Water-reducing admixtures can mainly improve the strength of mortar and are admixtures with water-reducing and reinforcing effects; with the continuous advancement of science and technology, the application of polycarboxylic acid-based water-reducing agents has also made great progress, because of its It has been widely used in hydraulic concrete due to its high water reduction rate, strong adaptability to cement, and convenient construction. The compatibility between polycarboxylate superplasticizer and cement is not good, and the concrete mixture is prone to problems such as segregation, bleeding, increased slump loss, and shortened setting time, making the concrete mixture unable to be transported and poured normally. Reduce the strength and durability of concrete. Summer is here. Are water-reducing admixture products afraid of heat? This is a topic we are more concerned about. Generally speaking, those with a water-reducing rate greater than 8% are called high-efficiency water-reducing agents. There are many types of water-reducing agents. Function, let’s get to know it with the editor.
How water-reducing agent works: Water-reducing agent is usually a surfactant, which is an anionic surfactant. It is adsorbed on the surface of cement particles so that the particles display electrical properties. The particles repel each other because they have the same charge, causing the cement particles to be dispersed and release excess water between particles to produce water reduction. On the other hand, after adding the water reducing agent, an adsorption film is formed on the surface of the cement particles, which affects the hydration rate of the cement, makes the growth of cement stone crystals more perfect, reduces the capillary gaps for water evaporation, and the network structure is denser, improving the Improves the hardness and structural compactness of cement mortar.
Regarding whether water-reducing agent products are afraid of heat? Let’s take a look at the functions of water-reducing agents: dispersing cement particles, improving workability, reducing water consumption, thereby improving the density and hardness of cement-based materials , increasing its liquidity.
Types of water-reducing agents include lignosulfonate, naphthalene-based water-reducing agent, melamine-based water-reducing agent, polycarboxylate water-reducing agent, casein water-reducing agent, and sulfamate Water reducing agent, acrylic water reducing agent, etc.
The following introduces several water-reducing agents that are widely used in the market:
Lignin sulfonate: It is an ordinary water-reducing agent, and its raw material is lignin. Extracted from coniferous trees, lignin is polymerized from three lignin monomers: p-aralenol, coniferyl alcohol, and sinapyl alcohol. It can be used in mortar to improve workability, fluidity, strength, and water reduction rate. 5%-10%.
Naphthalene sulfonate water-reducing agent: It is the earliest high-efficiency water-reducing agent used in my country. It is the product of naphthalene sulfonation through sulfuric acid and then condensation with formaldehyde. It is an anionic surfactant. The appearance of this type of water reducing agent can be light yellow to dark brown powder depending on the product. It is easily soluble in water and has good dispersion effect on many powder materials such as cement. The water reducing rate can reach 25%.
Melamine water-reducing agent: It is the product of melamine sulfonated with sulfuric acid and then condensed with formaldehyde. Therefore, the chemical name is sulfonated melamine formaldehyde resin, which is an anionic surfactant. This type of water-reducing agent appears as white powder, is easily soluble in water, has good dispersion of powder materials, has a high water-reducing rate, and has good fluidity and self-healing properties.
Powder polycarboxylate: It is a new high-performance water-reducing agent developed in recent years. It has excellent water-reducing rate, fluidity, and permeability. It can significantly enhance the strength of cement mortar, but the production process is complicated and the price is generally higher.
Are water-reducing agent products afraid of heat? Everyone has a certain understanding. Before use, understanding the relevant precautions for water-reducing agent products is also very helpful for production.
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