Low-carbon classification of concrete in Finland
A low carbon classification system for concrete has been developed in Finland. BY Low Carbon Classification has been created in cooperation with Finnish Concrete Association, Confederation of Finnish Construction Industries RT and Aalto University.
The target was to create a transparent, open system to classify concretes based on CO2-emissions. BY Low Carbon Classification does not limit competition between concrete suppliers in any way; a contractor selects a low carbon class for the whole project or for a structure. The concrete producers inform which BY Low Carbon Classes they have available for different types of concrete.
BY Low Carbon Classification contains 18 different types of ready-mixed concrete, 17 different types of precast element concrete and 5 different low carbon classes. Different strength classes qualify as different types of concrete and frost-resistant as well as salt-freeze resistant concretes as additional types. The reference level (GWP.REF) corresponds to the average CO2 emission level of each type of concrete. The values of the reference level are determined with the help of inquiries made among the Finnish concrete industries in the summer of 2021. The other classes (GWP.85, GWP.70, GWP.55 and GWP.40) are calculated from the reference level in 15% descending steps. The lowest class (GWP.40) corresponds to an emission level of 40% compared with the reference level. New classes can be added in the system in the future as needed.
The limit values of each BY Low Carbon Class are GWPtotal values presented as kg CO2e/m3 of concrete. The methods of Environmental Product Declarations are followed and phases A1…A3 are included. A web-based calculation tool has been created to calculate the GWPtotal values for different types of concrete. The calculation is based on the mix design of the concrete. The transportation of the raw materials is taken into account using the actual transportation distances. Also, the energy consumption and the amount of waste from concrete production are taken into account. Pre-determined specific CO2 emission values are used for each raw material, mode of transport and energy source. The specific emission values of cements will be updated annually because cement plays a major role in the CO2 emissions of concrete.
It is believed that BY Low Carbon Classification will boost the development of low-carbon concretes in Finland. BY Low Carbon Classification gives the concrete producer full freedom to choose the methods to reduce CO2 emissions.
Table 1. Types of ready mix concrete covered by BY Low Carbon Classification® and limit values of BY Low Carbon Classes. The values are GWPtotal values and include modules A1…A3. The values are given in kg CO2e/m3.
Type of concrete | GWP.REF | GWP.85 | GWP.70 | GWP.55 | GWP.40 |
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C20/25 | 210 | 180 | 145 | 115 | 85 |
C25/30 | 230 | 195 | 160 | 125 | 90 |
C30/37 | 255 | 215 | 180 | 140 | 100 |
C35/45 | 285 | 240 | 200 | 155 | 115 |
C45/55 | 320 | 270 | 225 | 175 | 130 |
C50/60 | 340 | 290 | 240 | 185 | 135 |
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C30/37 – Air-entrained | 290 | 245 | 205 | 160 | 115 |
C35/45 – Air-entrained | 330 | 280 | 230 | 180 | 130 |
C45/55 – Air-entrained | 375 | 320 | 265 | 205 | 150 |
C50/60 – Air-entrained | 395 | 335 | 275 | 215 | 160 |
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C30/37 P0 | 270 | 230 | 190 | 150 | 110 |
C30/37 P30 | 300 | 255 | 210 | 165 | 120 |
C35/45 P0 | 300 | 255 | 210 | 165 | 120 |
C35/45 P30 | 330 | 280 | 230 | 180 | 130 |
C35/45 P50 | 340 | 290 | 240 | 185 | 135 |
C45/55 P50 | 375 | 320 | 265 | 205 | 150 |
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P0, P30 and P50 are salt-frost resistant concretes used in the concrete infrastructure |
Table 2. Types of concrete used in precast concrete elements covered by BY Low Carbon Classification® and limit values of BY Low Carbon Classes. The values are GWPtotal values and include modules A1…A3. The values are given in kg CO2e/m3.
Product group | Concrete | GWP.REF™ | GWP.85™ | GWP.70™ | GWP.55™ | GWP.40™ |
---|---|---|---|---|---|---|
Hollow-cores and floor plates | C40/50 | 270 | 230 | 190 | 150 | 110 |
C50/60 | 295 | 250 | 205 | 160 | 120 | |
C60/75 | 340 | 290 | 240 | 185 | 135 | |
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Frame products1 | C35/45 | 315 | 270 | 220 | 175 | 125 |
C40/50 | 335 | 285 | 235 | 185 | 135 | |
C45/55 | 350 | 300 | 245 | 195 | 140 | |
C50/60 | 360 | 305 | 250 | 200 | 145 | |
C55/67 | 375 | 320 | 265 | 205 | 150 | |
C60/75 | 390 | 330 | 275 | 215 | 155 | |
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Other precast elements2 | C30/37 | 290 | 245 | 205 | 160 | 115 |
C30/37 air-entrained | 310 | 265 | 215 | 170 | 125 | |
C35/45 | 320 | 270 | 225 | 175 | 130 | |
C35/45 air-entrained | 340 | 290 | 240 | 185 | 135 | |
C40/50 | 350 | 300 | 245 | 195 | 140 | |
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Walls, white cement | C30/37 | 505 | 430 | – | – | – |
C35/45 | 525 | 445 | – | – | – | |
C40/50 | 555 | 470 | – | – | – | |
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1 Frame products: precast columns, precast beams, precast TT and HTT slabs
2 Other precast elements: wall panels, solid slabs, technical shafts, foundation elements, and lift shaft elements
Material in English:
BY Low Carbon Classification, Guideline Part 1: Background report
Article of Low Carbon Classification system in Betoni-lehti March 15th 2022 (in English).