多元固废基胶凝材料水化性能研究

Research on hydration properties of multiple solid waste-based cementitious materials

以钢渣、矿渣和石膏为原料制备胶凝材料,测试了50%钢渣掺量试块的宏观强度和孔隙率,通过使用XRD、TG-DTG、水化热、SEM、ICP等测试方法对胶凝材料的水化性能进行了研究。结果表明,当m(钢渣)∶m(矿渣)∶m(石膏)=50∶40∶10时,试块强度较高。水化液相环境早期碱度低,加入石膏促进钢渣的水化,后期碱度上升,矿渣水化反应消耗钢渣水化产物氢氧化钙[Ca(OH)]生成钙矾石(AFt)。体系以AFt生成为驱动力,共同促进水化反应持续进行。在石膏的激发下,3 d龄期时试块内部有大量的水化产物生成,硬化浆体结构基本形成;28 d龄期时,AFt数量增加且尺寸明显增大,同时C-S-H凝胶填充于针棒状AFt空隙,使硬化浆体的结构更加致密。

Using steel slag,slag and gypsum as raw materials to prepare cementitious materials,the macroscopic strength and porosity of test blocks with 50% steel slag content were tested. The hydration properties of the cementitious materials were studied by using XRD,TG-DTG,heat of hydration,SEM,ICP and other test methods. The results show that when the mass ratio is m(steel slag)∶m(slag)∶m(gypsum)=50∶40∶10,the test block can obtain better strength. The alkalinity of the hydration liquid phase environment is low in the early stage,adding gypsum to promote the hydration of the steel slag,and increasing the alkalinity in the later stage.The hydration reaction of the mineral powder consumes the hydration product calcium hydroxide[Ca(OH)] of the steel slag to form ettringite(AFt). The system is driven by the generation of AFt to jointly promote the continuous hydration reaction. Under the excitation of gypsum,a large number of hydration products were formed inside the test block at 3 d age,and the hardened slurry structure was basically formed. At the age of 28 days,the number of AFt increased and the size increased significantly,and the C-S-H gel filled the needle-shaped AFt voids,making the structure of the hardened slurry more compact.