Effect Of RPC Compositions On: Compressive Strength and Absorption

Concrete is a critical material for the construction of infrastructure facilities throughout the world. A new material known as Reactive Powder Concrete (RPC), or sometimes called Ultra-High Performance Concrete (UHPC), is becoming available that differs significantly from traditional concretes. It is an ultra high strength and high ductility composite material with advanced mechanical properties. It consists of special concrete whose microstructure is optimized by precise gradation of all particles in the mix to yield maximum density.\ud Different RPC mixes in the experimental investigation of the present study the mechanical properties of RPC including compressive strength, density and absorption.\ud The main variables used in the production of the different RPC mixes of the present research are three, namely, type of pozzolanic admixture (metakaolin, micro silica, and silica fume), type of fibers (steel and polypropylene fibers) and volume fraction of fibers (1.0,1.5, and 2.0)%.\ud The experimental results indicated that RPC mixes with silica fume gave the highest values of compressive strength and density and lowest value of absorption in comparison with RPC using micro silica or metakaolin where metakaolin was the third in such comparisons. However the RPC mixes used in the present investigation gave group compressive strength ranging between 164 -195 MPa.\ud It was also found that the use of steel fibers with high volume fraction (2%) in an RPC mix increases the compressive strength by 8% and density of the concrete by 2.5% and reduces its absorption by 13%, unlike an RPC mix using polypropylene fibers of lesser volume fraction.\u