The method for producing a carbonate bonded, compacted article, which method comprises the steps of providing a particulate, carbonatable material; compacting the particulate material to form a compact; and carbonating said compact. The carbonation of the compact is started and subsequently continued for at least 1 hour with a low partial carbon dioxide pressure in the carbonation gas which is lower than 0.5 bars, after which carbonation of the compact is continued for at least 8 hours with a high partial carbon dioxide pressure in the carbonation gas which is higher than 0.5 bars. By carbonating in two phases with a low and a high partial carbon dioxide pressure, a higher compressive strength of the carbonated compacts can be achieved within a predetermined carbonation time, in particular within a carbonation time of about 24 hours so that every day new compacts can be carbonated.

The method for producing a carbonate bonded, compacted article, which method comprises the steps of providing a particulate, carbonatable material; compacting the particulate material to form a compact; and carbonating said compact. The carbonation of the compact is started and subsequently continued for at least 1 hour with a low partial carbon dioxide pressure in the carbonation gas which is lower than 0.5 bars, after which carbonation of the compact is continued for at least 8 hours with a high partial carbon dioxide pressure in the carbonation gas which is higher than 0.5 bars. By carbonating in two phases with a low and a high partial carbon dioxide pressure, a higher compressive strength of the carbonated compacts can be achieved within a predetermined carbonation time, in particular within a carbonation time of about 24 hours so that every day new compacts can be carbonated.

What is shown and described is a concrete element including a core concrete layer and a face concrete layer, the face concrete layer being obtained by compacting and hardening a mixture containing a latent hydraulic binder and/or a pozzolanic binder, water, a granular material and an alkaline hardener, with the granular material having, at a screen hole width of 2 mm, a through fraction from 35.5 wt. % to 99.5 wt. % and, at a screen hole width of 0.25 mm, a through fraction from 2.5 wt. % to 33.5 wt. %, each based on the total weight of the granular material.

What is shown and described is a concrete element including a core concrete layer and a face concrete layer, the face concrete layer being obtained by compacting and hardening a mixture containing a latent hydraulic binder and/or a pozzolanic binder, water, a granular material and an alkaline hardener, with the granular material having, at a screen hole width of 2 mm, a through fraction from 35.5 wt. % to 99.5 wt. % and, at a screen hole width of 0.25 mm, a through fraction from 2.5 wt. % to 33.5 wt. %, each based on the total weight of the granular material.

The carbonate bonded, press-moulded article is produced by press-moulding a particulate, carbonatable material that contains water and by carbonating the obtained compact with carbon dioxide gas. In order to be able to ensure an optimal compressive strength of the article two types of tests are provided. In the first type of test a sample of the particulate material is compressed with an increasing compaction pressure and when water starts to be expelled from the material as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is at least 7 MPa smaller than this compaction pressure. In the second type of test different samples of the particulate material are press-moulded with different compaction pressures and, after having released the compaction pressure, the density of the compact is determined. In case this density decreases instead of increases as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is smaller than this particular compaction pressure.

The carbonate bonded, press-moulded article is produced by press-moulding a particulate, carbonatable material that contains water and by carbonating the obtained compact with carbon dioxide gas. In order to be able to ensure an optimal compressive strength of the article two types of tests are provided. In the first type of test a sample of the particulate material is compressed with an increasing compaction pressure and when water starts to be expelled from the material as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is at least 7 MPa smaller than this compaction pressure. In the second type of test different samples of the particulate material are press-moulded with different compaction pressures and, after having released the compaction pressure, the density of the compact is determined. In case this density decreases instead of increases as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is smaller than this particular compaction pressure.

The carbonate bonded, press-moulded article is produced by press-moulding a particulate, carbonatable material that contains water and by carbonating the obtained compact with carbon dioxide gas. In order to be able to ensure an optimal compressive strength of the article two types of tests are provided. In the first type of test a sample of the particulate material is compressed with an increasing compaction pressure and when water starts to be expelled from the material as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is at least 7 MPa smaller than this compaction pressure. In the second type of test different samples of the particulate material are press-moulded with different compaction pressures and, after having released the compaction pressure, the density of the compact is determined. In case this density decreases instead of increases as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is smaller than this particular compaction pressure.

The carbonate bonded, press-moulded article is produced by press-moulding a particulate, carbonatable material that contains water and by carbonating the obtained compact with carbon dioxide gas. In order to be able to ensure an optimal compressive strength of the article two types of tests are provided. In the first type of test a sample of the particulate material is compressed with an increasing compaction pressure and when water starts to be expelled from the material as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is at least 7 MPa smaller than this compaction pressure. In the second type of test different samples of the particulate material are press-moulded with different compaction pressures and, after having released the compaction pressure, the density of the compact is determined. In case this density decreases instead of increases as from a particular compaction pressure, the press-moulding step is performed with a compaction pressure which is smaller than this particular compaction pressure.