Mechanical properties of pavement concrete with nano-particles are experimentally studied and compared with that of plain pavement concrete. The test results indicate that the flexural, compressive and splitting tensile strengths of pavement concrete with nano-particles are all improved with different extent. Firstly, the mechanical properties of pavement concrete are enhanced with the increasing content of nano-particles, and the peak values are achieved at certain content. Subsequently, the mechanical properties of pavement concrete are reduced with the increasing content of nano-particles. The optimum amount of nano-TiO2 and nano-SiO2 added into pavement concrete are respectively 1.0% and 2.0%. There is a significant linear relationship between flexural and compressive strengths of pavement concrete with nano-particles.

Long-span bridge across the river in cold areas, is often impacted by the drift ice in spring, thus having some severe effects on the stability and vibration of the bridge structure. With a long-span prestressed concrete T-rigid frame bridge as studied object, based on the display analysis function of the LS-DYNA software, this paper represents the simulating process of the contact and collision between the drift-ice and T-rigid frame bridge pier, and the influence of various factors was analyzed, such as model boundary condition, contact types of river ice and pier, algorithm and element connection transition area. Thus the reasonable calculation model of the collision force caused by drift-ice to pier was determined. The result has important theoretical and practical value to ensure the safety of the bridge in cold area, as well as to reduce the project cost.