MICP加固钙质砂的耐久性试验研究

南海岛礁建设中，钙质砂是易于获取的原材料，但也存在孔隙多、易破碎等不足。为保证岛礁建设的安全稳定，设计经微生物诱导碳酸钙沉积(MICP)加固后钙质砂试样在海水、纯水环境下分别进行浸泡与干湿循环试验，以探究不同环境与处理方式对MICP加固钙质砂样耐久性能的影响。结果表明：(1)经MICP加固的钙质砂具有较好的抗侵蚀能力，通过增加钙质砂的加固轮次能够有效地提高试样的耐久性能，其在海水中干湿循环时劣化最快，在纯水中浸泡时劣化最慢；(2)持续浸泡与干湿循环均会对试样耐久性造成不利影响，干湿循环的劣化作用更大；(3)控制其余变量不变时，海水环境下试样耐久性能的劣化比纯水环境下更严重。

Experimental Study on Durability of MICP-solidified Calcareous Sand

In the construction of islands and reefs in the South China Sea, calcareous sand is an easily obtained raw material, but it also has disadvantages of being porous and fragile. To ensure the safety and stability of the construction of islands and reefs, the MICP-solidified calcareous sand samples are designed to undergo immersion tests and dry-wet cycles in seawater and pure water respectively to explore the durability of MICP-solidified calcareous sand samples in different environments and treatment methods. The results show that:(1) the MICP-solidified calcareous sand has good erosion resistance, which effectively improves with the increase of reinforcement rounds. It deteriorates the fastest in seawater dry-wet cycles and the slowest when immersed in pure water; (2) both immersion tests and dry-wet cycles can adversely affect the durability of the samples, and the degradation of the dry-wet cycles is greater; (3) when controlling variables, the durability of the samples in seawater is worse than that in pure water.