Analysis of mechanical properties of transition segment of road and bridge based on high-strength foam concrete

Hongmei Cao

doi:10.3221/igf-esis.49.73

Abstract

The settlement difference in the transition section of road and bridge may lead to traffic accidents, which has many negative effects. Back filling of foam concrete behind abutment is a good method of treatment. In this study, a kind of high-strength foam concrete was designed for back filling of transition section of road and bridge, and the mechanical properties of the transition section of road and bridge were analyzed. It was found that only a large number of micro cracks grew in high-strength concrete under a large number of load cycles, and structural damage did not happen, indicating the high-strength foam concrete had high strength and long service life; the static base pressure was about 40 KPa, indicating a small burden on the structure. Under the vehicle load, the vertical displacement of the transition section of road and bridge with back filling of high-strength foam concrete behind abutment was about 0.7 m and the maximum vertical stress was about -40 KPa, which was significantly lower than that of the ordinary concrete, and the stability was favourable, indicating that the high-strength foam concrete had good vibration absorption effect. The analysis results verifies the value of the high-strength foam concrete as the backfill material of the transition section of road and bridge, providing some theoretical basis for its application and popularization.

Highlights

D ifferential settlement of transition segment of road and bridge is a common problem
The analysis of the high-strength foam concrete suggested that the material generated a large number of micro cracks under the action of load cycle, and the number of micro cracks increased significantly with the increase of load cycles; after 1 million 200 thousand cycles of loading, there were more than 100 thousand micro cracks in the specimen, and the residual strength was 0.51 MPa, but there was no structural damage
The analysis of the mechanical properties of the transition section of road and bridge suggested that the static base pressure of transition section of road and bridge which was processed by the high-strength foam concrete was about 40 KPa, which was much smaller than that of ordinary concrete, indicating that the load on the transition section of road and bridge was small

Summary

Introduction

D ifferential settlement of transition segment of road and bridge is a common problem. There are many methods to solve the settlement difference problem in China and abroad, such as using bridge end transition slab [8], i.e., connecting bridge abutment with roadbed through reinforced concrete slab [9], improving the degree of density of roadbed and reducing deformation by using civil engineering material with reinforced bars and loading preload, increasing rigidity of foundation by piling, and filling foundation with lightweight materials. In order to improve the material properties, a high-strength foam concrete was designed, and the good strength and stability of the material were proved by the analysis of mechanical properties It should be further popularized in settlement difference treatment

Methods

Discussion

Conclusion