Experimental Study And Theoretic Analysis On Damage Rule Of Corroded And Cracked Reinforced Concrete

Damage pattern of corroded and cracked reinforced concrete is the base of assessment of corroded R.C. structure. In this paper, by method of test, investigation, theoretical analysis, and simulation calculation on the damage pattern of corroded and cracked R.C., the relevant problems caused by rebar corrosion are studied, and the research contents and results are as following:1. Concrete collapse patterns and crack distribution patterns caused by re-bar corrosion swelling are simulated by the tests of mechanical enlarging hole, and two mathematic model are formulated: 1) the model of concrete cover strain field changing with increasing radial swelling displacement; 2) the model of crack propagation with factors of concrete tensile strength, cover thickness, and the ratio of cover thickness and re-bar diameter c/d.2. By electrical chemical corrosion test, the appearance rule of oblique crazing and vertical crazing on concrete cover is summarized and the changing features during the crazing developing into cracks and the collapse patterns are analyzed. At last, the test specimens are broken and the corroded re-bars are obtained and measured, and based on that model of the relation of re-bar weight loss ratio and crack width is obtained.3. Test of mechanical enlarging hole is simulated by the finite element method (FEM). Simulation results and test results are in consistence and the fundamental rules of corroded concrete crack distribution are obtained. Stress field is analyzed using elastic mechanics and fracture mechanics. The results predict same cracking tendency with tests and the FEM simulation.4. Digital simulation tension tests of re-bars with different defect surface state, and different defect degree, are conducted using the FEM method. Factual bars line-dissected mechanically are stretched on test machine to verify the digital tests. It is found that defect degree of bar section and weight loss ratio are the two key factors to affect re-bar strength and a computation model of corroded re-bar ultimate strength is put forward in this paper.5. "Data management and analysis system of corrosion research" is developed and the design thought is introduced in this paper. The system can present such functions as data management, data inquiry and retrieving, data treatment, and database maintenance, which lay down a good foundation for corrosion research. Database is opening for other researchers to add other test data. All data can be derived as text document and can be chained with the professional analysis software for further research.