Experimental Study Of Compounding Modifying Magnesium Oxychloride Cement

In order to overcome the disadvantages of epoxy resin used in strengthening concrete structure, a new idea in which epoxy resin is replaced by magnesium 'oxychloride according to domestic conditions.The principle components, process and mechanism of hydration and hardening were reviewed. The fundamental reasons responsible for the poor water resistance of ordinary and existed modifying methods were introduced as well. Based on these and in the light of the successful applications of this kind cement in some fields, the feasibility of this cement to be used in fiber sheet strengthening concrete was discussed. On the basis of these, mobility, strength and water-resistance were decided as the main indexes in the first stage of the modifying experimental study.Behavior of single material modifying magnesium oxychloride cement was fist studied in an exploring test. Epoxy latex was used by the author in the first stage. Based on the understanding of the advantages and disadvantages of single admixture modifying, by means of concept design and chemical knowledge as well as the method of trial and error. Hybrid modifying experimental research was carried out. Relatively better mix ratio was obtained by this way. Test results showed that the properties of the hybrid modifying cement are much better than those of single modifying one.Some further research suggestions are proposed: (1) fine and micro of modified cement for further improving properties significantly and understanding the modifying mechanism; (2) special attention to the development of "supermolecule chemistry" for guiding cement modifying research; (3) hybrid fiber reinforced magnesium oxychloride cement for better ductility.