Durability and electrical resistivity of recycled abrasive stone aggregate concrete with GGBFS and polymer fibers

Although the use of decorative stones can satisfactorily meet architectural requirements, neglecting the wastes generated during stone polishing processes, particularly considering their chemical nature, may lead to significant environmental consequences. The present study investigates the effects of ground granulated blast furnace slag (GGBFS) as a pozzolanic material and waved macropolymer fibers (MP) on the electrical resistivity and durability performance of recycled concrete containing recycled abrasive stone aggregate (RASA). For this purpose, 108 cubic specimens and 108 cylindrical specimens corresponding to 36 different mix designs were prepared. The individual and combined effects of RASA, GGBFS, and MP on surface and bulk electrical resistivity, as well as durability-related properties, including water absorption, porosity, and density, were evaluated. In the mix designs, RASA was used to replace natural coarse aggregate at four volumetric levels of 0, 25, 50, and 100%. GGBFS replaced cement at three weight percentages of 0, 10, and 20%, while MP was incorporated into the concrete at three volumetric contents of 0, 0.75, and 1.25%. The findings indicated that although the incorporation of RASA particularly at high replacement levels (100%) led to reduced workability, increased water absorption by up to 35%, increased porosity by up to 20%, and reductions of up to approximately 79% in both surface and bulk electrical resistivity, as well as a decrease of about 10% in density compared with the reference mix, these adverse effects could be effectively mitigated through the simultaneous use of GGBFS and MP. The most appropriate design among the percentages used was identified as containing 25% RASA, 20% GGBFS, and 0.75% MP. This combination resulted in a of about 20% reduction in both water absorption and porosity, while improving surface electrical resistivity 75% and bulk electrical resistivity 45% compared with the reference mix, thereby providing the highest level of durability among all mixtures incorporating RASA. These findings confirm that, through intelligent mix design, it is possible to produce sustainable recycled concretes that not only reduce the consumption of natural resources but also exhibit satisfactory durability performance.