Sustainable use of boron waste and volcanic scoria in slag-based self-compacting alkali-activated mortars: fresh, mechanical and durability properties

Sustainable self-compacting alkali-activated concrete (SCAAC) manufacturing is an environmentally friendly concrete that has a reduced carbon footprint than ordinary concrete. Alkali-activated binders have been demonstrated in experiments to reduce concrete's energy consumption and carbon emissions by over 50%. This paper focuses on manufacturing boron waste (BW), volcanic scoria (VS) and ground blast furnace slag (GBFS) incorporated binary and ternary blends of self-compacting alkali-activated mortars (SCAAM). The main objective of this study is to investigate the fresh, mechanical, durability and microstructural properties of SCAAM based on binary and ternary mixtures of BW, VS, and GBFS. SCAAM samples were synthesized at 60 °C and 100 °C for 72 h then exposed to ambient cured at 3, 28 and 90 days. The compressive strength, flexural strength, physical, and sorptivity properties of the SCAAM mixtures, as well as flowability, were investigated. The performance of the produced blends at freeze-thaw exposure were also examined. SEM, and EDS was also used to examine the microstructures of the mixtures. The findings showed that 50% GBFS and 50%VS based SCAAM mixture heat cured at 100oC activated with NS/NH ratio of 3.0 produced a compressive strength of 40 MPa at 90 days. The findings indicated that inclusion of BW to the SCAAM mixtures decreased the compressive strength notably regardless of NS/NH ratio and curing temperature. Inclusion of BW also affected the durability performance negatively.