Assessment of the Carbon Storage Potential of Portuguese Precast Concrete Industry

The concrete sector is known for its significant contribution to CO₂ emissions. There are two main contributing factors in this situation: the large amount of concrete consumed per year on the planet and the high levels of CO₂ released from the manufacture of Portland cement, the key binding agent in concrete. To face the consequent sustainability issues, diverse strategies involving the carbon capture and storage potential of cementitious materials have been explored. This paper addresses the potential of storing CO₂ in concrete during the curing stage within the context of the precast Portuguese industry. To this end, it was assumed that CO₂ will become a waste that will require an outlet in the future, considering that carbon capture will become mandatory in many industries. This work concluded that, in terms of carbon retention, the net benefit is positive for the process of storing carbon in concrete during the curing stage. More specifically, it was demonstrated that the additional emissions from the introduction of this new operation are only 10% of the stored amount, returning a storage potential of 76,000 tonnes of CO₂ yearly. Moreover, the overall net reduction in the concrete life cycle averages 9.1% and 8.8% for precast elements and only non-structural elements, respectively. When a low-cement dosage strategy is coupled with carbonation curing technology, the overall carbon net reduction is estimated to be 45%.