ABSTRACT

Experimental tests, and two conventional grading curves, are used to design a dosing scheme, seeking the best way to enhance the general sustainability of certain types of low-to-medium workability concrete mixes. The aim is to achieve highly compacted aggregate gradations, thereby minimizing the need for Portland cement consumption. Several aggregate mix designs, employing fractions of both commercial limestone and recycled electric steelmaking slag, were prepared and assessed. Nine concrete mixes of structural quality (above 40 MPa as compressive strength) were manufactured to analyze their aggregate packing density and their performance as engineering concrete mixtures. The results obtained after classical testing showed excellent quality homogeneous concrete mixes, considering both the in-fresh and in-hard properties. Subsequently, a sustainability analysis of all the mixes led to the conclusion that they were of low environmental impact, due to their high aggregate content and their low cement consumption which, additionally, included other industrial co-products with hydraulic properties.

ACKNOWLEDGEMENTS

The authors wish to express their gratitude to the Basque Government Department of Education for its pre-doctoral funding (PRE_2018_2_0289) and to PID2021-124203OB-I00 and RTI2018-097079-B-C31 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, by the “European Union”. Our thanks also to the SAREN Research Group (IT1619-22, Basque Government), the Baskrete initiative and the Transnational Common Laboratory “Aquitaine-Euskadi Network in Green Concrete and Cement-based Materials” for their financial support. We are likewise grateful to Morteros y Revocos Bikain, HORMOR, FYM Heidelberg Cement Group, and the Amantegui Group for supplying the materials used in this research.