CEMENTITIOUS BINDER COMPOSITION COMPRISING Si-SLAG AND CaCO 3-SOURCE

Abstract

A cementitious binder composition for a concrete, grout or mortar, comprising: (A) At least 5.0 wt.% but less than 60.0 wt.% of a Si-Slag comprising at least 4.0 wt.% of MnO, at least 15.0 wt.% of CaO, and at least 7.5 wt.% of Al2O3, with reference to the weight of the Si-Slag; (B) At least 1.0 wt.% but less than 50.0 wt.% of a CaCO3-source, wherein said CaCO3-source has a mass-median diameter value (D50) of at most 30.0 µm, wherein the CaCO3-source (B) has a CaCO3 content of at least 20.0 wt.%; and (C) at least 5.0 wt.% but less than 90 wt.% of a cement, wherein said cementitious binder composition has a CaCO3 content of at least 1.0 wt.% but less than 50.0 wt.%, preferably less than 30.0 wt.% with reference to the total weight of said binder composition.

Description

CEMENTITIOUS BINDER COMPOSITION COMPRISING Si-SLAG AND CaCO3- SOURCETechnical Field

[0001] The present invention relates to the field of cement-based binder, in particular a cementitious binder composition for a concrete, grout or mortar. The present invention further relates to a mortar, grout or concrete composition comprising said cementitious binder composition as well as processes for obtaining said cementitious binder composition and a premix for said cementitious binder composition.Background Art

[0002] Thanks to its high versatility and durability, as well as relatively low price, concrete has become one of the most commonly used construction materials worldwide. However, its production, mainly through Ordinary Portland Cement (OPC) manufacturing, contributes significantly to environmental issues, causing up to 8% of global CO2 emissions. It is estimated that in 2023, around 785 kg CO2eq was emitted per metric ton of cement produced (https: / / cembureau.eu / media / kuxd32gi / cembureau- 2050-roadmap_final-version_web.pdf). With increasing demand for construction materials, there is a growing need to address these environmental impacts. Strategies include improving energy efficiency, exploring alternative materials, and adopting carbon capture technologies (Yang et al., https: / / doi.Org / https: / / doi.org / 10.1016 / j.jclepro.2014.03.018).

[0003] Supplementary Cementitious Materials (SCMs) are widely used in cement and concrete as partial replacement of clinker (CEM I) in binder material, thereby reducing the carbon footprint of concrete. SCMs encompass various inorganic materials that contribute to the properties of concrete. These materials can be categorized as inert, latent hydraulic, or pozzolanic. Inert SCMs (e.g. milled limestone) serve as fillers, filling voids and promoting microstructural densification in cement-based products. Latent hydraulic SCMs, such as those rich in calcium and silicon oxides (e.g. ground granulated blast furnace slag (GGBFS herein after)), undergo a reaction with water to produce calcium-silicate hydrate (C-S-H) or calcium-aluminum-silicate hydrate (C-A-S-H) gels when the pH is high enough (for example, in the presence of OPC). The pozzolanic reaction occurs when pozzolans, which are siliceous or siliceous aluminous materials (e.g. fly ash from coal energy plants) lacking inherent cementitious properties, interact with cement, consuming Ca(OH)2 generated during hydration and resulting in theformation of C-S-H and C-A-S-H gels and microstructural densification.

[0004] GGBFS and fly ash constitute the most used SCMs and have been defined in compositions in the cement European standard EN 197-1 (2011). However, stricter environmental regulations have led to closures of coal combustion plants in Europe, reducing the availability of coal fly ash in regions like the Benelux (https: / / www.greenpeace.org / belgium / nl / story / 1334 / belgie-neemt-definitief-afscheid- van-steenkool / ). Meanwhile, many blast furnaces in the Ell are nearing the end of their lifespans, potentially leading to shortages of GGBFS. Greener alternatives such as Direct Reduction-Electric Arc Furnace (DR-EAF) are being explored to replace conventional blast furnaces. To achieve carbon neutrality in iron steelmaking, hydrogen direct reduction is also under investigation. Both alternatives do not produce blast furnace slags. These shifts in the industry landscape, coupled with increasing demand for SCMs in countries like China and India, are exacerbating the scarcity of GGBFS and fly ash, prompting the search for alternative SCMs (https: / / www.concrete4change.com / pressrelease / barriers-to-net-zero-concrete-fly-ash- and-granulated-blast-furnace-slag-shortage / ).

