Wet-mix shotcrete, a critical advancement in concrete application technology, has revolutionized construction practices in tunneling, slope stabilization, and underground engineering. Compared to traditional dry-mix methods, this technique offers significant technical, environmental, and economic benefits. Below is a detailed exploration of its advantages based on industry practices and research findings.

   1. Enhanced Quality and Structural Performance

   Wet-mix shotcrete ensures superior control over the water-cement ratio during premixing, leading to a homogeneous mixture with optimized hydration . This results in:

   ① Higher compressive strength: Studies show that wet-mix shotcrete achieves 28-day strengths exceeding 40 MPa, outperforming dry-mix methods by 15–30% due to reduced porosity .

   ② Improved durability: Reduced permeability and better resistance to chemical corrosion, especially when combined with additives like silica fume or synthetic fibers .

   ③ Uniform material distribution: Pre-mixed concrete minimizes segregation, ensuring consistent quality in challenging environments like tunnels or slopes .

  2. Reduced Environmental and Health Hazards

   Wet-mix technology significantly mitigates occupational risks:

   ① Lower dust emissions: By premixing water and cement, airborne particulate matter is reduced by 70–90% compared to dry spraying, protecting workers from respiratory issues .

   ② Minimized chemical exposure: The use of liquid or low-alkali accelerators (e.g., pH-neutral additives) avoids skin irritation and long-term health risks .

   3. Operational Efficiency and Cost Savings

   Modern wet-mix shotcrete systems integrate automation and advanced machinery:

   ① Higher productivity: Hydraulic pump-driven systems enable continuous spraying at rates of 10–30 m³/h, reducing labor and time costs .

   ② Lower rebound rates: Rebound losses are typically <15%, compared to 30–50% in dry-mix methods, saving material costs .

   ③ Adaptability: Equipment like robotic sprayers allows precise application in complex geometries (e.g., tunnel arches) without manual adjustments .

   4. Versatility in Application

   Wet-mix shotcrete excels in diverse scenarios:

   ① Tunnel linings: Provides immediate structural support in soft ground conditions, reducing deformation risks .

   ② Slope stabilization: Combines with steel fibers or mesh for erosion control in geologically unstable areas .

   ③ Repair and retrofitting: Effective for restoring aging infrastructure due to its adhesion properties and rapid curing .

  5. Sustainability and Long-Term Benefits

   ① Reduced material waste: Precise mixing and application minimize over-spray and resource consumption .

   ② Extended service life: High-performance mixtures (e.g.,掺入硅灰或聚合物) enhance resistance to freeze-thaw cycles and abrasion, lowering maintenance costs .

   Wet-mix shotcrete represents a paradigm shift in construction technology, addressing quality, safety, and efficiency challenges inherent in older methods. As evidenced by its adoption in major projects like the Three Gorges Dam and urban metro systems , this technique is poised to dominate future infrastructure development. Continued innovation in additives and equipment will further solidify its role as a cornerstone of modern engineering.