Engineering properties and durability of concrete samples designed by densified mixture design algorithm (DMDA) method incorporating steel reducing slag aggregate

Abstract

This research aimed to examine concrete specimens' mechanical and durability properties that included the steel reducing slag aggregate (SRSA) as a complete replacement for natural fine and coarse aggregate. The concrete samples were designed using the DMDA method with water content controlled around 160 kg/m3 and the water to binder (W/B) ratio at 0.3 and 0.4. The SRSA was used as a total replacement for natural fine aggregate, natural coarse aggregate, etc. The experimental tests including slump, slump flow, fresh unit weight, compressive strength, splitting tensile strength, water absorption and porosity, electrical surface resistivity (ESR), thermal conductivity (TC), drying shrinkage, sulfate attack resistance were used to conduct the engineering properties and durability of concrete samples, while microstructure analysis was observed by using scanning electron microscopy (SEM) micrographs. The experimental results illustrated that using SRSA improved the compressive strength of concrete samples in early and reduced in later age. The incorporating SRSA reduced the mechanical properties and durability of concrete specimens. However, all the concrete exhibited a good corrosion resistance with a high ESR value and stable mass change under sulfate attack solution. Besides, the utilization of fine SRSA showed a better performance than coarse SRSA.