A key parameter of the concrete mix ratio is the water/cement ratio, that is, the ratio of water/cementitious material (cement + active mineral mixture). The higher the water/glue ratio, the better the workability of fresh plastic concrete and the easier it is to construct, but the lower the strength of hardened concrete. In order to solve this contradiction, that is, to increase the strength without sacrificing workability, or to reduce the cement dosage while maintaining workability and strength, it is necessary to add a water-reducing agent.
Water reducing agent (including ordinary type, high efficiency type and super high efficiency type) is already one of the indispensable raw materials for concrete materials. In the low strength grade range (below C30), the use of water-reducing admixtures can reduce the cement dosage and cost, while improving the workability of plastic concrete. In the medium strength grade range (C40~C50), it is generally necessary to use a water-reducing agent (ordinary or high-efficiency) to ensure the workability (pumpability) and strength of concrete. For high-strength concrete (above C50), without the use of high-efficiency or ultra-high-efficiency water-reducing agents, the concrete has basically no workability. Unless small prefabricated components are formed by strong vibration, cast-in-place concrete cannot be constructed.
Therefore, the commercial value of water-reducing admixtures lies in: 1) reducing the finished product; 2) it must be used to improve the workability and strength of plastic concrete.
The essential function of water reducing agent is to reduce the water consumption of concrete.
The strength of concrete has a great relationship with the water-cement ratio. At a certain slump, the smaller the water consumption, the higher the strength.
The addition of water reducing agent can reduce water consumption while keeping the slump unchanged, thus increasing the strength of concrete.
If your strength and slump remain unchanged and you add a water-reducing agent, you can use less cement, thus reducing the cost of concrete. Of course, It depends on the price of the water-reducing agent you buy. If it is too expensive, it will definitely not reduce the cost. Let’s put it this way, we are an admixture factory. When we build our own factories, we will use water-reducing agents. It is definitely better to use water-reducing agents. Cost-effective.
There are also times when you have to use water-reducing agents (admixtures), otherwise your concrete will not be able to meet actual needs.
When you make high-grade concrete, the amount of cement per concrete should not be too high, otherwise excessive heat of hydration will cause temperature difference cracks. When the amount of cement is limited to a range If you want to improve the strength of concrete, you can only reduce the water consumption. Reducing the water consumption cannot guarantee the construction performance, so you need to add a water-reducing agent.
The other is long-distance transportation, or when there are requirements for the condition of concrete. During long-distance transportation, if no admixtures are added (water-reducing admixture plus other retarders and other ingredients), the concrete will dry out halfway and the concrete will no longer be usable. There are also some that require dense steel bars, require pumping, and require self-leveling. Without water-reducing agent, your concrete cannot achieve the construction performance, so you must use it.
To give a few examples, high-grade concrete such as highways, high-speed railways, and pillars in other house constructions must use water-reducing agents to achieve that level. High intensity.
In addition, the mixing station must use a water-reducing agent (strictly speaking, it is not a pure water-reducing agent, but a water-reducing agent compounded with other materials) , otherwise it cannot be transported over long distances or pumped. Water-reducing admixture must be used for pumping concrete in high-rise building construction.
Water-reducing agents are closely related to infrastructure construction, and the market is not small. Haha, the first-tier cities are saturated, and there are still second-tier and third-tier cities. There is something to be done.
Incorporating concrete admixtures into ordinary concrete can improve the physical and chemical properties of concrete. There are things such as improving concrete strength, construction speed, project quality, improving technology and labor conditions, etc. It has now become the fifth essential component material of concrete besides cement, sand and water.
In recent years, from the total output of high-efficiency water-reducing admixtures in my country, about 80% are naphthalene-based water-reducing admixtures. Naphthalene-based high-efficiency water-reducing agent has sufficient raw material supply and relatively moderate price.
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