Characteristics of bleeding, freeze-thaw resistance and watertightness of concrete with ferro-nickel slag fine aggregates
Togawa Kazuo; Shoya Masami; Kokubu Katsuro
Abstract:Many reports have been published on various properties of concrete with ferro-nickel slag fine aggregates, and it has been pointed out that the concrete with such aggregate showed the nearly same strength as that of normal concrete. A total of five ferro-nickel slag fine aggregates were examined in this study. The experiments were conducted by fixing the volumetric mixture ratio of slag 50%, except crushed air granulated slag used for single fine aggregates, to investigate the efficiency of chemical admixtures and the water demand in the ferro-nickel slag concrete as compared with those of natural sand concrete. In addition, the bleeding properties of those concretes were fully investigated. The reduction of unit water content, by applying a high range water reducer, could be expected to the same degree as that of normal concrete, which also resulted in the decrease of bleeding. The additions of blastfurnace slag, silica fume and lime stone powder pronouncedly improved the compressive strength and the bleeding of ferro-nickel slag concrete. And then, the freeze-thaw resistance was improved by the addition of lime stone powder, but hardly improved by the addition of silica fume. It can be considered that the watertightness of ferro-nickel slag concretes is the same as that of natural sand concrete. Key Words:ferro-nickel slag aggregate, air-entraining water reducer, high range water reducer, blast furnace slag, silica fume, lime stone powder, bleeding, freeze-thaw resistance, watertightness