Abstract
Trial underwater concretes were prepared by mixing ultra high-fineness slag (Blaine area of around 14 000 cm2/g) with ordinary Portland cement (OPC). Strength development and segregation resistance properties of the concrete under the coexistence of some kinds of segregation controlling agents were studied for laboratory and concreting in site tests. As the results, the underwater concretes composed of the ultra high-fineness slag are found to be applicable to the actual use. The concrete's major features are (1) a good segregation-resistance property which leads to the reduction of the dosages of segragation controlling agents, (2) a good pumpability, (3) a high self-leveling property, and (4) good mechanical properties.
