Modification Of Magnesium Oxychloride Cement Composite And Its Application In Agricultural Big Canopy Frame

The magnesite resource is rich in oure country, many types of magnesite cementitious materials products are widely applied in many fields. Over the last decade, Modification of magnesium oxychloride cement application in agricultural big canopy frame has substantially growth, but because some of its own shortcomings such as poor water resistance, easy warpage and and so on,which limited its application in rainfall southern areas.In this paper, to overcome the defects in magnesium target material, we research the formulation and preparation process of magnesium material, focusing on the chemical modification of materials, development different types of special modifiers, add the activity of admixture and lightweight fill material, optimization of process conditions and with the ratio of means to improve the water resistance of materials and deformation properties; at the same time,we also studied its application in agricultural big canopy frame.combined with the Jiangxi hancheng Company's production of magnesite cementitious materials agricultural big canopy frame, we find the formulation and preparation process of magnesium material agricultural big canopy frame,study the reachtion of the magnesium material process and reaction mechanism.The results show that:the suitable preparation of magnesite binder paste MgO/MgCl2 molar ratio is 8 to 9, in this ratio, the strength of material come to the maximum, back to halogen is not obvious, but it is easily damaged in the early time. Add activity admixture and lightweight filler, the binder best MgO/MgCl2 magnesite molar ratio becomes 6 to 7; the appropriate ratio of magnesium based composite is: magnesium oxide 45.3%, magnesium chloride 24.2%, bamboo debris 5.4%,3.6% wood chips, ash 9%(of which the activity of magnesium oxide content of 60%, the magnesium chloride content of 44% of the total and effective); water should be minimized under the premise of ensuring the material forming. In the Modification of the materials:developed two kinds of different modifiers, which can make the materials'softening coefficient comes to 0.96 and 1.1, respectively; by adding modifiers to control curing conditions, control light filling volume, external stress, etc. the deformation of materials have been effectively controled.About Production process:pre-hydration treatment about 30% of the total mass of magnesium oxide can improve the water resistance of materials and reduce the deformation of materials, adequate mixing, the correct charging order, the appropriate curing conditions is necessary to obtain good performance of the material.