摘要
1 he composition and structure of the interfacial zone be-tween aggregate and Portland slag cement paste as well as the orienta-tion coefficient of portlandite (ICH) have been studied by means of XRD and SEM. The results show that the main components in the in-terfacial zone are C-S-H gel, portlandite and AFt as well as unhy-drated clinder particles. Compared with Portland cement, there are more C-S-H gel and less portlandite in the zone and the portlandite crystallizes badly with lower ICH in a narrower region . After adding 5. 0% silica fume to the cement , the orientation of portlandite in the zone disappears; after 90d, the bond strength between #425 Portland slag cement paste and aggregate approximately attains that between # 525 Portland ciment paste and aggregate.
1 he composition and structure of the interfacial zone be-tween aggregate and Portland slag cement paste as well as the orienta-tion coefficient of portlandite (ICH) have been studied by means of XRD and SEM. The results show that the main components in the in-terfacial zone are C-S-H gel, portlandite and AFt as well as unhy-drated clinder particles. Compared with Portland cement, there are more C-S-H gel and less portlandite in the zone and the portlandite crystallizes badly with lower ICH in a narrower region . After adding 5. 0% silica fume to the cement , the orientation of portlandite in the zone disappears; after 90d, the bond strength between #425 Portland slag cement paste and aggregate approximately attains that between # 525 Portland ciment paste and aggregate.
