Development of Analytical System for Damage and Deterioration of Concrete Structures

本研究的目的是开发一个分析系统，可以预测混凝土结构在各种荷载和环境作用下的性能。主要研究成果如下：1）编制了氯盐侵蚀下钢筋混凝土桥梁性能时变数值模拟程序。2）对上述计算系统中的材料模型进行了改进，改进后的材料模型为开裂混凝土中的材料输运模型，混凝土中钢筋的锈蚀模型和锈蚀钢筋混凝土构件的受拉刚化模型开发了能模拟不同类型钢筋混凝土结构峰后性能的三维非线性有限元程序。4）研制了裂缝混凝土气体渗透性试验装置。利用该装置，研究了受损混凝土对侵蚀剂侵入的抵抗能力。5）改进了混凝土本构模型，以确保混凝土结构在各种条件下的损伤分析。建立了平面混凝土在反复拉压应力作用下的本构模型。建立了冻融作用下平面混凝土的本构模型。建立了静载和循环荷载作用下碳纤维布与混凝土粘结性能的本构模型。

The objective of this research project is to develop an analytical system that can predict performance of concrete structures subjected to various load and environmental actions. Following results were obtained.1) A computer program for numerical simulation of time-dependent performance change of RC bridges subjected to chloride attack was developed. It can predict effectiveness of some rehabilitation techniques as desalination method and retrofitting of CF sheet on service life of structures.2) Material models in the computational system mentioned above were improved, which are material transport models in cracked concrete, corrosion model of reinforcing bar in concrete and tension stiffening model for corroded RC members.3) 3D nonlinear FEM program that can simulate post peak behavior of various types of RC structures was developed.4) A testing apparatus to examine gas permeability in cracked concrete was developed. Using this apparatus, resistance of damaged concrete against ingress of aggressive agent was investigated.5) Constitutive models for concrete were improved to ensure a damage analysis of concrete structures under various conditions. A constitutive model for plane concrete under cyclic tensile and compressive stress was formulated. A constitutive model for plane concrete damaged by freeze-thaw action was formulated. A constitutive model for bonding behavior of CF sheet and concrete under static and cyclic load was formulated.