Intelligent compaction (IC) is a construction method relatively new to the USA that uses modern vibratory rollers equipped with a global positioning system (GPS) receiver, an in-situ measurement system, a feedback controland reporting system. Though used for decades in the rest of the world, IC technology is less mature for its application in the hot mix asphalt (HMA) compaction than its counter part for the soil and subbase compaction. This paper aims to evaluate the effectiveness of IC technology for the HMAcompaction through a FHWA/Transportation-Pooled-Fund (TPF) project in Minnesota. The HMA pavement surface temperatures, roller passes and the Sakaicompaction control value (CCV) were recorded in real-time during compaction. The in-situ moduli of subbase materials and densities of HMA were measured. Results show that the IC roller can effectively track the HMA surface temperatures, roller passes/coverage and CCVs. The trend of CCVs from the HMA compaction is consistent with CCVs of mapping the underlying subbaselayer, indicating the reflecting effect of the underneath layers. A premature HMA failure section coincided with the weak support areas identified by the subbase mapping. The CCVs from HMA compaction are shown to have a linear relationship with the back-calculated modulus of the subbase layer. Thus, it is recommended to examine IC measurements from all constructionlayers. However, there are no consistent relationships between CCVs and nuclear-gauge densities of HMA based on the current dataset. The above findings along with upcoming TPF demonstrations are expected to establish the basis for future IC quality control (QC) and quality assurance (QA) specifications.
Abstract