Some Factors Influencing Properties Of Modified Magnesium Oxychloride Cement And Its Modifying Mechanism

In order to overcome the disadvantages of low lightfastness and heat-resistance as well as poor fire-resistance of epoxy resin which is largely used in fiber reinforced polymer (FRP) strengthening concrete structure, a new idea to replace expensive epoxy resin with magnesium oxychloride was proposed with a reference to the better properties of Fiber Reinforced Magnesium Oxychloride Cement Inorganic Compsoite (FRIM)The principle components,process and mechanism of hydration and hardening of Magnesium Oxychloride Cement were reviewed. Base on the understanding of the advantages and disadvantages of singly inorganic material modifying magnesium xoychloride and by means of concept design and research, The most important properties, a hybrid modifying program was set up, strength and water-resistance were chosen as the evaluation indexes. The proper formula of magnesium oxychloride cement was determined and the best formula of inorganic modifying materials, including the phosphoric acid, ferric phosphate, silicon powder and flyash was chosen as well. Test results showed that the decrease of strength caused by using phosphoric acid can be compensated by using both silicon powder and phosphoric acid. Great improve the water-resistance of magnesium oxychloride cement was obtained by adding durafiber. In order to improve the water-resistance and brittleness, further epoxy, SAE,SBR and EVA of polymer emulsions were employed separately for modifying magnesium oxychloride cement. The practicing conditions with a special reference to temperature of polymer emulsion modified magnesium oxychloride cement were discussed.Some further research directions are suggested: in order to increase the interfacial adhesive strength of magnesium oxychloride cement and fiber as well as concrete. The coupling agent are suggested to be used for improving interfacial mechanical performance. Waterproof material as a coat over magnesium oxychloride cement is expected to improve the penetrating-resistance and water-resistance of magnesium oxychloride cement noticeably...