激发剂对复合胶凝材料微观结构和性能的影响

Effect of Activator on Microstructure and Properties of Composite Cementitious Materials

比较NaOH、NaOH+Na_(2)SiO_(3)溶液、NaOH+纳米二氧化硅溶液3种碱激发剂对碱活化磷渣基复合胶凝材料(AAPGF)性能的影响规律。采用扫描电子显微镜(SEM)、X射线衍射(XRD)仪和红外光谱测试(FTIR)等手段,研究了AAPGF的流动性、凝结时间、力学性能、水化产物形貌等变化。结果表明,不同的激发剂对胶凝材料的性能产生不同的影响。NaOH溶液作为激发剂,胶凝材料凝结时间最长。NaOH+Na_(2)SO_(3)溶液作为激发剂时,胶凝材料能够获得较高的强度,28 d抗压强度达到72.7 MPa。NaOH+纳米二氧化硅溶液作激发剂时,抗折强度最高,28 d抗折强度可达12.11 MPa。在3种激发剂激发下的水化产物均以水化硅酸钙(C-S-H)、水化硅铝酸钙(C-A-S-H)为主。NaOH+纳米二氧化硅(NS)溶液中NS不仅能够提供活性物质,而且能够产生微填充效应。

The effects of alkali activators NaOH,NaOH+Na_(2)SiO_(3) solution and NaOH+nano-silica solution on the properties of alkali-activated phosphorus slag based composite(AAPGF)were compared.The fluidity,setting time,mechanical properties and morphology of hydration products of AAPGF were studied by scanning electron microscopy(SEM),X-ray diffractometer(XRD)and infrared spectroscopy(FTIR).The results show that different activators have different effects on the properties of the materials.Specifically,NaOH solution as the activator has the longest coagulation time.When NaOH+Na_(2)SiO_(3) solution is used as the activator,high strength can be obtained,and the 28d compressive strength reaches 72.7 MPa.When NaOH+nano-silica solution is used as activator,the bending strength is the highest,and the bending strength of 28 d can reach 12.11 MPa.The hydration products stimulated by the three activators are mainly C-S-H and C-A-S-H.NS in NaOH+nano-silica solution can not only provide active substances but also produce micro-filling effect.