The effect of limestone powder on mechanical properties of Reactive Powder Concrete (RPC)

Reactive powder concrete (RPC) is a type of ultra-high performance concrete (UHPC) with a high cementitious materials content. Coarse aggregates are removed in RPCs and ultra-fine powder materials such as silica sand, silica fume and pozzolans are used to provide a homogeneous concrete with excellent microstructure. In this study, the effect of limestone powder on the physical and mechanical properties of reactive powder concrete has been investigated. Limestone powder was replaced with different percentages of silica sand, and compressive strength, flexural strength, shrinkage, and water absorption percentage of samples were measured at 7, 28, and 90 days of age. Experimental results showed that the 28-day compressive strength of this concrete was greater than 100 MPa and the physical and mechanical properties of the concrete were improved by increasing the amount of stone powder The mixture containing 54% replacement of limestone powder had the highest compressive strength and the lowest water absorption. Also, replacing silica sand with limestone powder increases shrinkage due to drying and reduces the Autogenous shrinkage of reactive powder concrete.