Influence of Ultra-Fine Particle-Type on Properties of Very High-Strength Concrete

Very-high strength concrete (>100 MPa) has been developed using different types of ultra-fine particles: silica fume, ground granulated blast-furnace slag, metakaolin, and cristobalite. The effect of the type of ultra-fine particle on some engineering properties of concrete has been investigated: compressive strength, loss of workability and plastic shrinkage. The highest level of strength (120 MPa) was obtained using either 20% slag, or 10% metakaolin, in addition to cement. The workability was maintained for one hour when slag or cristobalite were present in the mixture. The tests undertaken on plastic shrinkage pointed out that very-high strength concrete developed high plastic shrinkage, specially when pozzolans were used. The use of slag does not affect the plastic shrinkage.