Reactive powder concrete1. IntroductionReactive Powder Concrete (RPC) was developed by P. Richard and M. Cheyrezy and was first produced in the Bouygues laboratory in France2 in the early 1990s. In July 1997, the Sherbrooke bridge, at Quebec, Canada3, became the first structure in the world built entirely from reactive powder concrete. Due to its extremely low permeability, it is also used for nuclear waste containment in Europe4. Reactive Powder Concrete (RPC) is essentially a specialty concrete whose microstructure is optimized by precise grading of all constituent particles to produce maximum possible density. This results in a composite with extremely high strength (compressive strength ranging from 200 MPa to 800 MPa) and also high ductility (thanks to the addition of steel fibers) as well as improved mechanical and physical properties (low permeability, etc.). RPC also makes extensive use of the pozzolanic properties of highly refined silica pozzolans and optimization of Portland cement chemistry to produce the strongest hydrates1 without the use of aggregates of course. RPC is therefore an ultra high strength concrete (UHSC).2. Composition of Reactive Powder Concrete RPC is essentially composed of very fine powders: • Cement • Sand • Quartz powder • Silica Pozzolan (Microsilica, Silica fume etc.) • Steel fibers (optional) • Super plasticizer The objective is to obtain a very dense matrix using extremely low water/binder (p/b) ratio (0.13-0.24) and optimizing the granular packing of dry fine powders. The resulting compactness gives the RPC ultra-high strength and durability6. Table 1 presents the different components of the RPC and their selection parameters.3. Reactions in progress • Hydration of cement2C3S + 6H ...... middle of paper ......ngs like stadium roofs, long bridge spans and anything that requires additional safety or security like structures explosion resistant• Its low permeability and high strength make it ideal for the storage of nuclear waste.8. Disadvantages • The constituents are expensive, which limits its use. • There is no appropriate code standardizing mixing9. References1. Richard P and Cheyrezy M, “Composition of reactive powder concrete”, Cement and Concrete Research, Vol. 25, no. 7, (1995), pages 1501 to 1511.2. Aitcin PC, “Cements of yesterday and today Concretes of tomorrow”, Cement and Concrete Research, Vol. 30, (2000), pages 1349 to 1359.3. Khadiranaikar RB and Muranal SM (2012) “Factors affecting the strength of reactive powder concrete (RPC)” International Journal f Civil Engineering and technology volume 3 number 24. Chrisholm DH and Lee NP (2005) “Reactive powder concrete”