Ideal dosage curves for limestone and EAFS aggregate concretes and their sustainability assessment

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.