盐雾对珊瑚骨料混凝土构筑物性能的影响及其机理

Effect and Mechanism of Salt Spray on Properties of Coral Aggregate Concrete Structure

关键词:  珊瑚骨料混凝土  盐雾作用  侵蚀劣化  孔隙  强度  微观结构

Key words:  coral aggregate concrete  salt spray effect  erosion deterioration  porosity  strength  microstructure

摘要:

针对热带海洋环境中由于盐雾作用造成的混凝土结构侵蚀破损现象，在对南海现役珊瑚骨料混凝土构筑物进行调查分析的基础上，对其进行了物理力学性能、孔隙结构以及微观机理分析.结果表明：长期暴露于高温高湿盐雾环境中的珊瑚骨料混凝土保护层发生了严重的侵蚀破坏，珊瑚骨料混凝土中的微细小孔隙向有害大孔洞转化，孔隙率明显增大，直接导致混凝土质量、强度的损失；微观层次机理认为这一过程中混凝土中C S H和Ca(OH)2流失严重，Mg(OH)2等无胶结作用的生成物增多，致使水泥石结构破坏严重.所得成果对珊瑚骨料混凝土的施工工艺设计和长期运营维护具有重要的科学指导作用.

Abstract:

For the leaching damage of seawater coral aggregate concrete caused by salt spray effect in the tropical marine environment, research of carol aggregate concrete structures in South China Sea was conducted. The physical and mechanical properties, micro pore structure deterioration analysis were carried out. The results show that serious erosion damage exists on the coral aggregate concrete protective layer exposed to salt spray environment. The little pores are transformed into larger harmful pores and the porosity increased obviously, which leads to harsh decrease in the quality、strength properties of the concrete. It is also found that the cementious structure of coral aggregate concrete is seriously damaged. The loss of C S H and Ca(OH)2 is serious, and the non cementation products like Mg(OH)2 increases. This investigation result is of important scientific guidance for the design of construction technology of coral aggregate concrete，as well as for its long term operation and maintenance.