Importance of using Sodium gluconate in hot regions

• July 11, 2023
• ambarish
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It is important to keep the W/C ratio constant to improve operability in hot areas. Large amounts of Sodium Gluconate were used to build bridges in the Middle East.

Adding sodium gluconate to the concrete mix can delay the setting time, which is very important for long and difficult pouring.

In the concrete industry now, ready-mixed concrete is packaged at a central location and then shipped out by mixer trucks. In this case, it is important to delay the initial setting time to increase the workability.

Related applications of sodium gluconate in the construction industry:

For example, Sodium Gluconate can be used as a water reducing agent. Sodium gluconate can be used as a retarder, which can significantly delay the initial and final setting time of concrete. It can also be used as a stabilizer for water quality, because sodium gluconate has the effect of high-quality corrosion and scale inhibition, so it is widely used as a stabilizer for water quality.

dding sodium gluconate to prefabricated masonry mortar can prolong the working period:

Prefabricated masonry mortars must be usable for a long period of time. Adding sodium gluconate can prolong the working period. Oil well grouting slurry is difficult to operate due to high temperature. After adding sodium gluconate, the mud concrete can work at 170 °C for several hours. , adding sodium gluconate can improve plasticity under the condition that water to cement (W/C) remains unchanged. 

At this time, sodium gluconate acts as a plasticizer. When the addition amount of sodium gluconate is below 0.1%, the degree of total improvement is directly proportional to the addition amount. When the cement content remains the same and the content decreases (that is, the W/C ratio decreases), when the addition amount of sodium gluconate is 0.1%, the water addition amount can be reduced by about 10%. Sodium gluconate as a cement reducer. In general, two aspects are important to concrete performance: shrinkage and heat production.

Sodium gluconate works best in retarders:

Due to the different types of retarders, their retardation effects are also very different. The same theory cannot fully explain the mechanism of retardation. The same retarder may have two or more mechanisms of action at the same time.

The organic retarder mainly slows down the hydration of C3S. Among the organic retarders, especially various hydroxycarboxylic acids and their salts, such as: tartaric acid, citric acid, apple, salicylic acid, gluconic acid and their salts are commonly used retarders, they are often fish accelerators or Accelerators are compounded together for the setting of fast-setting hard cement, among which sodium gluconate has the best effect.

The mechanism of action of inorganic retarders is that a layer of insoluble film is formed on the surface of cement particles to block the hydration process of cement. The retarding effect of inorganic salt retarders is not stable enough, so they are often not used.

The mechanism of action of excess retarder is not fundamentally different from that of general retarder, but due to the high dosage of retarder, the residual content of retarder in the liquid phase of fresh concrete is very high, whether it is adsorption. The theory, the precipitation theory, and the theory of controlling the growth of calcium hydroxide crystals all believe that the cement hydration needs to overcome a larger energy barrier at this time, so it often takes a long time, even if the cement hydration stops completely, and the coagulation cannot be completed. , resulting in a non-condensation phenomenon. This is quite dangerous for engineering and will lead to serious engineering quality accidents.