An Investigation into the Performance of Reactive Powder Concrete (RPC) containing Recycled Metal Spring and its Comparison with the Concrete including Steel Fibers Exposed to the Acidic Environment

Reactive Powder Concrete (RPC) is a developing composite cementitious material that will allow the concrete industry to optimize material use, generate economic benefits and build structures that are robust, durable and environmentally friendly. This paper deals with the performance of reactive powder concrete (RPC) containing recycled metal spring and its comparison with that of including steel fibers exposed to the acidic environments. To this end, a number of specimens were built in 10×20 cm metal cylindrical formworks in ambient temperature (around 25°c) containing 0.3 and 0.6% of steel fibers and recycled metal spring in concrete volume, respectively so as to conduct the tensile and compressive strength tests in compliance with ASTM C39. Subsequently, the specimens were cured in an environment with magnesium sulfate content of 0, 5 and 10% within 28 days. Based on the results, addition of recycled metal spring and steel fibers to the RPC, managed to improve the compressive and tensile strengths by 50 to 60%. Moreover, the specimens containing recycled spring better withstood against the acidic environments in comparison with the specimens including steel fibres. In general, it was found that due to the negligible difference between the strength of the specimens, application of metal recycled spring in reactive powder concrete is technically and economically justifiable.