LOW CARBON CONCRETE COMPOSITION AND A METHOD TO PRODUCE A LOW CARBON CONCRETE COMPOSITION
A low carbon concrete composition and a method to produce a low carbon concrete composition, as well as to a premix comprising hydraulic binder and admixtures. A mineral ingredient includes biochar and a filler selected from limestone and/or siliceous material.
1 . A mineral ingredient for concrete/mortar composition comprising biochar and a filler selected from limestone and/or siliceous material.
2 . The mineral ingredient according to claim 1 , wherein the weight ratio between biochar and filler is ranging from 0.1 to 5.0.
3 . The mineral ingredient according to claim 1 , wherein biochar is obtained by the thermal decomposition of biomass at a temperature higher than 300° C.
4 . The mineral ingredient according to claim 1 , wherein biochar has a maximum size of 5 mm and a minimum size of 0 mm.
5 . The mineral ingredient according to claim 1 , wherein limestone filler is in the form of particles having a D90 less than or equal to 200 μm; siliceous material filler is in the form of particles having a D50 comprised between 30 to 60 μm.
6 . A cement composition comprising mineral ingredient according to claim 1 , and Portland cement.
7 . The cement composition according to claim 6 , comprising between 15 wt.-% and 50 wt.-% of the mineral ingredient compared to the total weight of the composition.
8 . The cement composition according to claim 6 , comprising between 50 wt.-% and 85 wt.-% of the amount of Portland cement, compared to the total weight of the composition.
9 . The cement composition according to claim 6 , wherein Portland cement comprises a Portland clinker and an optional additional mineral component.
10 . The cement composition according to claim 9 , wherein the additional mineral component does not constitute more than 20% by weight of the total weight of the Portland cement.
11 . A hydraulic composition for mortar and/or concrete comprising
a cement composition according to claim 6 ,
sand and/or aggregates, and
water.
12 . The hydraulic composition according to claim 11 , comprising
at least 10% of the cement composition; and
up to 90% of sand or aggregates,
the percentages corresponding to volume proportions relative to the total volume of the hydraulic composition.
13 . The hydraulic composition according to claim 11 , wherein the water to cement composition ratio is at least 0.3, preferentially comprised between 0.4 and 0.9.
14 . The hydraulic composition according to claim 11 , further comprising at least one admixture selected from an accelerator, a viscosifying agent, a retarder, a clay inerting agent, a shrinkage reducing agent, a defoaming agent, a plasticizer and/or a superplasticizer.
15 . The hydraulic composition according to claim 11 , further comprising fibers.
16 . A process for preparing a cement composition according to claim 6 , comprising mixing the Portland cement and the mineral ingredient.
17 . The process according to claim 16 , wherein all the limestone and/or siliceous material comprised in the cement composition is brought only by the filler of the mineral ingredient.
18 . The process according to claim 16 , wherein one part of limestone and/or siliceous material comprised in the cement composition is brought only by the filler of the mineral ingredient and the other part of limestone and/or siliceous material is added to the cement composition.
19 . A method comprising utilizing a mineral ingredient as defined in any one of the preceding claims in a cement composition as defined in claim 6 .
20 . A process for preparing a hydraulic composition according to claim 11 , comprising mixing the Portland cement and the mineral ingredient.