| 【文章摘要】 The effects of mineral powders on scaling, water absorption and internal deterioration of concretes are studied. Properties of a reference concrete produced with Portland cement are compared with corresponding mineral powder concretes. In the mineral powder concretes the Portland cement is replaced by 10 or 20 wt% by either limestone or quartz powder. Some mixes also contain a further addition of 10 and 20wt% of these powders to the Portland cement. Surface scaling and internal damage tests and a capillary suction test are performed on the concretes, to obtain a basic understanding of the freeze-thaw durability of the mineral powder concretes. The results suggest that the use of mineral powders itself does not have an effect on the freeze-thaw resistance, but the consequent binder reduction and loss of strength impairs durability. The loss of strength resulting from the replacement of the cement and the consequent reduction in the freeze-thaw durability might be compensated for by reducing the water/cement (w/c) ratio of the mineral powder concretes. This may be possible because the use of mineral powders increases the flow, that is, reduces the water demand of the test concretes. |