Study On Concrete Lining Corrosion Reason And Protection Of The Tunnel

The concrete is a very good durable material, widely applying to the structure of the bridge, the dike, the tunnel and so on. The environmental condition change causes the concrete building or the construction appears the corrosion destruction phenomenon, which arouses the widespread concern in the world scope. This paper, based on systematically introducing concrete corrosion and the present situation of its protection research, has conducted the research to some tunnel concrete lining corrosion reason and the protection in Jin Duicheng. By means of analysing the completion material, surveying, using the law of drilling the core to test the scene, this paper carries on the appraisal to the tunnel structure security, and draws the conclusion: The tunnel partial construction joint and distortion seam processing are not dense, which creates the tunnel partial percolating water, and corrodes the occurrence for the lining work to form the advantageous channel. That is the internal cause for concrete corrosion. Through making analysis to the adjacent formation characteristic, the hydrochemistry, the corrosion matter and the microbiological, the writer has verified the tunnel concrete lining corrosion reason: in the adjacent formation there includes the massive curings mineral, the tunnel geology condition changes, the sulphurize has the complex chemical reaction and causes the ground water pH value to drop, corrosionion Fe²⁺, Fe³⁺, SO₄^2-, Mg²⁺ and so on become double increasing, polluting the tunnel groundwater which are the external factor for the concrete corrosion. In the tunnel the microorganism although does not occupy the main part of the concrete corrosion, it should bring to the corresponding attention; The air is smaller to the tunnel lining concrete corrosion in harm, mainly occurring in tunnel exit. In the environment climate dry and wet changes in turn, the alternation of freezing and thawing frequency height, directly affect the concrete in corrosive medium corrosion rate, and corrode the promoter action to the concrete. The internal causes and the external factors mutually affect each other and cause the concrete corrosion, therefore we must start with improving the concrete construction quality considering the tunnel concrete lining protection and with slowing down the curing mineral oxidation rate in the government and removing the ground water to carry on.