KIBECO RECO. Concrete without unnecessary cement. 

KIBECO RECO is an innovative concrete solution that, thanks to Annex ND of SN EN 206:2013+A2:2021, can save cement without compromising on performance. This concrete contains recycled Swiss aggregate and permanently stores carbon dioxide, which is bound by the Neustark process. KIBECO RECO meets all standard-relevant quality criteria and can be recycled without releasing CO₂. These types of concrete are currently the lowest-emission solution on the market.

In contrast to conventional concrete, KIBECO RECO contains up to 130 kg/m³ less cement, around 10 kg/m3 of stored CO₂ and recycled aggregate. You can achieve a 35% lower carbon footprint with KIBECO RECO than with conventional concrete.

Thanks to cement savings of up to 130 kg/m³ and CO₂ storage of 10 kg/m³ through CO₂ sequestration, KIBECO RECO has a carbon footprint 35% lower than conventional concrete. In addition, ≥26% recycled aggregate is used.

Concrete granulate extracted from the dismantling of buildings is treated with carbon dioxide separated from the atmosphere. Mineralisation permanently binds the CO₂ in crystalline form. The concrete granulate thus treated is added to the fresh concrete as a gravel substitute.

The Neustark process enables permanent storage of 10 kg of climate-damaging CO₂ per cubic metre of fresh concrete. 

A comparison: a beech has to grow for around 80 years to absorb one tonne of CO₂ (source: co2online/carbon-connect). In addition, the trees may be burned at the end of their lives releasing the CO₂ they had absorbed over the years. In contrast, the mineralisation of CO₂ in concrete granulate through the Neustark process guarantees permanent CO₂ storage.

Generally speaking, the CO₂ used industrially in Switzerland comes from abroad. We do it differently. We obtain 100% of the CO₂ we use from the atmosphere in Switzerland. The CO₂ is extracted from the atmosphere through a biogenic process at the Bern wastewater treatment plant in Herrenschwanden. The CO₂ is then delivered to our production facility in a climate-neutral manner by biogas-powered truck.

When a concrete wall is exposed to air, the carbon dioxide [CO₂] reacts with the calcium compounds in the cement phases [Ca(OH)2] and forms calcite crystals [calcium carbonate, CaCO3]. CO₂ is thus permanently bound in the crystals (mineralised). This naturally occurring reaction, also known as “natural mineralisation” or “carbonation,” is well known in the construction industry and is accelerated and multiplied in the process developed by Neustark.

The CO₂ uptake of 10 kg per tonne of concrete granulate is measured and documented in the Neustark process using both a CO₂ flow measurement and a balance, whereby the two independent measurement methods reliably lead to the same measurement result. 

No. The reinforcement rusts in the concrete because the concrete becomes more acidic during the natural mineralisation process and the pH value is reduced as a result. Carbonation by the Neustark process takes place before the granulate is mixed with cement and water. The pH value thus remains the same as for non-mineralised concrete.

A natural process:

the main constituent of cement is calcium oxide [CaO]. It is extracted from limestone, which mainly consists of calcite crystals [calcium carbonate, CaCO3]. The limestone is fired in the cement plant at around 1,400°C, which releases CO2: the calcium oxide [CaO] is left behind and is further processed into cement products. The cement is finally mixed with water, gravel and sand to form concrete.

CaCO3 --> CaO + CO2

When a concrete wall is exposed to air, the carbon dioxide gas [CO2] from the air reacts naturally with the calcium compounds in the cement phase [CaO]. In the fine pores and cracks, calcite crystals [calcium carbonate, CaCO3] form, which can permanently bind CO2. The natural reversal of the above-mentioned reaction thus occurs.

CaO + CO2 --> CaCO3

However, this is a slow process. During the life of a building, only a few millimetres of the concrete surfaces are carbonated.

Permanent CO2 capture:

CO2 is permanently captured by the formation of crystals (mineralisation). This naturally occurring reaction is known in the construction industry as carbonation and is accelerated and multiplied in concrete granulate through the Neustark process.

KIBECO building materials are thus permanent and sustainable CO2 storage vehicles and can also be recycled or further treated in the next generation without risking CO2 release.

No increased risk of corrosion of the reinforcement:

Carbonation with the Neustark process takes place before the concrete granulate is mixed with cement and water. The pH value thus remains the same as for non-mineralised concrete. This means the risk of corrosion remains the same as with conventional concrete.

Thanks to the optimised material properties of KIBECO RECO, we do not include any excess compressive strength. As a result, the reinforcement can be reduced, bringing down material costs.

CO₂ storage fills voids in the recycled granulate, making the material denser. This not only improves the material properties, but also leads to a higher modulus of elasticity comparable to that of primary concrete.

Thanks to the targeted alignment of the aggregate and the use of recyclable fillers, our RECO concretes achieve a particularly high packing density. This reduces the need for cement and water, improves processability and increases durability – a key lever for CO₂-optimised construction in accordance with Annex ND.

A reduced cement content has advantages. The lower the final strength, the smaller the crack widths, which makes a reduced structural minimum reinforcement possible and thus saves both emissions and costs.

Up to 130 kg/m³ of cement can be saved by using the optimised concrete as per Annex ND of SN EN 206:2013+A2:2021. As a result, CO₂ emissions can be reduced by 35% without changing the material properties.

KIBECO RECO is suitable for all applications where conventional concrete is also used. 

Like conventional concrete, KIBECO RECO is produced in the concrete plant and delivered to the construction site by mixer truck. It is placed in the formwork and post-treated as usual. No additional training is required for construction company staff.

Where possible, delivery is made with electric mixer trucks to reduce transport emissions. Using an electric mixer truck saves more than 12 kg of CO₂ eq. per 100 tonne-kilometres. That’s more than 60% of greenhouse gas emission.

-          KIBECO RECO200: NPK B, C25/30, Dmax_32 or 16

-          KIBECO RECO300: NPK C, C30/37, Dmax_32 or 16

KIBECO RECO is already available in all regions via KIBAG. Please contact us directly for further information and orders.

The price difference varies depending on the project and requirements. You can find a detailed overview in our current price list under KIBECO. For more detailed information, please contact us directly.