在对混凝土锈胀开裂破坏过程进行阶段划分的基础上,从锈蚀参数概念出发,利用变形协调原理导出了锈蚀物填充范围、锈蚀钢筋直径膨胀增量、锈胀作用临界锈蚀率、铁锈物膨胀系数、混凝土开口空隙率及锈蚀钢筋初始直径等各参数之间的关系,建立了计算锈蚀自由膨胀阶段铁锈物质渗入混凝土层的填充范围相对值的数学模型,并推导了锈胀连续作用阶段计算锈胀主压应力的理论模型.利用室内锈胀试验成果与锈胀二维数值模拟结果进行对比的方法,验证了所建立理论模型的可靠性与适用性.模型将为混凝土耐久性设计及寿命评估提供理论参考.
The rebar corrosion process is newly partitioned in this paper.Based on the concept of corrosion parameters and principle of deformation harmony,the relation among the parameters of δ,δ′,η0,n,PK and d0,is deduced,and which are respectively represented iron rust filling zone,increment of corrosion rebar diameter,critical rustiness rate,coefficient of rust expansion,opening voids within concrete and steel initial diameter.A model of calculating rust filling zone relative value δ/d0 on a free expansion stage is built up,and a theoretical model of calculating main pressure stress value q* due to rust expansion on expansion force formation stage is also set up according to mass conservation law.It is verified to be reliable and suitable for the calculation models by indoor test result analysis and also proved to be correct by the corrosion expansion ANSYS simulation trial.The models is useful for forecasting service life of concrete.