An evaluation of the built-in temperature difference input parameter in the jointed plain concrete pavement cracking model of the Mechanistic-Empirical Pavement Design Guide

• Published in: The international journal of pavement engineering 2011-06, Vol.12 (3), p.215-228
• Main Authors: Vandenbossche, J.M., Mu, F., Gutierrez, J.J., Sherwood, James
• Format: Article
• Language: English
• Subjects: built-in temperature difference; Calibration; Civil engineering; Concrete pavements; Concretes; Crack propagation; cracking; Fracture mechanics; jointed plain concrete pavement; Mathematical models; MEPDG; Optimization; Pavement design; Pavements; Slabs; Studies; Temperature effects; traffic distribution
• ISSN: 1029-8436; 1477-268X
• DOI: 10.1080/10298436.2010.489113

This paper evaluates the implementation of the built-in temperature difference input parameter in the Mechanistic-Empirical Pavement Design Guide (MEPDG) for the design of jointed plain concrete pavements (JPCPs). The pavement distress, in terms of transverse cracking, is expected to be minimised when the transient temperature difference is equal in magnitude to the built-in temperature difference but of the opposite sign. However, this study shows that a built-in temperature difference of − 6.5°C minimises the cracking prediction for JPCPs. This optimum value of − 6.5°C coincides with the default value in the MEPDG of − 5.5°C, which was established through the nationwide calibration. The cause of this phenomenon is further investigated by taking into account the traffic loading time, slab thickness, joint spacing and reversible shrinkage, but none of these factors are able to explain this anomaly. The results from this study indicate that the built-in gradient should not be an input but is merely a calibration constant. A comparison between predictions using the measured and default built-in temperature difference again supports that it is better characterised as a calibration constant.