Modified cement-based self-leveling mortar and preparation method and application thereof

Abstract

The invention relates to improved cement-based self-leveling mortar and a preparation method and application thereof. The improved cement-based self-leveling mortar comprises the following components in percentage by weight: 50%-70% of aggregate, 31%-40% of cement, 13%-15% of anhydrite, 5%-15% of ground calcium carbonate, 0.05%-0.3% of water-retaining agent, 0.05%-0.2% of carbonate, 0.4%-0.9% of retarder, 0.3%-0.9% of lignocellulose, 0.2%-0.3% of antifoaming agent, 0.6%-0.9% of water reducer and 1.5%-4.5% of pure acrylic emulsion powder. The invention has the advantages of simple preparation and application methods, good construction peaceability, good waterproofness, greatly reduced microcracks, high mechanical physics property, good self-leveling performance and impact resistance, and excellent flexibility; no cracking and shrinkage occur to constructed ground; and in addition, the invention can effectively solve the problems of complex site operation process, unstable mortar performance, environmental pollution and the like of the existing dual-component cement-based self-leveling mortar, thus the self-leveling mortar is a green building material because no toxic and harmful matter is contained.

Description

technical field [0001] The invention belongs to the field of building materials, in particular to a cement mortar, especially a modified cement-based self-leveling mortar, a preparation method and an application thereof. Background technique [0002] Cement-based self-leveling mortar is a kind of dry powder premixed mortar, which is widely used for leveling indoor floors of public buildings such as residences, hospitals, supermarkets, and light industrial floors. Cement-based self-leveling mortar has the characteristics of good fluidity, self-leveling, convenient construction and fast hardening in the new mixing state. The hardened cement-based self-leveling mortar has the characteristics of high compressive and flexural resistance, high bonding strength and good volume stability. Using cement-based self-leveling mortar to level the ground construction can greatly improve the construction efficiency and quality. [0003] However, the existing cement-based self-leveling mor...

AI Technical Summary

Problems solved by technology

[0005] 2) It is easy to cause dehydration of the thin-layer structure. On the one hand, due to the evaporation of free water, the dehydration of the self-leveling mortar thin-layer structure will cause drying and shrinkage, which will cause the mortar to crack, causing the mortar layer to leak and fall off; On the other hand, the self-leveling layer absorbs water, which makes the mortar lose water rapidly in the early stage

[0006] 3) When the cement-based self-leveling mortar does not have the waterproof function, after being affected by water erosion and temperature changes, the self-leveling layer is prone to thermal cracking, leakage, hollowing and shedding diseases

[0007] 4) It is easy to cause inconsistent deformation at the interface between the self-leveling layer and the base layer. The interface is hollow, and then cracks and falls off; on the other hand, due to the volume shrinkage of the self-leveling layer, the interface deformation between the two is inconsistent

[0008] 5) Chemical shrinkage is prone to occur. Since the volume of cement after hydration is smaller than the volume before the reaction, the total volume reduction is generally 7% to 9%. Due to partial shrinkage, it cannot be recovered.

Therefore, the chemical shrinkage caused by the cement hydration reaction will cause the volume change of the cement-based self-leveling mortar, which may lead to the generation of shrinkage cracks.