机械和化学激发对无水泥免烧砖性能的影响

Effect of mechanical and chemical activator on performance of no-cement unburned brick

主要研究了用循环流化床粉煤灰、烟气脱硫石膏和磨细高炉矿渣混合制备无水泥FGS胶凝材料,并由此制备免烧砖。通过机械和化学活化激发FGS胶凝材料的火山灰活性。机械激发即改变成型压力分别为20、40、60、80和100 MPa;化学激发即通过加入激发剂——水玻璃和生石灰。测试免烧砖的3、7、14、28 d抗压强度,激发剂的加入使得免烧砖的抗压强度能够达到40～50 MPa。微观分析表明,FGS胶凝材料的主要水化产物为钙矾石、N-A-S-H和C-A-S-H凝胶,其中凝胶对强度的贡献更突出。

This study presents the various low energy no-cement unburned bricks made with FGS binder which was fabricated by purely combining three industrial by-products of circulating fluidized bed combustion fly ash,flue gas desulfurization gypsum,and ground granulated blast furnace slag. Pozzolanic reactivity of FGS binder were activated by mechanical and chemical activation. FGS binder was activated mechanically by molding at 20,40,60,80 and 100 MPa. And FGS binder was chemically activated using two activators:sodium silicate and limestone. Tests were carried out to characterize the mechanical behavior of unburned bricks at 3,7,14 and 28 days. The addition of activator allows the compressive strength to reach 40 to 50 MPa. Microscopic analysis showed that the main hydration products of FGS binder were ettringite,N-A-S-H and C-A-S-H gels, and the contribution of gel to strength was more prominent.