Coupling Analysis of Temperature and Stress Field of Phase Change Concrete Box Girder(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2019年01期
- Page:
- 67-75
- Research Field:
- Publishing date:
Info
- Title:
- Coupling Analysis of Temperature and Stress Field of Phase Change Concrete Box Girder
- Author(s):
- GUO Zeng-wei; CHEN Dan; ZHOU Jian-ting; WANG Yu
- School of Civil Engineering, Chongqing Jiaotong University
- Keywords:
- bridge engineering; phase change concrete; multi cell concrete-box girder; temperature gradient; thermal stress
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to control the principal tensile stress of concrete box girder induced by temperature gradient of sunshine, phase change concrete with “structure and function” integration effect by mixing rice husk ash encapsulated paraffin as phase change material. Thermal stability of the rice husk ashparaffin phase change concrete as well as its thermal and mechanical parameters were tested by experiment, and the influence of thickness and laying position of phase change concrete on principal tensile stress of concrete box girder induced by temperature gradient of sunshine were discussed based on practical project. The results show that the rice husk ashparaffin phase change concrete has good phase change stability, and there is no serious leakage of paraffin after multiple phase change cycles, while the concrete strength decreases. The temperature on the top of box girder decreases obviously and the tensile stress of the gradient temperature decreases by 10% when the ordinary concrete with a certain thickness under the pavement is replaced by the phase change concrete. When the thickness of the pavement is equal, the maximum thermal stress on the top of box girder firstly decreases and then increases with the increase of the thickness of phase change concrete, while the thermal stresses in side web and middle web decrease monotonously with the increase of the thickness of phase change material. However, with the increase of the thickness of asphalt pavement, the improvement effect of phase change concrete layer on temperature stress decreases gradually. The roof area corresponding to the web and chamfer are sensitive parts which affect the gradient temperature stress field of box girder, while the roof area corresponding to the cantilever plate and upper part of the inner box does not affect the maximum temperature of the box girder basically. Although the number of chambers in the box girder cant change the vertical distribution of temperature in the side web, the maximum temperature stress of the box girder will increase with the increase of the chamber. The number of web slabs maybe as little as possible if the liveload bearing capacity of roof slab can meet the requirement, so the temperature selfstress can be reduced.
Last Update: 2019-01-23