氯氧镁水泥结构胶研制及界面高温性能研究

Development of magnesium oxychloride cement structural adhesive and research on high temperature performance of interface

首先对氯氧镁水泥的配比进行优化设计,通过考察改性氯氧镁水泥的力学性能、耐水性能和耐高温性能,辅助微观测试手段进行分析,从而确定氯氧镁水泥的最优配比,结果显示:当采用MgO/MgCl_(2)/H_(2)O摩尔比为9∶1∶10.9,氯氧镁水泥胶的力学性能最优;当羟基乙酸掺量为2%时,软化系数提高到0.88,明显改善氯氧镁水泥的耐水性能,能够满足加固工程需要;加入2%的硼酸镁晶须能够有效降低体积收缩率,提高抗压强度;然后对25~500℃高温处理后的氯氧镁水泥作为胶黏剂的界面黏结性能进行单面剪切试验,结果表明:25℃下氯氧镁水泥胶的界面黏结强度比环氧树脂为胶黏剂低10%,当温度升高至200℃时,界面黏结强度仍为25℃下的84.06%,300℃黏结强度下降为25℃的68.20%。

Firstly,the optimal design of the ratio of magnesium oxychloride cement is carried out,and the optimal ratio of magnesium oxychloride cement is determined by examining the mechanical properties,water resistance and high tem⁃perature resistance of modified magnesium oxychloride cement,and analyzing with the aid of microscopic testing meth⁃ods,the results show as follows:when the molar ratio of MgO/MgCl_(2)/H_(2)O is 9∶1∶10.9,the mechanical properties of mag⁃nesium oxychloride cement glue are optimal;when the content of glycolic acid is 2%,the softening coefficient increases to 0.88,which obviously improves the chlorine;The water resistance of magnesia cement can meet the needs of reinforce⁃ment projects;adding 2%magnesium borate whiskers can effectively reduce the volume shrinkage rate and improve the compressive strength.Then the magnesium oxychloride cement treated at 25℃to 500℃high temperature can be used as an adhesive.And the single-sided shear test was carried out on the interface bonding performance of the adhesive.The results show that the interface bonding strength of magnesium oxychloride cement adhesive at 25℃was 10%lower than that of epoxy resin adhesive.When the temperature increases to 200℃,the bond strength of the interfate is still 84.06%at 25℃,and the bond strength at 300℃drops to 68.20%at 25℃.