What is a potential consequence of improper use of external vibration on precast concrete products?

Using external vibration on precast concrete products has specific benefits when done correctly, primarily to ensure proper consolidation of the mix and to eliminate air pockets. However, improper application of external vibration can lead to several negative consequences, among which decreased strength is particularly significant.

When vibration is applied excessively or incorrectly, it can cause the segregation of the concrete mix. This means that the heavier components may settle at the bottom while the lighter aggregates rise to the surface. This segregation can weaken the structural integrity of the concrete, leading to lower strength and potentially compromising the overall durability of the product. Furthermore, if air bubbles are not adequately removed, this can lead to voids in the concrete, which are detrimental to its strength as well.

Understanding the effects of vibration on concrete is crucial in the manufacturing process, and it's important to control the duration and intensity of vibration to avoid these issues. In contrast, while increased curing speed, enhanced aesthetic appeal, and improved durability may be potential benefits of proper vibration, they do not address the fundamental issues caused by its improper use, making decreased strength the primary consequence in this context.