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T he durability of concrete subjected to an aggressive environment is a major issue faced by constructional engineers. Many researchers have tried to evaluate the durability characteristics of concrete against aggressive fluids. Amongst the fluids, compounds of sulphuric acid and chloride ions caused massive deterioration in concrete. Reactive powder concrete (RPC) is a type of ultra-highstrength cement composite. In the present study, an effort is made to assess durability properties of RPC. T he RPC with compressive strengths 110, 120 and 130MPa have been produced. Acid immersion test, salt crystallization test and chloride ion penetration tests have been carried out to assess the degradation of concrete. Samples were exposed to sulphuric acid solutions over a period of 60 days with concentrations varying from 0.5-2%. The salt crystallization tests were carried out by immersing samples in 14% Na2SO 4 solutions. Visual observations and deterioration in terms of mass and compressive strength reductions are recorded. The RPC showed high resistance towards the crystallization of salts. A significant amount of weight loss and strength loss was observed for the samples exposed to high concentrations of sulphuric acid. A negligible amount of chloride ion penetration was observed.

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Reactive powder concrete (RPC) is a type of ultra-high strength cement composite material. It has advanced mechanical properties and shows high ductility characteristics. Many researches have shown that normal and high strength concrete fails under cyclic stresses at load level below its static capacity.In the present study, the mix design guidelines to produce high strength RPC is provided. RPC with compressive strength of 120, 130 and 140MPa was produced. The mechanical properties are obtained for hardened concrete. The present study focuses on the investigation of reactive powder concrete under uniaxial compressive cyclic loading. The investigation was carried out on cubical and cylindrical specimens. The behaviour of RPC under cylic loads is studied by obtaining the stress-strain characteristics under monotonic loading and cyclic loading. Three main types of tests were performed. Stress-strain envelope curve, common point curve and stability point curves were established under repeated load cycles. The limiting stress values required for design are provided. It was concluded that peak stress of the stability point curve could be regarded as the maximum permissible stress. A nonlinear analytical expression was proposed for the normalized stresses and strain which shows a precise fit with the experimental data. The expression will assist in predicting the cyclic response of concrete required for constructional applications.