偏高岭土/P(AA-co-AM)复合型高吸水性树脂对水泥砂浆性能的影响及机理研究

Effect of metakaolin/P(AA-co-AM)composite super absorbent polymer on properties of cement mortar

为了探究标准养护环境和自然环境下,有机/无机复合型高吸水树脂(Super absorbent polymer,SAP)不同掺量对水泥基材料性能的影响,采用自主研发的SAP制备改性水泥砂浆,并对其在标准养护环境和自然环境下的工作性能、力学性能、收缩性能和耐久性能进行评价,通过扫描电子显微镜和X射线衍射仪对其微观改性机理进行探究.结果表明:复合型SAP的掺入会降低水泥砂浆的流动度,掺量越高越显著;在两种环境下,复合型SAP均可提高水泥砂浆的力学性能,降低水泥砂浆的收缩率,同时对水泥砂浆的抗冻性有积极作用.微观测试发现,复合型SAP释水后在其孔隙壁上形成了一层无机/有机薄膜,水泥砂浆中的AFt、Ca(OH)_(2)和C-S-H凝胶增多,水泥水化程度更高.

In order to explore the influence of different organic/inorganic compound Super Absorbent Polymer(SAP)content on the properties of cement-based materials in standard curing environment and natural environment,cement mortar is prepared by self-developed compound SAP,and the workability,mechanical properties,shrinkage properties and durability are evaluated in standard curing environment and natural environment,respectively.In addition,the modified mechanism is explored by scanning electron microscope and X-ray diffractometer.The results show that compound SAP has a negative effect on the fluidity of cement mortar,and the higher the content,the greater influence.In both environments,compound SAP can improve the mechanical properties of cement mortar,reduce the shrinkage rate of cement mortar.Moreover,it also has a positive effect on the freezing resistance of cement mortar.The microscopic tests show that a layer of inorganic/organic film is formed on the pore wall of compound SAP after water release.The content of AFt,Ca(OH),and C-S-H gel in cement mortar is increased,and the hydration degree of cement is higher.