Abstract:
The construction industry heavily relies on materials, mainly concrete, posing
environmental challenges. To address this, 'greener' concrete options have
emerged, aiming to reduce reliance on new materials. Concrete grades are pivotal,
determined by mix designs based on compressive strength. Cement, fine and
coarse aggregates, water, and sometimes admixtures constitute concrete.
Incorporating non-conventional materials, like quarry dust, seeks to create more
eco-friendly concrete but lacks comprehensive life cycle inventory (LCI) data for
ready-mix concrete. This study conducts a 'cradle-to-use' life cycle assessment
(LCA) of two concrete types: one with conventional river sand and another
blending river sand with quarry dust, both meeting the 30 MPa strength standard.
Data from a quarry and batching plant are collected for environmental impact
assessment, considering material, water, electricity consumption, and waste
generated over two months. SimaPro Faculty version models the environmental
impact per m3 for both concrete types using ReCiPe 2016 v1.1 mid-point and
end-point characterization models. End-point analysis reveals lower human
health impact for the non-conventional concrete (0.0538 Pt) compared to
conventional (0.0762 Pt). Among 18 mid-point categories, "human carcinogenic
impact" ranks the highest for both concrete types, with the non-conventional
showing reduced impact (0.938 Pt) compared to conventional (1.27 Pt). Notably,
clinker production remains the primary source of environmental impact for both,
followed by electricity consumption during cement production. Replacement of
fine aggregate shows a modest reduction in environmental impact.
The study underscores the significantly lower environmental impact of non
conventional fine aggregates, particularly quarry dust. This establishes the non
conventional mix as a more environmentally friendly choice among the two
concrete scenarios.
