微波增强掺氧化石墨烯-氧化碳纤维磷酸镁水泥力学性能研究

Research on mechanical property of microwave-reinforced magnesium phosphate cement mixed with graphite oxide carbon fiber oxide

为补偿缓凝改性磷酸镁水泥(MPC)因凝结时间延长带来的力学性能损失,研究外掺氧化石墨烯(GO)、氧化碳纤维粉末(OCFP)对MPC力学性能的影响,确定最优掺量配比;在此基础上设计了4种微波养护方案,探究了其对MPC力学性能的影响,并采用XRD、FTIR分析其影响机理。结果表明,随氧化石墨烯、氧化碳纤维掺量的增加,MPC的力学性能先提高后降低,在最优掺量(0.4%OCFP及0.3%GO)时,MPC早期抗折、抗压强度分别提高约50%、35%;微波能促进MPC尤其是掺氧化石墨烯、氧化碳纤维MPC早期强度的提高,但强度提高率随着龄期的延长而减小,经最佳微波养护方案养护后,改性MPC早期抗折、抗压强度分别提高约45%、25%;GO及OCFP的掺入及微波作用仅提高了水化产物的产量及生成速率,未产生新的分子结构及化学键。

In order to compensate for the loss of mechanical properties caused by prolonged setting time of slow-setting modified MPC,this paper explored and analyzed the change rule of graphene oxide and carbon fiber oxide on the mechanical properties of MPC cement,and determined the optimal mixing ratio.On this basis,four microwave curing schemes were designed to explore their effects on the mechanical properties of MPC.Finally,XRD and FTIR techniques were used to analyze its influence mechanism.The results show that the mechanical properties of MPC increase first and then decrease with the increase of graphene oxide and carbon fiber oxide content.The optimum content(0.4%OCFP and 0.3%GO)can increase the early bending strength and compressive strength of MPC by about 50%and 35%,respectively.Microwave can promote the early strength of MPC,especially the MPC mixed with graphene oxide and carbon fiber oxide,but the strength increase rate will decrease with the increase of age.Appropriate amount of microwave can increase the early bending strength and compressive strength of modified MPC by about 45%and 25%,respectively.The addition of graphene oxide and carbon fiber oxide and the effect of microwave only increased the yield and formation rate of hydration products,but did not lead to the formation of new molecular structures and chemical bonds.