热带海洋环境下珊瑚混凝土研究综述

Review of Research on Coral Concrete in Tropical Marine Environment

摘要: 我国在热带海洋环境和中南海岛礁基础上仍缺乏我国大陆最常见到的天然砂石，其中珊瑚礁岛(砂)化石资源较丰富。珊瑚混凝土作为一种特殊的建筑材料，在海洋环境和特定工程领域具有潜在应用价值。然而，其耐久性能特别是抗氯离子渗透性和抗碳化性能一直是研究的热点。多项研究表明，珊瑚混凝土相较于普通混凝土在抗氯离子渗透性方面存在不足，但添加偏高岭土(MK)等添加剂可以显著增强其抗氯离子渗透能力。此外，珊瑚混凝土中的钢筋容易受到氯离子渗透导致的腐蚀影响，而掺入氨基醇类阻锈剂或采用抗硫酸镁水泥等措施可以有效减缓钢筋的锈蚀速率。养护龄期的延长和混凝土强度等级的提高也有助于降低珊瑚混凝土表面氯离子浓度及其增长速率。在抗碳化性能方面，珊瑚混凝土通常不如普通混凝土，但添加偏高岭土等添加剂可以提高其抗碳化性能。冻融循环对珊瑚混凝土的性能有不利影响，而添加粉煤灰等添加剂可以减少冻融循环带来的损失。这些研究为珊瑚混凝土在实际工程应用中的耐久性设计和优化提供了重要参考。

Abstract: Given the tropical marine environment and the presence of coral reefs and islands in the South China Sea, China still lacks the natural sandstone commonly found in mainland of China, with coral reef (sand) fossil resources being relatively abundant. Coral concrete, as a special building material, has potential application value in marine environments and specific engineering fields. However, its durability, especially chloride ion permeability and carbonation resistance, has always been a research focus. Numerous studies have shown that coral concrete is inferior to ordinary concrete in terms of chloride ion permeability, but the addition of additives such as metakaolin (MK) can significantly enhance its chloride ion permeability resistance. Additionally, the steel bars in coral concrete are prone to corrosion caused by chloride ion penetration, while the incorporation of amino alcohol corrosion inhibitors or the use of magnesium sulfate-resistant cement can effectively slow down the corrosion rate of steel bars. Extending the curing age and increasing the concrete strength grade also helps reduce the chloride ion concentration on the surface of coral concrete and its growth rate. In terms of carbonation resistance, coral concrete is generally inferior to ordinary concrete, but the addition of additives such as metakaolin can improve its carbonation resistance. Freeze-thaw cycles have an adverse effect on the performance of coral concrete, while the addition of additives such as fly ash can reduce the losses caused by freeze-thaw cycles. These studies provide important references for the durability design and optimization of coral concrete in practical engineering applications.