NaOH激发粉煤灰基胶凝材料的水化产物

以粉煤灰为原料，NaOH为激发剂，制备出高抗压强度的粉煤灰基碱激发胶凝材料，研究养护条件对粉煤灰基碱激发胶凝材料抗压强度的影响。用x射线衍射分析不同龄期粉煤灰基碱激发胶凝材料的矿物组成，并用带能谱分析的扫描电镜观察不同龄期材料的微观形貌和区域元素组成。结果表明：蒸汽养护可以显著提高材料的抗压强度：粉煤灰中的玻璃相参加材料的水化反应，莫来石、石英等晶相则为惰性物质，不参加反应：在水化过程早期，粉煤灰基碱激发胶凝材料的气孔内会形成钠系菱沸石的前驱体，蒸汽养护1d后长大为表面呈十字交叉状的1pm左右颗粒，随着时间延长，这些颗粒可长至5μm左右，交错重叠充满整个气孔内壁，形成致密的空间网状结构，使材料强度得到提高。

Hydration Products of Fly Ash Based Cementing Material Activated By NaOH

A fly-ash based alkali-activated cementing material (FACM) was prepared by using fly ash as a raw material and NaOH as an activating agent. The effect of curing conditions on the compression strength of FACM was investigated. The mineral composition of FACM at different ages was analyzed by X-ray diffracion. The microstructure and element composition of hydration products of this material at different ages were characterized by scanning electron microscope with X-ray energy dispersive technique. The results show that the compression strength of FACM is enhanced under steam curing condition. The glass phase in fly ash participated in the hydration reaction, but the inert phases such as mullite, quartz, magnetite, etc. did not be involved in. Zeolite precursor formed in the pore of FACM in the early hydration process, and the particle size grew up to 1 μm with the cross-shape after cured for 1 d. With the prolonging of curing time, the particle size could be 5 μm. With the time prolonged, the particles overlapped with each other, filled in the entire pore and formed the compact reticulate structure, favoring the improvement of the compression strength of materials.