Investigation of mechanical properties of a new type of acid resistant concrete

Exposure of the concrete structures to the acidic environment is sometimes unavoidable and there is a need to find some concrete mixes with more resistance to such harsh environments. None of the concrete mixes offered so far has met all the requirements in terms of strength, economy, and sustainability together. In this paper a new concrete composition, called Renderoc-G was tested in the Concrete Laboratory at the University of Technology Sydney to identify its behaviour subjected to acidic environments. To assess the mechanical properties of this new concrete, standard tests were carried out to compare main mechanical characteristics of the specimens made by this new material with the plain concrete. The mechanical tests include compressive strength, MOE (Modulus of Elasticity) and MOR (Modulus of Rupture). All tests have been conducted for both Renderoc-G and plain concrete and also with and without the presence of acidic environments. The specimens were cured for 28 days in lime saturated water. Afterwards, they were immersed in sulfuric acid solution with 7% concentration by volume (12.8% by weight) and were tested during a period of 8 weeks. To evaluate the effect of acid on mechanical properties of the specimens immersed in acid solutions, the same number of specimens in standard curing conditions was also tested on the same day. The investigation of mechanical properties of Renderoc-G showed that it can maintain its mechanical properties to an acceptable level even after several weeks of immersion in acid solution whereas, ordinary concrete loses so much mass in addition to its most important mechanical property, namely, compressive strength, remarkably. This finding may provide opportunities for structural applications of this new material in the future.