Title: Potential of CO2 mitigation in concrete containing recycled aggregates

Authors: Bruno Luís Damineli; Javier Mazariegos Pablos

Addresses: Institute of Architecture and Urbanism, University of Sao Paulo, 13566-590, Sao Carlos, Brazil ' Institute of Architecture and Urbanism, University of Sao Paulo, 13566-590, Sao Carlos, Brazil

Abstract: The replacement of natural aggregates with recycled ones is a strategy for developing sustainable concrete formulations, which could decrease landfill disposal of construction waste. However, the increase of recycled aggregates (RA) content in concrete frequently leads to an increase in cement content - which is the heaviest environmental burden of concrete due to CO2 emissions. This study presents a strategy for a better engineered concrete design approach that could allow using RA without increasing cement content. From a more detailed aggregate characterisation, a known particle packing theory could be applied to optimise the concrete packing of particles, allowing a decrease in cement content. The eco-efficiency of cement use was assessed by Binder Index (BI) - the ratio between binder content (environmental load) and compressive strength (performance indicator). Better-engineered concrete could provide similar efficiency of cement use in packed concrete formulations with 100% low-quality RA compared to ordinary ones with 100% natural aggregates.

Keywords: concrete; aggregate; waste treatment; particle size distribution; mixture proportion.

DOI: 10.1504/IJESD.2021.114565

International Journal of Environment and Sustainable Development, 2021 Vol.20 No.2, pp.150 - 165

Received: 10 Sep 2019
Accepted: 03 Jul 2020

Published online: 27 Apr 2021 *

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