Influence of design and construction features on the response and performance of SPS-2 test sections

This research was conducted to study the influence of design and construction features on the performance and response of jointed plain concrete pavements. The data used in this study were drawn from the Long Term Pavement Performance (LTPP) SPS-2 experiment. Pavement sections with undrained, dense-graded aggregate bases and undrained lean concrete bases have so far performed more poorly than sections with drained permeable asphalt-treated bases. Sections with thinner PCC slabs and lane width of 12 ft showed higher transverse cracking and pumping. The occurrence of transverse cracking in the sections seems to be a direct consequence of problems encountered during construction. It is too early to comment about the occurrence of faulting because of insignificant magnitudes of faulting in the test sections. A "Performance Index" was developed to evaluate the pavement sections due to the various limitations in the database and inconsistencies in the data collection process. Several statistical methods were used to validate the results obtained from the engineering analysis. It was also found that the individual deflections should be used in conjunction with load transfer efficiency (LTE) and edge support factor to completely understand the performance of the joints. In addition to the design and construction features, the effect of temperature is also an important factor to be considered in assessing the loss of support and in joint performance evaluation.