What is a common consequence of air bubbles in a plaster mixture?

The presence of air bubbles in a plaster mixture can lead to a decrease in the overall strength of the hardened plaster. When air bubbles form, they create voids within the material, which compromises the continuity and integrity of the plaster matrix. This can result in a weaker structure that is more prone to cracking or breaking under stress.

Therefore, the correct answer emphasizes how these air pockets interfere with the bonding capabilities of the plaster particles. High-density and strong plaster requires as few voids as possible. When air bubbles remain trapped in the mixture and are not properly eliminated through mixing and vibration, the final product does not achieve its full potential in terms of strength.

On the other hand, the other potential consequences mentioned in the choices, such as affecting density and accuracy, are not main concerns compared to the significant impact on strength. While they can be interconnected, the critical issue with air bubbles is fundamentally about compromising the strength of the final product. Decreasing drying time is also not a typical consequence of air bubbles; in fact, the presence of air might hinder effective drying, as areas with trapped air can retain moisture longer than desired.