Sustainability assessments of ternary mixed concrete: A cradle-to-gate analysis

The emissions of carbon dioxide into the atmosphere due to the rapid growth of construction activities and industrialization have raised global concerns on climate change. The indiscriminate disposal of agro-industrial wastes poses ecological challenges. Hence, this study aims to evaluate the sustainability of waste materials as constituents of concrete and to produce suitable cement substitutes to reduce energy consumption and carbon dioxide emissions. To achieve this goal, cement was partially replaced with waste wood ash (WWA, 5–15 wt%) and calcite powder (CP, 5–15 wt%) using a concrete mix ratio of 25 MPa. The samples were tested for slump and compressive strength. The embodied energy, global warming impact, and sustainability index of the concrete mixes were assessed using a cradle-to-gate analysis. The results showed an increase in compressive strength with increasing WWA and CP content in the ternary blends. The replacement of WWA (10 wt%) and CP (10 wt%) with cement showed the maximum compressive strength. The embodied energy and global warming potential of producing the ternary-mixed concrete decreased with increasing WWA and CP contents in the ternary mixes compared to the control concrete, resulting in high sustainability. The study's findings demonstrated that WWA and CP are environmentally friendly materials that can be used to produce sustainable concrete.