Common Mistakes to Avoid During Shotcrete Prep

1. Common Mistakes to Avoid During Shotcrete Prep Shotcrete, a method of spraying concrete onto a surface at high velocity. However, the effectiveness of shotcrete heavily depends on thorough and proper preparation. Poor shotcrete prep work can lead to structural failure, reduced longevity, or unnecessary repairs. Whether you’re working on a residential or commercial project, here are some common mistakes to avoid during shotcrete prep to ensure a durable and high-quality outcome. 1. Ignoring Surface Cleanliness One of the most frequent and costly errors is applying shotcrete to a dirty or poorly prepared shotcrete retaining wall. Dust, oil, mud, and loose debris can prevent proper adhesion, leading to delamination or weak bonding. Surfaces should be thoroughly cleaned and, if needed, roughened to allow the shotcrete to grip effectively. 2. Overlooking Moisture Control Shotcrete performs best when applied to a damp—but not saturated—surface. Completely dry substrates can absorb water from the shotcrete mix, affecting hydration and causing shrinkage cracks. Conversely, waterlogged surfaces can

2. interfere with the material’s setting. Moisture levels must be carefully managed during prep. 3. Failing to Check Structural Stability Before applying shotcrete, ensure that the formwork, reinforcement, or existing structure is stable and properly secured. Any movement during spraying can lead to uneven layers, weak points, or wasted material. Always inspect and reinforce the framework if necessary. 4. Inadequate Reinforcement Positioning If the shotcrete layer involves steel reinforcement, its correct placement is critical. Rebar or mesh that is too close to the surface may become exposed, while poorly anchored mesh may shift during application. Ensuring reinforcement is positioned and supported correctly is essential for strength and safety. 5. Skipping the Test Panel or Mock-Up Especially on larger or specialised projects, a shotcrete test panel allows teams to evaluate nozzle technique, material consistency, and finish quality before applying it to the main surface. Skipping this step may result in inconsistency or a finish that doesn’t meet the project’s standards. By giving attention to surface prep, moisture levels, reinforcement placement, and design specs, contractors can maximise the performance and reliability of shotcrete in any project. Source: https://hennellyshotcreteandsteelfixing.blogspot.com/2025/08/common- mistakes-to-avoid-during.html