What is indicated by a reduction in concrete strength?

A reduction in concrete strength is primarily indicated by excessive water content in the mix. When too much water is added to the concrete, it can lead to a condition known as "water-cement ratio" imbalance. The water-cement ratio is crucial because it influences the hydration process, bonding, and ultimately, the strength of the cured concrete. If the water content is too high, it increases the porosity of the concrete, making it weaker and more susceptible to cracking and other structural failures.

While improved curing practices, correct material proportions, and efficient mixing techniques are important for achieving strong concrete, they do not directly relate to the reduction in strength caused by excess water. Proper practices in these areas would typically contribute to maintaining or enhancing the strength of the concrete rather than diminishing it.