack width temperature needs to be known and the average pavement temperature must be less than this value during the testing. The data gathered from this study consisted of crack width from 31 transverse cracks on a uniform section, measured at the surface, when pavement temperature was 9.5 deg C (average top and bottom) and the temperature differential was 0.5 deg C. In this case, the average width was 59 microns and the standard deviation was 11.6 microns. Based on the measured crack width data, a Weibull distribution of the crack width was proposed whose shape parameters were related to the minimum, maximum, mean, and standard deviation of the crack width data.