跨海地铁盾构隧道管片混凝土外加剂选型及配合比设计

Selection of Admixtures and Mix Proportion Design of Concrete Used in Cross-sea Subway Shield Tunnel Segments

以厦门轨道交通2号线海沧大道到东渡路站跨海段盾构管片生产为例,通过借鉴海工高性能混凝土技术和外加剂技术,重点关注混凝土耐久性指标,采用了大掺量矿物掺合料混凝土的技术路线,成功解决了该方案早期强度难以满足管片生产模板周转的问题,制备出的C55高性能混凝土不仅工作性能良好,抗压强度、耐久性指标大大优于设计指标,而且完全能够满足管片生产1天2轮周转的要求,同时由于采用较多的矿物掺合料,水泥用量很少,在经济性和节能减排方面具有较大的优势。

Takingthe production of shield tunnel segments from Haicang avenue to Dongdu road station of Xiamen rail transit line 2 as an example,by learning from offshore high-performance concrete technology and admixture technology,focusing on concrete durability indicators,the use of the technical route of high-volume mineral admixture concrete has successfully solved the problem that the early strength of this scheme is difficult to meet the turnover of the segment production formwork.The prepared C55 high-performance concrete not only has good working performance,but also has excellent compressive strength and durability.According to the design index,it can fully meet the requirements of 2 rounds of turnover per day for segment production.At the same time,due to the use of more mineral admixtures,the cement consumption is very small,which has great advantages in terms of economy and energy saving andemission reduction.