Corrosion Mechanism of the Main Shaft Wall in the Liuyuanzi Coal Mine and Appropriate Countermeasures

摘要

The concrete wall of the main shaft of the Liuyuanzi coal mine in Gansu Province, China, experienced serious corrosion less than 3 years after its completion. To deal with the issue, we analyzed the quality of the wall percolates and the composition of the corrosive products and observed the concrete's microstructure. The concrete had suffered severe gypsum-expansioninduced damage caused by the high concentration of sulfate ions in the percolates and the loose structure of the concrete. Based on these findings, the water-seepage sites behind the wall were sealed with grout and the concrete wall was coated with silane. Now, 2 years after treatment, no new corrosion damage has been observed. This study provides a reference for prevention and control of similar engineering problems elsewhere.