新型再生发泡混凝土墙式护栏防车撞试验与模拟

A guardrail is one of the basic means of ensuring the safety of high-grade highway traffic, and it is widely used in China. However, traditional guardrails have a high rigidity and relatively weak energy absorption capacity, which can lead to severe vehicle damage and casualties in the event of a collision. In this context, this study proposes a novel SS-grade wall-type guardrail that utilizes recycled foam concrete as a cushioning material. A certain amount of brick and concrete construction waste is used as the raw material, which offers economic advantages and green low-carbon properties. Additionally, foam concrete is combined with a thin-walled steel shell, forming an externally attached energy-absorbing component that is easy to replace, which enhances the overall recoverability of the guardrail. To evaluate the energy absorption characteristics and protective performance of this novel guardrail, full-scale vehicle impact tests and numerical simulations were conducted. The test results demonstrate that the novel guardrail exhibits favorable cushioning and energy absorption properties. After an impact, the vehicle maintains a good level of integrity; meanwhile, the steel shell shows clear guiding traces, and the foam concrete effectively absorbs energy, with a detachment rate exceeding 20%. The peak impact force reduction exceeds 54%, and the peak acceleration reduction in both the parallel and vertical guardrail directions exceeds 55% and 61%, respectively, compared to those of the traditional standard guardrail. Furthermore, a refined finite element analysis model of the vehicle and guardrail is established, and simulated impact analyses are conducted. The accuracy of the model is verified by comparing its results with the experimental results. Based on the functional requirements of the novel guardrail in terms of obstruction and guidance according to specifications, simulations of the guardrail's impact with three types of vehicles-small cars, large buses, and heavy trucks-are conducted. The results indicate that the foam concrete cushioning layer in the novel guardrail effectively mitigates the damage caused to the guardrail's concrete fixation layer and the colliding vehicles. The energy absorption increases with the level of impact energy, reaching a maximum of approximately 35%. Under all conditions, the colliding vehicles do not exhibit any phenomenon of penetration, overturning, or riding over. These results confirm the excellent obstruction and guidance functions of the guardrail during practical use and its significant potential for application.