Modified magnesium cement light wallboard

Abstract

The invention provides a modified magnesium cement light wallboard. The modified magnesium cement light wallboard is composed of a foaming agent and the following components in parts by weight: 100 parts of magnesium oxide, 5-40 parts of fly ash and / or expanded perlite and polystyrene foam plastic light fillers, 60-80 parts of a sulfur-magnesium-phosphorus blending solution with the baume degree of 20-28 degrees, wherein the sulfur-magnesium-phosphorus blending solution is composed of the following components in parts by weight: 1 part of 50% sulfuric acid, 0.5 part of magnesium sulfate heptahydrate and 0.001 part of 50% phosphoric acid; and the volume ratio of the air bubble volume of the foaming agent to the total volume of the components is (4-5.8) to 1. According to the modified magnesium cement light wallboard, the sulfur-magnesium-phosphorus blending solution is used for replacing a magnesium chloride solution in the prior art, and magnesium chloride with strong activity and poor stability is removed; the technical problem that the quality of a magnesium cement wallboard is difficult to control is basically improved; and the defects, which are difficult to solve for a long period, that the magnesium cement wallboard has efflorscence halogenation and warping deformation, and corrodes a metal components, caused by chloridions are overcome.

Description

technical field [0001] The invention belongs to building materials, in particular to a modified magnesium cement lightweight wallboard. Background technique [0002] Magnesium cement wallboard is a kind of air-hardening cementitious material obtained by two-component mixing of activated magnesium oxide and industrial magnesium chloride solution. It has the superior properties of high early strength, low alkalinity and high flexural strength at room temperature. Magnesium cement Also commonly known as magnesium oxychloride cement. [0003] However, for a long time, magnesium cement products have the disadvantages of moisture absorption and brine return, which are still difficult to overcome. One is poor water resistance. The hydrate of magnesium cement is hydrophilic, and water can destabilize its crystal structure and eventually disintegrate. Use in wet or rainy environments. Second, brine reversion and frosting. Brine reversion means that water droplets or viscous water d...

AI Technical Summary

Problems solved by technology

Third, warping and deformation. Magnesium cement products release high heat during the hardening process. The temperature in the center of the reaction system can reach 140 degrees Celsius: in summer it may exceed 150 degrees Celsius: it is 3-3 degrees Celsius of ordinary Portland cement. 4 times. Due to the fast setting time of magnesium cement, the heat release is large, and thermal expansion causes product warping and deformation. Large-volume magnesium cement products often have microcracks, which slowly expand and deepen, resulting in product fragmentation

[0004] In response to the above problems, various efforts have been made, including the study of various additives, the selection of large molecular weight organic polymers, etc., in order to improve the reactivity of magnesium oxide and magnesium chloride, but failed to solve the problem fundamentally.