海砂混凝土建筑的耐久性提升技术及应用研究

Technology for Enhancing Durability of Structures of Sea-sand Concrete and Its Application

对海砂海水浇筑的钢筋混凝土板进行了双向电渗实验。结果表明,位于电解液保持装置外侧12.0 cm处的钢筋周围均有Cl-排出和阻锈剂迁入。提出了依据电通量等效原则,通过混凝土实测及安全电压,计算工程应用所需的电流密度和通电时长。最后,对海砂混凝土建筑进行了双向电渗。结果表明,有机物浓度和有害Cl-浓度比值远大于1.0。室内实验和工程应用均表明,双向电渗起到了良好的除氯阻锈效果,为我国已存的大量海砂建筑的耐久性提升提供了一种有效手段。

As one type of typical nondestructive technique of life extension, bi-directional electro- migration （BIEM） can enhance the durability of concrete structures, which suffered from chloride attack. During the BIEM process, rust-inhibitor can be migrated inward to the surface of steel bar while the chloride can be extracted out of the concrete cover. This paper applied the BIEM tech- nique to reinforced concrete slabs poured with sea sand and seawater. The results showed that the migration of rust-inhibitor and the extraction of chloride could be realized for the reinforcing bars located within a range of 12 cm from the lateral side of an electrolyte maintaining device. In accor- dance with the electron flux equivalent principle, the needed time and current density for realizing the practical engineering applications could be calculated from the measured voltage and safety voltage of concrete. A trial application of BIEM to several engineering concrete structures with sea sand proved that the ratio of organics content to the chloride concentration was far above 1.0. Con- sequently, both of the laboratory experiment and the engineering applicant indicated that BIEM technique could play an excellent role in chloride extraction and rust resistance, thus could act as an effective method for enhancing the durability of the existed sea sand containing structures.