To evaluate the effectiveness of maintenance treatments for asphalt pavement, four types of treatments, including the hot in-place recycling (HIR), milling and resurfacing (M&F), thin HMA overlay (THO) and microsurfacing (MS), were analyzed. 8 highway segments, in total 491.74 km, in Jiangsu Province in China, were investigated and the data of rutting depth (RD) in their maintenance history was collected. Based on the data of RD, the effectiveness of four treatments was quantitatively compared by three indicators, namely, performance jump (PJ), deterioration rate reduction (DRR) and average deterioration reduction rate (ADRR). Moreover, the applicability of the proposed effectiveness analyses was assessed by laboratory rutting tests with field cylindrical samples. Results indicate that the HIR is the most effective treatment, followed by M&F and THO. While the MS is the least effective treatment, whose service life is only three or four years. The findings highlight the significance of the proper traffic opening time after maintenance to avoid the weakened rutting resistance caused by high-temperature mixtures, the effect of the RD before maintenance on maintenance decision-making, and the application of high-quality RAP in the timely maintenance activities. Therefore, the performance-based maintenance strategy should be establish to improve pavement performance and extend pavement service life. Further research on the pavement performance after RAP application is necessary.

Currently, a fundamental relation between cohesion and adhesion in cohesive soils has not been established. Yet, it is of great importance to get a better understanding of the relationship between cohesive and adhesive forces, because the large surfaces on dredging tools can generate a lot of resistance, meanwhile limiting the production for materials with increasing adhesion. Because the relationship is not exactly known, the adhesive strength of a clay is usually expressed as a fixed fraction of the cohesive strength, varying between 60% for hard clays and 100% for soft clays. Material tests of cohesive soil have been undertaken to detect the actual relation between the adhesion and cohesion of cohesive soil. The experimental results can directly help the implementation of the Delft sand, clay and rock cutting model, as a result the optimal cutting angle in dredging practice can be calculated. In this way, the designs of dredging tools are improved, which can help to increase the overall production rate in dredging operations. This paper gives detailed description of the experiment setup and results.