氧化石墨烯泡沫混凝土性能及作用机理研究

Study on the properties and action mechanism of graphene oxide foamed concrete

采用氧化石墨烯作为泡沫混凝土的增强相,研究了氧化石墨烯泡沫混凝土的水化进程、微观形貌及物理性能,并通过X射线衍射分析、同步热分析、扫描电镜等测试方法分析氧化石墨烯对泡沫混凝土的作用机理。结果表明:与未掺加氧化石墨烯的空白组对比,氧化石墨烯掺量为0.03%时,泡沫混凝土抗压强度提高了16.3%;当掺量为0.02%时,其导热系数降低了2.7%;氧化石墨烯不会使结构产生新的水化产物,且其对泡沫混凝土主要水化产物含量及水化反应速率影响不显著,即氧化石墨烯对泡沫混凝土的水化进程无明显影响。因此,氧化石墨烯可以吸附胶凝材料颗粒和水,提供水化反应的生长点,同时,其可以减缓裂缝扩展,即氧化石墨烯在泡沫混凝土中主要起到模板和阻裂作用,从而改善了泡沫混凝土的性能。

Graphene oxide is used as the reinforcement phase of foamed concrete.The hydration process,microstructure and physical properties of graphene oxide foamed concrete are studied through experiments with several test methods such as XRD,TG-DSC and SEM so as to analyze the mechanism of the effect of graphene oxide on foamed concrete.The results show that when graphene oxide content is 0.03%,the compressive strength of foamed concrete increases by 16.3%compared with the blank control group without graphene oxide;when graphene oxide content is 0.02%,the thermal conductivity decreases by 2.7%.The addition of graphene oxide will not produce new hydration products,and it has no significant effect on the content of the main hydration products and hydration rate of the foamed concrete.In other words,graphene oxide has no obvious effect on the hydration process of the foamed concrete.Graphene oxide can adsorb cementitious material particles and water,providing the growth point of hydration reaction,and at the same time graphene oxide also slows down the propagation of cracks.That is,graphene oxide plays a role of template and crack resistance in foamed concrete,thus improving the performance of foamed concrete.