隧道衬砌混凝土溶蚀破坏机理及改善方法

Mechanism and Improvement of Corrosion Failure of Tunnel Lining Concrete

围绕隧道衬砌混凝土溶蚀破坏形成机理,分析溶蚀结晶体物相组成,结合混凝土耐腐蚀方法,提出针对性处治措施。结论表明:溶蚀破坏分为软水溶蚀、化学腐蚀和生物侵蚀;溶蚀破坏会引起衬砌渗水,降低结构承载能力,导致粉化劣解,降低使用寿命;为提高抗渗性能,在满足和易性前提下应尽可能降低衬砌混凝土水胶比,提高其本身致密性;还可以适当掺入一定比例硅灰来提高抗腐蚀性能;衬砌混凝土试件在浸泡环氧硅烷渗透剂后,强度增加12.2%,钙离子溶出率下降49.4%,因此可通过在已施工后的混凝土表面喷涂环氧硅烷渗透剂等方法,增强其防水防腐性能。

Based on the formation mechanism of the dissolution failure of tunnel lining concrete,the phase composition of the dissolution crystal was analyzed,and the corresponding treatment measures were put forward based on the concrete corrosion resistance method.The results show that the corrosion damage can be divided into soft water corrosion,chemical corrosion and biological erosion.Corrosion failure will cause lining seepage,reduce the bearing capacity of the structure,lead to degradation,reduce the service life.In order to improve the impermeability,the water-cement ratio of lining concrete should be reduced as far as possible to improve its compactness under the premise of meeting the workability.A certain proportion of silica fume can also be added to improve the corrosion resistance.The strength of lined concrete specimens increased by 12.2%and the dissolution rate of calcium ions decreased by 49.4%after being soaked in epoxy silane penetrant.Therefore,the waterproof and anticorrosive properties of lined concrete specimens can be enhanced by spraying epoxy silane penetrant on the surface after construction.