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Multi-scale Structural Evaluation Method of Reinforced Concrete Member under the Effect of Frost Damage
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| Title: | Multi-scale Structural Evaluation Method of Reinforced Concrete Member under the Effect of Frost Damage |
| Other Titles: | 凍害を受けた鉄筋コンクリート部材のマルチスケール構造性能評価法 |
| Authors: | WANG, Zhao Browse this author |
| Keywords: | frost damage | | reinforced concrete structure | | meso-macro simulation | | structural analysis | | rigid body spring model | | finite element method |
| Issue Date: | 25-Sep-2019 |
| Publisher: | Hokkaido University |
| Abstract: | Frost damage is one the most important durability issues for reinforced concrete structures built in cold and wet areas. Once frost damage initiates, cracks are induced and enlarged in concrete which leads to severer strength and stiffness reduction. Besides, the bond between concrete and reinforcement bars is also weakened due to the degradation of concrete cover and concrete-reinforcement interface. As a result, the structural behaviors usually show significant deterioration and the lifetime of structures is shortened under the effect of frost damage. Thus, to predict and evaluate the reinforced concrete structural performance under frost damage is urgently needed so that effective maintenance and repairment could be proposed.
In fact, several scales exist for the fundamental mechanisms of frost action to the structural performance with frost damage: (1) pore pressures owing to ice formation initiate in microscale which accounts for the propagation of meso-cracks in concrete; (2) the meso-cracks result in the macroscopic residual deformation of concrete, strength and stiffness reduction of concrete and deteriorated bond properties; (3) the degradation of concrete material and bond in macroscale material level is further upscaled into structural level to affect the structural performance. This study has developed a multi-scale evaluation methodology for reinforced concrete structures under the effect of frost damage following the above-mentioned “material (micro-meso-macro)-structure” system.
The methodology starts from explaining the mechanism of frost action in the porous skeleton. Both strengthening effect of elastic properties due to ice-filled pores and damaging effect by meso-cracks due to internal pressures are considered by implementing the comprehensive strengthening/damaging models into the mesoscopic simulation application – RBSM (Rigid Body Spring Model). 2D RBSM is adopted for the meso-macro simulation of concrete with frost damage while axisymmetric RBSM is newly developed to simulate the bond degradation. Based on the parametric study of simulation results, macroscale deterioration constitutive models of material and bond are proposed, and various experimental data are used to verify the models. The deterioration constitutive models are further upscaled and integrated into the 3D structural analysis with FEM (Finite Element Method). The structural behaviors of reinforced concrete beam are analyzed with this methodology and experiments are conducted to demonstrate its applicability. |
| Conffering University: | 北海道大学 |
| Degree Report Number: | 甲第13794号 |
| Degree Level: | 博士 |
| Degree Discipline: | 工学 |
| Examination Committee Members: | (主査) 特任教授 上田 多門, 教授 杉山 隆文, 教授 松本 高志, 准教授 松本 浩嗣 |
| Degree Affiliation: | 工学院（北方圏環境政策工学専攻） |
| Type: | theses (doctoral) |
| URI: | http://hdl.handle.net/2115/79177 |
| Appears in Collections: | 課程博士 (Doctorate by way of Advanced Course) > 工学院(Graduate School of Engineering)
学位論文 (Theses) > 博士 （工学）
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