The applications of steel slag powder and steel slag aggregate in ultra‐high performance concrete (UHPC) were investigated by determining the fluidity, nonevaporable water content, and pore structure of paste and the compressive strength of concrete and by observing the morphologies of hardened paste and the concrete fracture surface. The results show that the fluidity of the paste containing steel slag is higher. The nonevaporable water content of the hardened paste containing steel slag powder is close to that of the control sample at late ages. Both steel slag powder and steel slag aggregate react and connect tightly to gels and hardened paste, respectively. When the cement replacement ratio is no more than 10%, the proportion of pores larger than 50 nm in the hardened paste containing steel slag powder is close to that of the control sample, and the UHPC containing steel slag powder can display satisfactory compressive strengths. The UHPC containing steel slag aggregate demonstrates higher compressive strengths.

In recent years, recycled or reclaimed asphalt pavement (RAP) has been used increasingly due to its advantages in building sustainable pavement infrastructure. In the meantime, concerns have been raised regarding the performance of mixtures involving RAP. One of the major concerns comes from the material variability because it is believed to possibly result in poor pavement performance, particularly for mixtures with high RAP content. To address this issue, this study is conducted along two steps hierarchically. First, RAP samples were collected from four field stockpiles. RAP material variability was established based on laboratory testing. Second, a factorial design was carried out for designing mixtures with varying RAP contents ranging from low (10%) and medium (25%) to high (40%). In particular, different blending conditions between RAP and virgin binders, including zero, partial, and full blending, were considered. The Mechanistic–Empirical Pavement Design Guide was used to predict pavement performance including distresses and ride quality for each design scenario. The relationships (1) between the RAP content and performance variability and (2) among the variabilities of different performances due to RAP material variability are finally revealed.

Based on laboratory tests, the objective of this study is to assess long-term road performance and to predict deicing longevity of self-ice-melting asphalt pavements containing salt-storage materials. Dry–wet cycles and freeze–thaw cycles were used to treat the specimens at different durations. The long-term road performance of self-ice-melting asphalt mixtures was evaluated by freeze–thaw splitting tests, high-temperature rutting tests, and low-temperature beam bending tests. In addition, the influences of coefficients of void ratio, temperature, vehicle load, crack, and Mafilon (MFL) content on salt precipitation were quantified by conductivity tests, and single consumption of snow and ice melt was quantified by total dissolved solids (TDS) tests. The results show that the long-term water stability, long-term high-temperature stability, and long-term low-temperature crack resistance of self-ice-melting asphalt pavements tended to decrease as the number of dry–wet cycles and freeze–thaw cycles increased. Freeze–thaw cycles exerted deeper influences on the deterioration of road performance than dry–wet cycles, especially on water stability. With increased void ratio and temperature, salt precipitation was accelerated by 1.1 times and 1.5~1.8 times, respectively. Under vehicle loads and cracks, salt precipitation was accelerated by 1.5 times and 1.65 times, respectively. With decreased MFL content, salt precipitation slowed down by 0.54 times. Finally, based on the proportion of each factor relative to the whole life cycle of the pavement, a dicing longevity prediction model was established considering the above factors.