Sustainable urban heat island mitigation with carbonated aggregate-based cement composites

Abstract

The rapid increase in atmospheric CO₂ levels, predominantly resulting from anthropogenic activities, constitutes a significant challenge due to its critical role in driving climate change. Major CO₂ emitters include the steel and cement industries, with Portland cement production alone responsible for approximately 0.98 tonnes of CO₂ per tonne of clinker produced. This study addresses CO₂ emissions from these industries through a multifaceted approach that combines direct emissions reduction, advanced CO₂ capture technologies, and Urban Heat Island (UHI) mitigation strategies. This methodology employs by-products from the food and steel industries as agents for carbon capture and storage (CCS) through mineral carbonation. These carbonated by-products are subsequently transformed into cementitious materials exhibiting high solar reflectivity, specifically designed for urban infrastructure applications. These materials are intended to mitigate the UHI effect, thereby resulting in lower urban temperatures and reduced energy consumption for air conditioning. Enhanced urban livability and public health benefits have been observed, characterized by a reduced incidence of heat-related illnesses. In conclusion, the holistic strategy of utilizing industrial waste for CO₂ sequestration and developing cool cements presents a promising pathway to combat climate change. This approach not only addresses CO₂ emissions but also promotes sustainable urban environments and supports a circular economy.