Abstract: The shotcrete supporting technology is essential part of the tunnel construction. Among other potential factors, the concrete accelerator has an important impact on the quality of the shotcrete. A new composite and high performance liquid concrete accelerator agent is used in the tunnel project in Baoyi highway tunnel construction. It is consists of several components and has the characteristics of small application amount, wide applications, and small strength loss. This agent is approximately 1.5% to 3% of the cement weight and the initial setting time is approximately one minute and the final setting time is within four minutes. The strength loss at the later stage is within 10%. The application results indicate that this liquid agent has characteristics of small rebound and waste slurry.

Key words: Liquid Concrete Accelerator, High Performance Compound, Shotcrete, Tunnel Engineering