早强型喷射混凝土在郑万高铁巫山隧道中的施工试验

Construction T est of Rapid Hardening Shotcrete in Wushan Tunnel on Zhengzhou-Wanzhou High-speed Railway

在郑万高铁巫山隧道建设中,为降低施工综合成本,提升喷射支护效果,加快工程进度,对采用早强型速凝剂与喷射混凝土纳米掺合料制备的早强型喷射混凝土开展工程试验研究。结果表明:1)同普通喷射混凝土相比,早强型喷射混凝土一次喷射厚度提高33 mm,回弹率降低14.5%;2)30 m隧道喷射施工可节省原材料费用2.77万元,节省工序时间24 h,经济效益显著。

In order to reduce the construction cost,improve the shotcreting quality and support effect,the rapid hardening shotcrete(RHS)is prepared for Wushan Tunnel on Zhengzhou-Wanzhou High-speed Railway.The project test is carried out on RHS prepared by early-strength setting accelerator and nano-mineral admixture.The testing results show that:(1)Compared with general shotcrete,the once-sprayed thickness of RHS is 33 mm higher,the rebound rate is 14.5%lower.(2)RMB 27700 yuan of raw material cost and 24 h of working procedure time can be saved for 30 m long tunnel shotcreting,and the economic benefit is notable.