Methodology - CO2 calculator
Where does the CO2 calculator's data come from?
The CO2 calculator uses two main types of data; CO2 data and early strength data. The CO2 data comes from the branch EPDs created by the Dansk Beton Fabriksbetonforeningen. The early strength data comes from the average Maturity Curve of each strength class. In this article, we are going to explain both types of data and how they were obtained.
Find the CO2 calculator here.
Table of Contents
CO2 calculator data
What are EPD's?
Environmental Product Descriptions (EPD) are independently verified and registered documents that analyze the environmental impact of products during all or some of their life-cycle.
For concrete mixes, the EPD life-cycle is divided in:
EPD Flowchart
EPDs are interesting because they allow customers or the general public to compare the environmental impact of different concrete mixes. Some of the included impacts are the equivalent CO2, acidification of fjords and water or eutrophication among others. For the calculator, we decided to only include CO2 as this is the most used parameter in the construction industry. Furthermore, the CO2 emissions displayed in the calculator are only from the Concrete Production (A1-A3) phase. This decision was taken due to the increased variability in the CO2 results during the later phases.
Early strength data
The strength data presented in the calculator comes from the concretes’ Maturity Curve. This curve represents the relationship between concrete maturity and strength and is the basis of the Maturity Method. Below, you can see an example of a maturity curve:
Each concrete mix has a specific strength development and therefore, its Maturity Curve will also be unique. For the calculator, we have taken the average of the Maturity Curves for each strength class from the Maturix Concrete Library.
Another factor we included in the calculation is the ambient temperature. Temperature influences how fast the concrete gains its strength. In the ASTM1074, 20°C (23°C in the US) is used as the reference temperature. However, if you have a project where the temperature is above or below this, the speed of the strength development will accelerate or slow down respectively.
