The negative environmental impacts associated with the usage of Portland cement (PC) in concrete induced intensive research into finding sustainable alternative concrete mixes to obtain “green concrete”. Since the principal aim of developing such mixes is to reduce the environmental impact, it is imperative to conduct a comprehensive life cycle assessment (LCA). This paper examines three different types of sustainable concrete mixes, viz., alkali-activated concrete (AAC) with natural coarse aggregates, AAC with recycled coarse aggregates (RCA), and bacterial concrete (BC). A detailed environmental impact assessment of AAC with natural coarse aggregates, AAC with RCA, and BC is performed through a cradle-to-gate LCA using openLCA v.1.10.3 and compared versus PC concrete (PCC) of equivalent strength. The results show that transportation and sodium silicate in AAC mixes and PC in BC mixes contribute the most to the environmental impact. The global warming potential (GWP) of PCC is 1.4–2 times higher than other mixes. Bacterial concrete without nutrients had the lowest environmental impact of all the evaluated mixes on all damage categories, both at the midpoint (except GWP) and endpoint assessment levels. AAC and BC mixes are more expensive than PCC by 98.8–159.1% and 21.8–54.3%, respectively.

Geotextiles are widely used for reinforcing soil, improving drainage, controlling soil erosion and embankment construction. Existing research recommends the improvement of soil in an economic and eco-friendly manner using jute geotextiles. However, jute fibres have the tendency to degrade in the acidic and alkaline environment of the soil. Jute geotextile treated with antimicrobial chemicals are used as a substitute for manmade geosynthetics, as it improves the life expectancy of jute. But these chemicals are expensive and are a potential source of leaching. The present study aims to develop a fly ash-based treatment procedure that is economic, ecologically safe as well as significantly improves the engineering and strength properties of jute as a geotextile. There is an increasing interest in the application of alkali-activated binders (AAB) in engineering practices. It is produced by the reaction between an aluminosilicate precursor (primarily Class F fly ash and/or slag) and alkali activator solution. AAB-treated jute geotextile shows that the load-bearing capacity increases by 27% approximately. The vertical permeability of sand does not vary significantly with the inclusion of AAB-treated jute. The tensile strength of jute also exhibits a marked improvement following the treatment. Thus, the technique proposed in this study has the potential for implementation in practical applications.

The scientific community is shifting its focus towards construction materials with a low carbon footprint, such as alkali-activated concrete (AAC). The present study conducts an environmental impact assessment using the cradle-to-grave approach to examine the environmental implications of three different types of ambient-cured AACs with varied combinations of precursors. The 28-day compressive strength values of the concrete mixes used for comparing environmental impacts vary from 35 to 55 MPa. Among these mixtures, the one with the least environmental impact is chosen for further impact assessment with the inclusion of fibers. Three different fiber reinforced AAC mixes containing 0.3% steel, glass, and polypropylene fibers, respectively by volume of AAC, are used in this study. The findings show that Portland Cement concrete has 86% and 34% higher impacts than AAC on the ecosystem and human health, respectively. In the production of AAC, sodium silicate is found to have the highest impact on the environment, in the range of 30–50% of the total impact. Among the various fibers used, glass fibers have the highest impact, which is 12% and 13% higher than that of the plain AAC mix, on the ecosystem and human health, respectively.