互穿网络结构水泥基复合材料的性能和机理研究

Study on properties and mechanism of interpenetrating network structure cementitious composites

以过硫酸铵和N,N,N′,N′-四甲基乙二胺为氧化还原引发体系,N,N′-亚甲基双丙烯酰胺为交联剂引发丙烯酰胺在水泥净浆体系中进行常温原位交联聚合,制备了互穿网络结构的水泥基复合材料。利用傅里叶红外光光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)和水泥水化热测试仪对该水泥基复合材料的结构形成机理进行研究,并进行抗压、抗折强度和凝结时间测试。结果表明:复合材料在形成初期,聚合物快速聚合形成网络结构,缩短了复合材料的凝结时间,并使复合材料的抗折强度显著增加。聚合物形成的网络结构对水泥颗粒的包裹,延缓了水泥早期的水化进程,抑制水泥水化矿物的早期生成,但不改变水泥水化产物的种类。互穿网络结构高性能水泥基复合材料具有快速凝结、韧性好的特点,可在修补工程及喷射混凝土施工中使用。

The cement-based composites with interpenetrating network structure was prepared through in-situ crosslinking polymerization of acrylamide in the cement slurry system at room temperature,which using ammonium persulfate(APS)and N,N,N′,N′-tetramethylethylenediamine(TMEDA)as the redox initiator,and N,N′-methylene biacrylamide(MBA)as the crosslinking agent.The mechanism of this composite material were studied by Fourier infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscopy(SEM)and cement hydration heat tester,and its compressive strength,flexural strength and setting time were tested.Result show that in the early stage of composite formation,the initial setting time of composites was shortened while significantly increasing the flexural strength.The cement particles was wrapped by the polymer forms a network structure,thus inhibiting the early generation of cement hydration minerals,but not changing the type of cement hydration products.The high-performance cement-based composites material with interpenetrating network structure has the characteristics of rapid condensation and better toughness,and can be used in repair engineering and shotcrete.