【作者】 习海平；

【导师】 黄少文；

【作者基本信息】 南昌大学 ， 材料工程， 2011， 硕士

【摘要】 我国有丰富的菱镁矿资源,因此菱镁胶凝材料的各类产品在我国很多领域获得广泛应用。近十几年来,菱镁复合材料在农用大棚支架中的应用日益增多,但因其自身存在耐水性差、易翘曲变形等缺陷,限制了其在我国多雨的南方地区的推广应用。本文以克服菱镁材料的性能缺陷为目标,研究了菱镁材料的基础配方和制备工艺,重点研究了材料的化学改性方法,通过研制不同种类的专用改性剂、添加活性掺合料和轻质填充料、优化工艺条件和配合比等手段,来改善材料的耐水性能和变形性能；同时,研究了利用改性菱镁复合材料制备农用大棚支架的工艺和方法,结合江西翰诚实业有限公司农用菱镁大棚支架生产线建设的实践,提出了工业化生产工艺方案和生产问题的解决办法；并探讨了菱镁材料的水化过程、水化产物及机理。研究表明：配制菱镁胶凝材料净浆的适宜MgO/MgCl2摩尔比为8～9,此时材料的强度最高,返卤现象不明显,但菱镁净浆水化早期膨胀值大,试体容易胀裂破坏。添加活性掺合料和轻质填充料后,菱镁胶结料的最佳MgO/MgCl2摩尔比为6～7；菱镁复合材料适宜的基础配合比为：氧化镁45.3%,氯化镁24.2%,竹屑5.4%,木屑3.6%,粉煤灰9%(其中氧化镁的活性含量以60%计,氯化镁的有效含量以44%计)；在保证材料成型的前提下材料的用水量应尽量减少。在材料的改性方面：研制出的多种改性剂对菱镁材料的耐水性有大幅度提高,其中的两种复合改性剂,使材料的半年软化系数分别达到0.96和1.1；通过添加改性剂、控制养护条件、控制轻质填料掺量、外加应力等手段,能够有效控制材料的变形。制作工艺方面：对氧化镁总质量的30%左右进行预水化处理能够有效提高材料的耐水性,减少材料的变形量,充分的搅拌、正确的加料顺序、合适的养护条件是材料取得优良性能的保障。更多还原

【Abstract】 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.更多还原