What types of high-efficiency water reducing agents are there? There are many varieties of high-efficiency water-reducing agents. The commonly used ones are naphthalene-based water-reducing agents, melamine-based and modified melamine-based water-reducing agents, sulfamate-based water-reducing agents, aliphatic water-reducing agents, and anthracene-based water-reducing agents. The agent and washing oil are water-reducing agents. Let's take a look at what types of high-efficiency water reducing agents there are!
High-efficiency water-reducing agents are different from ordinary water-reducing agents in that they have a higher water-reducing rate and lower air entrainment capacity. The main types of high-efficiency water reducing agents currently used include the following:
1. Naphthalene series high-efficiency water reducing agent
Naphthalene-based water reducing agents can be divided into high-concentration products (Na2SO4 content less than 3%), medium-concentration products (Na2SO4 content 3%~10%) and low-concentration products (Na2SO4 content greater than 10%) according to the Na2SO4 content in the product. Naphthalene-based water-reducing admixture is the most widely produced and widely used high-efficiency water-reducing agent in my country (accounting for more than 70% of the water-reducing agent consumption). It is characterized by high water reduction rate (15% to 25%), no air entrainment, little impact on setting time, good adaptability to cement, can be used in conjunction with various other admixtures, and is relatively cheap.
2. Melamine series and modified melamine series high-efficiency water reducing agent
It is a product of the condensation of melamine with formaldehyde after sulfonation with sulfuric acid, so 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 dispersibility in powdery materials, has a high water-reducing rate, and has good fluidity and self-healing properties.
3. Sulfamate series high-efficiency water reducing agent
Sulfamate high-efficiency water-reducing agent is a monocyclic aromatic hydrocarbon high-efficiency water-reducing agent. It is mainly composed of p-aminobenzenesulfonic acid, monocyclic aromatic hydrocarbon derivatives phenolic compounds and formaldehyde, which are heated and condensed under acidic or alkaline conditions. The molecular structure of sulfamic acid water-reducing agent is relatively complex, and different monomers will have different molecular structures. The main chain of sulfamic acid superplasticizer is alternately connected by phenyl and methylene groups. The main chain contains a large number of branch chains with hydrophilic functional groups such as sulfonic acid groups, amino groups, and hydroxyl groups.
4. Aliphatic (aldehyde and ketone condensate) high-efficiency water reducing agent
Aliphatic high-efficiency water reducing agent is carbonyl pyroaldehyde synthesized by sulfonation of polymers, and the main chain of the hydrophobic group is aliphatic hydrocarbons. This high-efficiency water-reducing agent has wide applicability to cement, has obvious reinforcing effect on concrete, and has small slump loss. Small size, no sodium sulfate crystallization at low temperature. It is widely used in the preparation of various personalized water-reducing agents such as pumping agents, retardants, early strength agents, antifreeze agents, air-entraining agents, etc. It can also be used in combination with naphthalene-based water-reducing agent, amino water-reducing agent, and polycarboxylate water-reducing agent.
5. Anthracene-based high-efficiency water-reducing agent
The tan powder obtained by sulfonation, hydrolysis condensation, neutralization and atomization drying of crude anthracene is non-toxic, odorless and does not contain chloride ions. It has the characteristics of high water reduction rate, low air entrainment volume, and high reinforcement during concrete mixing. The concrete mixture has good construction workability, is not easy to bleed and segregate, and is suitable for concrete with C10~C60 strength levels.
6. Oil-washing high-efficiency water-reducing agent
Using coking wash oil, another by-product of coal coking, as raw material, we use a production process similar to that of naphthalene-based water-reducing agents to produce polycyclic aromatic hydrocarbon sulfonate formaldehyde condensate, whose performance is similar to that of naphthalene-based water-reducing agents. It is a high-efficiency water-reducing agent with wide sources of raw materials, low cost and great industrial value.