含有活性或惰性掺合料的复合胶凝材料硬化浆体的微观结构特征

MICROSTRUCTURAL CHARACTERISTICS OF COMPLEX BINDER PASTE CONTAINING ACTIVE OR INERT MINERAL ADMIXTURES

用压汞法测定了不同温度条件下养护的含有粉煤灰或石英粉的复合胶凝材料硬化浆体的孔隙率。用扫描电镜观察了硬化浆体的微观形貌,同时测定了各种组成的复合胶凝材料的净浆强度。常温水化初期,活性与惰性矿物掺合料都只具有物理填充的作用,硬化浆体的孔隙率和强度由矿物掺合料的掺量所决定。高温水化条件下粉煤灰的火山灰反应提前发生。随水化龄期延长,粉煤灰逐渐发生火山灰反应,使硬化浆体结构密实,其强度逐步提高。活性与惰性矿物掺合料对复合胶凝材料浆体结构与性能的影响的差异在水化后期逐渐显现。

Porosity of hardened complex binder pastes containing fly ash or quartz powder cured under different temperature regimes was determined using mercury intrusion porosimetry. The morphology of hardened pastes was investigated using a scanning electron microscope. The strength of pastes was measured. There was only a physical filling effect for both active and inert mineral admixtures during the initial hydration period. The porosity and strength of the pastes were controlled by the proportion of mineral admixtures. High hydration temperature advances the pozzolanic reaction of fly ash. With the prolongation of hydrating age the pozzolanic reaction of fly ash takes place, which densities the pastes and enhances the development of their strength. The difference of influence between active mineral admixture and inert ones on the structure and properties of complex binders emerges gradually in the later hydration period.