【摘要】 无黏结预应力技术在长距离有压输水隧洞中应用较少,目前锚具槽主要用普通混凝土填充,已有工程出现锚具槽混凝土振捣不密实或开裂脱空现象,影响结构安全。针对某引水工程有压隧洞工程需求,开发出具有微膨胀特性的自密实混凝土用于锚具槽回填。通过室内外试验,研究的配合比能够配制出具有微膨胀特性的自密实混凝土,膨胀性主要发生在水化初期,实体锚具槽填充效果好,混凝土浇筑方便,硬化后外观质量良好。更多还原

【Abstract】 Due to the apprehension of its structural durability, unbounded prestressing technology(UPT) has been rarely adopted for the project of long distance water conveyance tunnel. At present, the anchorage slot was usually backfilled by common concrete, and the defect of less compaction during vibrating, the fissured cavity could be found, which may impact the structural durability of the anchorage. According to the demand of long distance tunnel of a water diversion project, the micro-expansive self-compacting concrete has been developed for the backfilling of the anchorage slot of prestressing cable. According to the test result of the laboratory and the site, the developed concrete mix has the characteristic of micro-expansion occurred in the initial hydration period, with a quite well backfilling effect, placing convenience and good hardening appearance.更多还原