After adding redispersible latex powder into the mortar, the fold-compression ratio and tension-compression ratio of the mortar are greatly improved, which shows that the brittleness of the mortar is greatly reduced and the toughness is greatly improved, so that the crack resistance of the mortar got improved.
The redispersed latex powder loses water in the mortar to form a film, which not only fills the defects and pores in the cement stone, but also makes the cement hydration products and aggregates bond with each other to form an interpenetrating network of polymers. The elastic modulus of the mortar is lower than that of the mortar, so the brittleness of the mortar is reduced. The flexibility of the mortar increases the maximum deformation limit when the mortar is damaged, and can absorb the energy required for the expansion of defects and micro-cracks to the greatest extent, so that the mortar can withstand greater stress before failure. In addition, the polymer film has a self-stretching mechanism, and the polymer film has the function of a movable joint in the rigid skeleton formed in the mortar after cement hydration, which can ensure the elasticity and toughness of the rigid skeleton. The surface of the polymer film formed on the surface of the mortar particles has pores, and the surface of the pores is filled with mortar, so that the stress concentration is reduced, and it will relax without damage under the action of external force. Improves the flexibility and elasticity of the mortar.