The role of common mortar additives such as rubber powder


Release time:

2020-05-15

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1. Redispersible latex powder
Redispersible emulsion powder is a kind of powder organic binder made by spray drying of special emulsion (high molecular polymer). This powder in contact with water can be quickly redispersed into an emulsion, and has the same properties as the initial emulsion, that is, water evaporation can form a film, the film has high flexibility, high weather resistance and high adhesion to a variety of substrates.
Re-dispersible emulsion powder is an essential basic raw material for dry-mixed mortar. It can improve the performance of mortar, increase the strength of mortar, increase the bond strength between mortar and various substrates, and improve the flexibility and deformability of mortar. Compressive strength, flexural strength, wear resistance, toughness, bonding force and water retention capacity, and constructability. In addition, the hydrophobic latex powder can make the mortar has good water resistance. Re-dispersible latex powder is mainly used in: interior and exterior wall putty powder, tile adhesive, tile jointing agent, dry powder interface agent, exterior insulation mortar, self-leveling mortar, repair mortar, decorative mortar, waterproof mortar and other dry-mixed mortar, the structure is binary copolymerization, ternary copolymerization of high molecular polymer.
 
2. Polycarboxylate superplasticizer
A superplasticizer for building materials, for mineral binder (ordinary cement, calcium chlorate cement, calcium sulfate), through the electrostatic repulsion and steric effect of the two together, the product is more traditional water reducing agent anti-flocculation ability is stronger, and the effect is more durable. As a new generation of water reducing agent, polycarboxylate water reducing agent has high water reducing rate, low dosage and high performance, small slump loss, good adaptability to cement, small shrinkage rate, beautiful entity structure, and can meet the construction of various special structures. At the same time, the price of polycarboxylate superplasticizer will also go down step by step, and it is more and more likely that the mixing station will use polycarboxylate superplasticizer in low-grade concrete.
 
3. Defoamer
Defoamer is a surfactant suitable for cement and gypsum-based dry-mixed mortar. It has the characteristics of easy dispersion, rapid defoaming, high stability, strong adaptability, chemical stability and low addition amount. The defoamer can defoam (eliminate) the microbubbles generated in the construction or production of building materials, so that the surface of the finished product is smooth, the internal structure is dense, and the product performance is improved. And make the product have excellent durability and shear stability and increase strength. Powder defoamer is more and more used in modern building materials. The defoaming agent can inhibit the formation of foam and destroy the formed foam in the mortar. Its mechanism is: the defoamer into the liquid film, reducing the viscosity of the liquid, the formation of a new low surface viscosity interface, so that the liquid film loss of elasticity, accelerate the liquid exudation process, and finally make the liquid film thin and rupture. At present, the defoamers used in mortar products are compounds composed of one or more additives on the basis of the main agent."
 

Key words:

Redispersible latex powder, polycarboxylate superplasticizer, defoamer