Effect of Rubber Powder on Flexibility of Cement-based Materials


Release time:

2021-09-27

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Redispersible latex powder

Effect of Rubber Powder on Flexibility of Cement-based Materials

Redispersible latex powder can improve the flexural strength, adhesion strength and other properties of mortar, because it can form a polymer film on the surface of the mortar particles, the surface of the film has pores, and the surface of the pores is filled with mortar, so that the stress concentration is reduced, and under the action of external force will produce relaxation without destruction. In addition, the mortar after hydration of cement to form a rigid skeleton, and the polymer in the skeleton has the function of a movable joint, similar to the human body's tissue, the film formed by the polymer can be likened to joints and ligaments, thus ensuring the elasticity and toughness of the rigid skeleton.


In the polymer modified cement mortar system, the continuous and complete polymer film is intertwined with the cement paste and sand particles, making the whole mortar more fine, and at the same time, the whole becomes an elastic network by filling the capillary and the cavity. Therefore, the polymer film can effectively transmit pressure and elastic tension. The polymer film can bridge the shrinkage cracks at the polymer-mortar interface, heal the shrinkage cracks, and improve the sealing and cohesive strength of the mortar. The presence of highly flexible and highly elastic polymer regions therein improves the flexibility and elasticity of the mortar, providing cohesion and dynamic behavior for the rigid skeleton. When an external force is applied, the microcrack propagation process is delayed due to the improvement of flexibility and elasticity until a higher stress is reached. Interwoven polymer regions also act as a barrier to the coalescence of microfractures into through-fractures. Therefore, the redispersible emulsion powder increases the failure stress and failure strain of the material.


Key words:

Redispersible latex powder