Effect of excessive water addition on concrete strength

October.22,2024

Effect of concrete hardening performance
Randomly adding water will destroy the water-binder ratio of the concrete mix, directly causing the concrete strength to decrease and affecting its durability.

If the water-binder ratio of C30 concrete is 0.50, that is, the water consumption of 100kg cementitious material is 50kg, and the water-binder ratio of C25 concrete is 0.56, that is, the water consumption of 100kg cementitious material is 56kg, it can be seen that for the same 100kg cementitious material, the concrete strength differs by one level with only a difference of 6kg of water consumption.

In addition, the evaporation of excess water will inevitably produce excess voids in the hardened concrete, and the compactness of the concrete will be poor. The poorly compacted concrete will have a reduced ability to resist penetration, corrosion and carbonization.

Reduced strength of concrete

During the construction process, the slump of concrete must be strictly controlled. The reason is simple. During the hardening process of concrete, part of the water reacts chemically with cement, while the other part of the water continues to evaporate, forming voids in the hardened concrete. The more water there is, the more voids there are in the concrete, which reduces the density of the concrete and thus reduces its strength.