Sulfoaluminate cement-based self-leveling mortar and preparation method thereof

Abstract

The invention provides sulfoaluminate cement-based self-leveling mortar and a preparation method thereof. a dry material for preparing the sulfoaluminate cement-based self-leveling mortar is preparedfrom the following raw materials in parts by weight: 10 to 20 parts of ordinary Portland cement, 15 to 25 parts of sulfoaluminate cement, 4 to 8 parts of natural gypsum, 35 to 50 parts of fine aggregate natural river sand, 10 to 25 parts of filler heavy calcium carbonate powder, 0.20 to 0.40 part of water reducing agent, 0.10 to 0.20 part of retarder, 0.05 to 0.02 part of early strength agent, 0.40 to 0.80 part of latex powder and 0.01 to 0.04 part of thickening agent. The sulfoaluminate cement-based self-leveling mortar provided by the invention has good working and mechanical properties suchas low cement-sand ratio, high early strength, high uniformity and high flowability, the cost is low, the preparation technology is simple, and one-day compressive strength is 16.0MPa or above.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a sulphoaluminate cement-based self-leveling mortar and a preparation method thereof. Background technique [0002] Cement-based self-leveling mortar, also known as self-leveling floor mortar, can be used as a structural material to improve ground defects and ground repairs. When in use, it has excellent fluidity after being mixed with water and can be poured by pumping. It can be automatically leveled to form a smooth surface after paving. Due to the excellent fluidity of cement-based self-leveling mortar, it can form a smooth plane under its own gravity, coupled with the characteristics of good mechanical strength in the early and late stages, and good interface adhesion, it can realize rapid maintenance construction and reduce construction strength. It has a good social economic benefits. Compared with organic floor materials such as epoxy resin, inorganic floor...

AI Technical Summary

Problems solved by technology

[0003] At present, the main application obstacles and key problems of cement-based self-leveling mortar are: although cement-based self-leveling mortar has received great attention and achieved some application effects, the current cement-based self-leveling mortar still has poor surface quality , Compatibility between admixtures and its adaptability to cementitious materials, as well as defects such as prolonged construction time caused by low early strength

In addition, using cellulose ether as the main thickener of self-leveling mortar, while improving the segregation and bleeding of the mortar, there are problems such as the introduction of air bubbles and a relatively large negative impact on the mechanical strength of the mortar.

[0004] Chinese patent CN102826814B discloses a method for cement-based self-leveling mortar. Among the cementitious materials used, the proportion of sulfoaluminate cement in the total cementitious material is relatively small, about 20-30%, which has a small increase in early strength, and The proportion of lime sand is relatively high, about 1.0-1.2, that is, the amount of cementitious material is relatively large, and the preparation cost is relatively high; Chinese patent CN102826814B discloses a preparation method of cement-based self-leveling mortar, and the cementitious material used is Rapid hardening sulphoaluminate cement and hemihydrate gypsum are used as auxiliary cementitious materials, but the cost of quartz sand used in this preparation material is about 5-10 times that of ordinary river sand, and single sulphoaluminate cement is used as the main cementitious system , there are disadvantages such as large heat release in the early stage of hydration and less strength increase in the later stage

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