Limitations of life cycle assessment of green concretes - a state-of-the-art review

Abstract

There have been numerous researches focusing on the alternatives to conventional concrete regarding environmental benefits and trade-offs. For this purpose, nowadays, the Life Cycle Assessment (LCA) is widely used. Until now, LCA results of conventional and green concretes have shown some limitations, and this paper focuses on addressing them. Firstly, the researches have been mostly based on a small number of concretes, which can limit the possibility to quantify the range of emissions for different set of assumptions. The second one is regarding the appropriate selection of functional unit where a divergence between different researches is visible. Moreover, it has been recognised that the criteria involved in the investigation of transportation might lead to the variation of results. Also, inventory allocation has to be assessed in detail to reach adequate distribution of the environmental impact of the concrete during its life cycle phases. Finally, CO₂ uptake of the concretes throughout the life cycle should be considered and applied adequately to have representative results of overall CO₂ emissions. It is expected that the differences will depend on construction practices among the countries where the researches are executed. Also, the results will surely vary between different system definitions when LCA is applied.