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

• Published in: Construction & building materials 2017-06, Vol.141, p.271-288
• Main Authors: Hiremath, Parameshwar N., Yaragal, Subhash C.
• Format: Article
• Language: English
• Subjects: Analysis; Methods; Microstructure; Mixing duration; Mixing method; Mixing speed; Powders (Particulate matter); Reactive Powder Concrete
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2017.03.009

•A new four stage mixing method of producing RPC is proposed.•The optimum mixing speed, for pan mixer is suggested, for producing RPC.•The concept of change point to identify flowability of RPC mixes is introduced.•An attempt to produce RPC using indigenous materials and conventional equipment’s. 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.