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Fresh‐state performance design of green concrete mixes with reduced carbon dioxide emissions
Author(s) -
Şanal İrem
Publication year - 2018
Publication title -
greenhouse gases: science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.45
H-Index - 32
ISSN - 2152-3878
DOI - 10.1002/ghg.1826
Subject(s) - cementitious , materials science , compressive strength , fly ash , cement , aggregate (composite) , mortar , carbon dioxide , rheology , composite material , viscosity , environmentally friendly , waste management , chemistry , ecology , organic chemistry , engineering , biology
The use of environment‐friendly cement‐replacement materials results in concrete mixes with significantly reduced water‐to‐binder ratios, leading to increased viscosity and yield stress. This may be considered a hindrance to the widespread implementation of this green concrete technology. In this comprehensive experimental study, a performance‐based design was applied to select different concrete mixtures for reduced carbon dioxide (CO 2 ) emission and improved performance in terms of both fresh and hardened states. A parameter study was carried out to study the rheological properties, compressive strength, and CO 2 emissions of 26 mortar mixes with different binder systems and different water‐to‐binder ratios (W/B) with the aim of determining alternative low‐environment impact combinations. A strong effect of the paste composition (binder amount) on the plastic viscosity and resulting CO 2 emissions was observed. For fixed proportions of paste and fine aggregate the plastic viscosity shows a non‐linear decreasing trend to the W/B ratio and non‐linear increasing trend to the B/(W+B) ratio. Finally, a successful candidate paste composition satisfying the performance requirements was selected as a reduced CO 2 emission alternative. The candidate paste composition (Mix No. 6) with relatively large amounts (fly ash / cement = 3) of supplementary cementitious materials (fly ash) was selected for the development of environment‐friendly concrete mixtures. The maximum compressive strength increase with this mix was found to be around 25% and maximum CO 2 reduction obtained was about 68% when compared to that of the control mix. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.