Experimental Study On Energy Dissipation Properties Of Rubberized Concrete And Its Application In Anti-collision Of Bridge Piers

With the development of the traffic infrastructure construction in our country, there is a sharp increase in the number of bridge structures. The vehicle-bridge collision accidents are more and more universal. As a new type of composite material, the rubberized concrete has some good properties, such as high impact toughness, high deformability and high energy dissipation capacity. Using the rubberized concrete as an anti-collision measure of bridge piers can not only protect the bridge piers from the vehicle impact effectively, but also provide a solution to the recycling problem for the huge amount of the waste tire in our country.In this paper, the experimental study on the static mechanical properties and the energy dissipation properties under the axial compression hysteretic of the rubberized concrete material were carried out. The effects of the different partical sizes, volume fractions on the properties of the rubberized concrete were analyzed. At the same time, the vehicle-bridge pier collision processes were simulated by LS-DYNA. Finally, using the rubberized concrete as the anti-collision layer of bridge piers, the protective effect of the rubberized concrete has been discussed. The vehicle-bridge pier collision simplified dynamic model was established, and the parameters of it were analyzed. The main achievements obtained through the experiment and the analysis in this article are as follows:(1) With the increase of the volume fraction and size of rubber particles, the compressive strength and elastic modulus of the rubberized concrete decrease, and the compressive strength and elastic modulus of rubberized concrete that contains larger rubber particles decreased faster than the rubberized concrete that contains smaller rubber particles. The loss factor of the rubberized concrete increased with the loading level increasing. The effect of volume fraction on the loss factor of the rubberized concrete is more significant than the effect of the particle size. With the increase of the volume fraction of rubber particles, the increase rate of the loss factor of the rubberized concrete that contains the larger rubber particles is higher than the rubberized concrete that contains the smaller rubber particles.(2) There is a positive correlation between the vehicle-bridge pier impact force and the vehicle velocity. With the increase of the vehicle velocity, the impact force increases significantly. The vehicle weight mainly affects the duration time of the vehicle-bridge pier collision. The greater the vehicle weight, the longer the duration time of collision. Both the vehicle velocity and the vehicle weight have effects on the displacement of the bridge pier, but the influence of vehicle velocity on the displacement of the bridge pier is more significant than the influence of vehicle weight. The stiffness of the pier also has certain influence on the impact force, but not significant.(3) Using the rubberized concrete as the anti-collision layer of the bridge pier can reduce the impact force and displacement of the bridge pier, and significantly weaken the impact stress of the bridge pier in the process. It can increase the damping energy dissipation of the bridge pier. Using the rubberized concrete that contains larger size and larger volume fraction of rubber particles as the anti-collision layer of bridge piers is more effective. The influences of the impact weight, the impact velocity, the contact stiffness and the rigidity of bridge piers on the impact force were analyzed by the simplified dynamic model of vehicle-bridge pier collision. The results of the simplified dynamic model have the same change regularity with the numerical simulation.It can provide a reference for the selection of parameters of the anti-collision design of the bridge pier.