MECHANICAL PROPERTIES OF EPOXY AND CONCRETE BASED COMPOSITE MATERIALS REINFORCED WITH OIL SHALE ASH.

The elastic properties of composites with reinforcing particles are under investigation in this research. Oil shale ash (OSA), produced in Estonia, is a powder and a by-product of the combustion process in generation of electricity at power plants. During previous years many thousands of tons of OSA have been collected. Starting from 2018 in the European Union, oil shale ash is no longer considered as toxic and hazardous waste, this is opening new possibilities for commercial application of OSA in new products and giving it a second life. Recycling and reusing oil shale ash is therefore an important problem for environmental sustainability. The use of this product as a reinforcement for epoxy resin matrix as well as for the concrete matrix in Epoxy/OSA and Concrete/OSA composites was experimentally investigated in this work. Several sets of Epoxy/OSA specimens were experimentally fabricated: Epoxy resin without OSA, Epoxy resin with 10% of oil shale ash by weight and sets of specimens with increasing ratios (10% increase between) of oil shale ash by weight, until a 50% ratio of OSA was reached. The tensile test experiments were conducted with the goal to obtain elastic modulus of the oil shale ash composite material. Tensile tests were realized according to ISO 527-1:2012 and specimens were fabricated according to ISO 527-2:2012 1B standards. Tensile tests were performed, and the experimental results were compared with predictions from analytical approaches. According to the obtained tensile test results and analytical predictions (using the rule of mixture and other approaches), the modulus of elasticity increases in direct proportion with increasing weight fraction of the oil shale ash in the composite material. Finally, samples of concrete with OSA were fabricated and tested until failure. Different amounts (by weight) of cement (0%, 5%, 10%, 15%, and 35%) in the samples were replaced by OSA. The elastic properties of these samples were also experimentally evaluated and compared with theoretical prediction results. [ABSTRACT FROM AUTHOR]