What is the effect of adding too much water to a concrete mix?

Adding too much water to a concrete mix primarily leads to decreased strength and increased permeability. When excess water is introduced into the mix, it dilutes the cement paste, reducing the overall cement-to-water ratio. This higher water-to-cement ratio negatively impacts the concrete's compressive strength, as the additional water creates voids once it evaporates during curing. These voids result in a less dense and less durable material, making the concrete more susceptible to cracking and other forms of deterioration over time.

Increased permeability occurs because of these voids, allowing water and other substances to penetrate the concrete more easily, which can lead to further damage from freeze-thaw cycles or chemical attack. This combination of decreased strength and increased permeability is critical for understanding how water content affects the overall quality and longevity of concrete structures.