Investigation of mechanical characteristics and sustainable practices in concrete incorporating recycled marble waste

Abstract

Due to the rapid expansion of infrastructure, urbanization, and industry, there is a constant need for concrete worldwide. However, the expansion of the concrete sector increases pressure on natural resources, endangering the balance of the ecosystem. Thus, it would be advantageous to meet current concrete needs without reducing production quality by incorporating recycled materials into concrete mixes. In this work, we investigate the mechanical characteristics of environmentally friendly concrete using recycled marble powder (WMP) partially replacing cement and marble coarse aggregates (MCA) as an alternative to natural coarse aggregates. The qualities of the concrete were evaluated using a combination of destructive and non-destructive testing techniques. In this study, three series of mixes were prepared. The first series (S1) is composed of 100% natural coarse aggregates. In the second series (S2), 50% of the natural coarse aggregates are substituted for marble coarse aggregates, while the third series (S3) is composed of 100% marble coarse aggregates. In each of the three series, Marble powder was used in place of cement at a percentage ranging from 5% to 20%, increasing by 2.5%. Concrete mixes were developed and evaluated with different levels of marble waste substitution to compare their compressive strengths and workability to those of traditional concrete made from 100% natural aggregates. Simultaneously, the strength characteristics were measured using the Schmidt hammer and ultrasonic velocity tests. As was mentioned, in the three series, when Cement is replaced with marble powder, the slump decreases, even though the incorporation of marble coarse aggregates tends to increase this workability, while the compressive strength shows an increase of 28.66% and 31.63% compared to the control mix for 50% and 100% substitute of natural coarse aggregates with marble coarse aggregates, respectively. It is also noteworthy that concrete containing marble waste exhibits normal ultrasonic velocity. For concrete mixtures of series (S1), (S2), and (S3), respectively, the velocity of ultrasonic pulses increased by 18.20%, 27.44%, and 27.98%, while the Schmidt Rebound Number increased by 10.13%, 14.52%, and 21.37%, respectively, in contrast to the values of the control mixture. Additionally, the reliability of results from the universal testing machine (UTM) was validated through correlation analysis of compressive strength measurements obtained by various methods. The study's findings are intriguing and underscore the potential of employing marble waste as an alternative to natural aggregates.