The effect of silica fume and blast furnace slag on the properties of reactive powder concrete

Reactive powder concrete (RPC) is a developing composite material that will allow the concrete industry to optimize material use, generate economic benefits, and build structures that are strong, durable, and sensitive to environment. Reactive Powder Concrete (RPC) is a relatively new cementitious material. Its main features include a high percentage ingredient of Portland cement, very low water-to- cement ratio. RPC is characterized by ultra-high performance in mechanical properties, particularly in compressive strength; and this would be of tremendous interest to construction practitioners. The main goal of this study is to produce RPC from silica fume (SF) and ground granulated blast furnace slag (GGBFS) with inclusion of steel fiber. The experimental program was prepared as a mixture of ten trials using SD and YFC content. In the mixtures, silica fume contents of 0%, 15% and 30% by weight of cement and 0%, 15% and 30% of YFC contents by weight of cement are used. In this study, in which RPB production was investigated using commercially available materials, it was determined that 90-day samples successfully reached 107.9 MPa minimum compressive strength under standard conditions and 25°C curing temperature. The highest compressive strength in RPB concretes in 90 days was obtained with 30% SD and 30% YFC and reached 117.2 MPa. In addition, it was observed that the addition of SD had positive effects on the compressive strength and split-tensile strength in the early and later ages of the RPB, while YFC had a negative effect on the mechanical properties of the RPB. However, the incorporation of YFC at later ages led to improved mechanical properties. In addition, cement substitution with SF and YFC was found to have a positive effect on the porosity and water absorption of the RPB. KEYWORDS:Reactive powder concrete, RPC, silica fume, ground granulated blast furnace slag, porosity, water absorption