Influence of mixing method, speed and duration on the fresh and hardened properties of Reactive Powder Concrete

Production methodology of Reactive Powder Concrete (RPC) is not clearly established yet, as several parameters have a varied influence on the resulting fresh and hardened properties of RPC. Even for the same composition, the fresh and hardened properties differ significantly by changing mixing method, mixing speed and mixing time/duration. The present investigation is an attempt to study the effect of mixing method, speed and duration, on the fresh and hardened properties of RPC. The study also deals with the microstructure investigation of RPC mixes. Results indicate that improved mixing techniques prove beneficial in enhancing fresh and hardened properties of RPC. Mixing speed and duration also have significant effect on the fresh and hardened properties of RPC. Higher mixing speed and longer mixing duration decreases flow and strength characteristics of RPC. Microstructure analysis reveals that higher mixing speed and longer mixing duration increases percentage of pores in RPC, leading to reduced fresh and hardened properties.