Study On System And Properties Of Magnesium-based Building Wall Thermal Insulation And Fireproofing Material

With the constantly rising of urbanization construction level, China has gradually became a country of huge building energy consumption. Wall thermal insulation technology is an effective way to reducing building energy consumption, it can not only meet the national policy of energy conservation and emissions reduction, but also improve living environment. Low grade magnesite has rarely been used for a long time, random stacking is a kind of phenomenon that waste resources and pollute the environment. Using light burned magnesium oxide made with low-grade magnesite and industrial by-product magnesium chloride as main raw materials, this paper made a kind of magnesium-based wall insulation material.Content of active magnesium oxide is a very important nature of light burned magnesium oxide, it determines the mix proportion of light burned magnesium oxide and magnesium chloride. This paper used hydrothermal synthesis method to test the content of active magnesium oxide from a sample, the estimated value was 39.12%, error of the two sets was only 0.46%, the means was easy and convenient. Content of active magnesium oxide will decline after placed in the air for a long time under normal circumstances, calcining the placed light burned magnesium at a certain temperature could increase content of active magnesium oxide. This paper calcined a placed 28.06% light burned magnesium oxide specimen at 750℃ for 1.5h by muffle furnace, the content of active magnesium oxide then reached to 68.85% and increase by 145.37% compare with before.A kind of water-resistant magnesium oxychloride cement(MOC) were made by fly ash、phosphoric acid、aluminum sulfate、organosilicon water-proofing agent and low-grade light burned magnesium oxide contains 34.91% active magnesium oxide. Crystal powder XRD analysis and fracture surface SEM analysis were applied to discuss the materials’ water-tolerant mechanism.The results showed that the improved magnesia materials had fine water resistance, soft coefficient raised from 0.76 to 0.98.A kind of magnesium oxychloride cement(MOC) based wall material was made with polypropylene fibre 、 waste ceramics 、 industrial magnesium chloride and low-grade light burned magnesium oxide that contains 39.12% active magnesium oxide has been researched in this paper. Orthogonal test was applied to find the best mix ratio; besides, the effect of fiber and ceramic waste on dry shrinkage of MOC was discussed, the results show that fibre and ceramics could reinforce and toughen magnesium oxychloride cement and play the role of framework. The products’ 28 d drying shrinkage is only 0.03%.Regression analysis of experimental data by Origin software was used in this paper, the relationship between EPS particles amount and apparent density, strength and thermal conductivity was quantificated in the form of equation. Break mechanism of magnesia cement based EPS particles lightweight aggregate concrete was analyzed, it was considerd that the strength reduction speed gradually became gradual was because the leading factor of strength reduction had became to mixing uniformity of EPS particles and cement paste from amount of hardened magnesium oxychloride cement. A new kind of two-sided turnover heat preservation mould was designed in this paper, it could make magnesia cement stone and EPS particles combine more uniformly and closely, thus the thermal insulation block’s safety performance could be enhanced. The magnesium-based building wall thermal insulation system was preliminarily designed in this paper and the structural map of magnesium-based EPS particles thermal insulation board thin plaster system was drawed. Figure 19, table 11, reference 57.