关键词: 糯米淀粉;氯氧镁胶凝材料;力学性能;耐水性;泛霜

Abstract: The influence of the modification of glutinous rice(GR)amylopectin on the properties of magnesium oxychloride cement(MOC)and the effects of the frost inhibition were studied.The hydration phase compositions,micromorphology and functional group bonding of the samples were characterized and analyzed by XRD, SEM and FT-IR, respectively.The results show that the addition of glutinous rice amylopectin is advantageous to formation of strength phase within the MOC system,the reactive functional groups of starch with MOC are chemically bonded or physical combination, the hydration phase formed crossover network and the micromorphology of samples are more compact.The optimal dosage of glutinous rice amylopectin(RGR)is 3% mass compared to magnesium oxide.Added 3% of raw glutinous rice amylopectin(GGR)into MOC,the 3 d,7 d and 28 d compressive strength relative to the blank sample increased by 46.78%, 32.65% and 29.49%, respectively, and 28 d softening coefficient is 0.81. Added 3% of gelatinized glutinous rice amylopectin into MOC, the 3 d, 7 d and 28 d compressive strength relative to the blank sample strength increased by 38.26%, 27.92% and 24.91%, respectively,and 28 d softening coefficient is 0.79.Compared to gelatinized glutinous rice amylopectin, the raw glutinous rice amylopectin have more obviously effect in the improving of performance to the MOC.

Key words: glutinous rice amylopectin;magnesium oxychloride cement material;mechanical property;water resistance;frost