Study On Properties Of Magnesia Cementitious Material

Sulfur Magnesium Oxychloride cement(magnesium oxysulafte cement) has the advantages of light weight, good volume stability, high bending strength, fire resistance, thermal insulation properties. Although in flexural strength and compressive strength, the traditional sulfur magnesium oxychloride cement is worse than magnesium oxychloride cement, but in its water resistance, environmental protection and no rust for steel bars, sulfur magnesium oxychloride cement can be more effectively than magnesium oxychloride cement, especially in advantage of the production of decoration, decoration material methods.Therefore it is necessary to do further research on improving the performance of sulfur magnesium oxychloride cement.This experiment is based on the normal temperature of sulfur magnesium oxychloride cement’s basic mixture ratio test, finding the initial ratio of raw materials with excellent performance, at the same time,we did the test of magnesium oxychloride cement age, bending strength, compressive strength and a series of performance indicators, and the incorporation of different admixtures and mineral admixtures to improve its performance in this benchmark ratio of the magnesium oxychloride cement.In this benchmark ratio on magnesium oxychloride cement age, bending strength, compressive strength and a series of performance indicators, and the incorporation of different admixtures and mineral admixtures on the improved performance to do a detailed analysis, drawning that when MgO:MgSO4 is the same, with the increase of water, the initial setting time and the final setting time is extended, and when the amount of water is same, the initial setting time and setting time shortened with the increase of MgO:MgSO4.when MgO:MgSO4=3, 3-1-8 phase is the main hydration phase,and large numbers of MgSO4 doesn’t react;When MgO:MgSO4=5, 5-1-7 phase is the main hydration phase, which can increase the cement’s strength significantly;When MgO:MgSO4>5,Mg(OH)2 will constantly increased,mading the strength decreased.Through analyzing the modified magnesium cement concrete with gravel and sand and sand prepared by a certain percentage, founding that adding slag and fly ash to the magnesium in cement concrete, the strength of concrete with different degrees of increase, it also provides basis in future Production.We also observed the 517 phase crystal shape,which is main hardened produ cts,then used XRD test method analyzing sulfur magnesium oxychloride cement phase’s change rule,using SEM to analyze the different factors’ s inducing.Foun ding that the salt phase is a small needle like crystals, which made the salt ph ase has good density, and improved the water resistance of sulfur magnesium oxychloride cement. Compared with the slags, the influence of fly ash on magn esium cement gravel concrete strength is more obvious, the main reason is the ac tive components contained in fly ash points than slag as much, as activead mixtur e, fly ash and slag’s pozzolanic effect and latehydraulic characteristics, has a cert ain role in promoting for the magnesium cement sand and gravel concrete strengt h increase. In this paper, the study of sulfur magnesium oxychloride cement,we can be better promotes it in the future.