Water reducing agent in concrete

There has two roles on concrete quality when mixed the right amount of water reducing agent with concrete:

1 Mixed with the right amount of water reducing agent without changing the case of a concrete mix ratio and water/cement ratio, which can enhance the fluidity of concrete without reduce the concrete strength.

2 Water/cement ratio can be reduced while maintaining the fluidity and cement use amount unchanged. Due to the reduction of water consumption makes concrete density increase, thereby increase the strength and durability of concrete.

According to the composition of materials, water reducing agent can be divided into water sulfonate, polynuclear aromatic salts and water-soluble resin sulfonate. Sort by setting time it can be divided into standard type, early strength and retarding type. In accordance with the participation of composition, it can be divided into ordinary water reducers, superplasticizers, early strength water reducer and air-entraining water reducing agent.



The economic effect of adding water reducing agent to concrete are as follows:

1 keep the mix ratio of concrete unchanged, this can significantly increase the fluidity of concrete;

2 maintain the fluidity of concrete and cement usage does not change, it can reduce the amount of water and increase strength;

3 maintain the fluidity and strength intact to reduce the amount of cement;

4 keep the concrete liquidity requirements unchanged can reduce the amount of water and increase the frost resistance and impermeability of concrete;

5 delay the hydration of cement and reduce the thermal stress of mass concrete, as well as reduce the possibility of cracking.

Studies show that after joining the reducing agent, the hydrophobic group of reducing agent oriented adsorption on the surface of cement particles, hydrophilic point to the aqueous and form a single molecule or molecules adsorbed film.
Due to the adsorption dispersion, moist and lubricated, just use a small amount of water can easily mix concrete evenly, so as to improve the workability of the fresh concrete.

Because of the dispersion of water reducing agent, this keeps the cement particles more isolation and makes early hydration increases the reaction area of cement particles. Hydration reaction of cement of this stage in the process of dissolution - hydration - crystallization. While filming of water reducing agent would hinder the reaction, but its impact is small,but its overall effect is to increase the speed of initial hydration. If you have interest in water reducing agent and other construction chemicals, please click here!
Source: https://www.okchem.com/news/water-reducing-agent-concrete.html