外掺氧化镁膨胀剂对水泥净浆流变特性及胶砂强度的影响

研究了氧化镁膨胀剂在不同掺量下对水泥浆体流变特性和胶砂强度的影响规律。研究结果表明:外掺氧化镁膨胀剂,会降低水泥浆体流动度,增大浆体的剪切粘度,提高浆体的屈服应力和塑性粘度;掺氧化镁膨胀剂胶砂3d龄期的抗压强度稍低于不掺氧化镁膨胀剂的胶砂,7d、28d时抗压强度高于不掺氧化镁膨胀剂的胶砂,当掺量为6%时,抗压强度较不掺氧化镁膨胀剂的胶砂增加了10%左右;3d、7d龄期时掺氧化镁膨胀剂组的胶砂抗折强度要低于不掺氧化镁膨胀剂组,而28d龄期抗折强度明显高于不掺氧化镁膨胀剂组。

Effect of Magnesium Oxide Expansive Agent on Rheological Properties of Cement Paste and Strength of Cement Mortar

In this paper,the effect of magnesium oxide expansive agent content on the rheological properties of cement paste and the strength of mortar was studied.The results showed that the incorporation of magnesium oxide expansive agent reduced the fluidity of cement slurry and increased the shear viscosity of slurry.The incorporation of magnesium oxide expansive agent increased the yield stress of slurry and improved the plastic viscosity of the slurry.The compressive strength of the mortar mixed with magnesium oxide expansive agents was lower than that of reference group at the age of 3 days and higher at the age of 7 days and 28 days.When the content of magnesium oxide expansive agents was 6％,the compressive strength was about 10％ higher than that of the reference group.The flexural strength of the mortar mixed with magnesium oxide expansive agents was lower than of the reference group at the age of 3 days and 7 days and significandy higher than that at the age of 28 days.