Which of the following is a critical factor when mounting external vibration systems?

When considering the mounting of external vibration systems, the position relative to molds is critical because it directly influences the efficacy of the vibration applied to the concrete. The main purpose of mounting these systems is to enhance the consolidation of the concrete, which minimizes the risk of air pockets and optimizes the overall quality of the structure being constructed.

Proper positioning ensures that the vibrations are effectively transmitted to the concrete mix within the molds. If the vibration system is not positioned correctly, it may not reach all areas of the mold, leading to uneven compaction and potentially impacting the strength and durability of the finished product. The ideal position allows the vibrations to permeate the concrete uniformly and thus achieve the desired results in terms of density and finish quality.

Although distance from the concrete surface, type of vibration method used, and mounting height above ground are all important considerations in the setup of vibration systems, they are secondary factors when it comes to achieving the optimal outcome in the context of mold vibration. The positioning relative to the molds is paramount in ensuring that the vibrations effectively enhance the properties of the concrete during the setting process.