[0005] Amongst the alternatives to GGBFS and fly ash, calcined clays have gained increasing attention in the recent years. Clays are widely abundant around the world and the heating step necessary to make them reactive does not release any chemically bounded CO2 and is done at relatively low temperatures (650 - 850°C) compared to clinker production (1450°C) (Snellings et al., https: / / doi.Org / 10.2138 / rmg.2012.74.6). The LC3 system (Limestone Calcined Clay Cement) constitutes a promising way to make use of calcined clays through their combination with milled limestone and OPC. The three primary components (i.e. clinker, calcined clay, and limestone) enable high clinker replacement rates and result in a refined and interconnected microstructure (Antoni et al., https: / / doi.Org / https: / / doi.org / 10.1016 / j.cemconres.2012.09.006). Despite this advantage, the LC3 systems present some challenges, the technology is still fully based on depleting primary raw materials and relies on the local availability of medium to high purity clay deposits. While it has a lower footprint compared to the clinker production, a large amount of energy is still required to calcine the clay materials (accounting for about 200 - 400kg CO2 per ton of calcined clay (Martinez et al, DOI 10.1088 / 2515- 7620 / acccd8). A change of infrastructure and, consequently, large investments in calcination plants are also required. Regarding the control of the rheology, it is challenging (Abdulqader et al., https: / / doi.Org / https: / / doi.org / 10.1016 / j.jmrt.2023.06.114) due to the high-water demand of the calcined clays, which requires to either increase thewater to binder ratio (impacting in turn the strength and durability of the concrete) or use large amounts of superplasticizers (increasing the price).

[0006] Additionally, the combination of GGBFS with, amongst others, so-called “fine” fillers has been reported. The reported inventions rely specifically on strong water reducers to obtain an improved mechanical performance (EP 4 082 988 A1) or on the combination of an activator and a strong water reducer (EP 4 082 984 A1).

[0007] Other inventions report on the use of a manganese residue in concrete applications combining with cement and limestone requiring additionally a steel slag and an activator to have good mechanical performance (CN 102329105 A). Similarly, the composite material including Si-Slag as explained in CN114605123 A requires extra silica fume and CaSO4-whiskers to perform as LIHPC (Ultra High Performance Concrete). Moreover, no further characteristics on the chemistry of the Si-Slag is shared. These documents disclose the use of limestone as a filler without disclosing or suggesting any synergetic effect between the limestone and the silicon-manganese-slag (Si-Slag). Furthermore, CN 115 321 849 B discloses a cement that uses a mix of silicomanganese slag and limestone, which helps reduce the amount of traditional cement needed. However, the silicomanganese slag has a low level of manganese.

[0008] Due to the increasing scarcity of GGBFS and fly ash as well due to the aforementioned disadvantages of calcined clays, some industrial by-products have been identified as having great potential to serve as alternatives for calcined clays, GGBFS and fly ash. One of them is silicon-(manganese) slag (Si-Slag), which is a by-product of certain types of ferroalloys that enhances the mechanical characteristics of steel. These alloys are manufactured through the carbothermic reduction of raw materials within a submerged arc furnace (1600 - 1650°C). This process generates around 1.31 of Si-Slag per ton of alloy (Navarro et al., https: / / doi.Org / https: / / doi.org / 10.1016 / j.conbuildmat.2018.07.093). Despite the higher concentration of MnO and a lower concentration of CaO content, the chemical composition of Si-Slag is relatively close to that of GGBFS. For this reason, some researchers have already used it either blended with clinker or as a precursor for alkali- activated binders. The reactive components of the Si-Slag, like CaO and SiO2, advantageously contribute to the cement gel's binding capability, with no reported leaching of toxic or heavy metals from the Si-Slag-reacted binder matrix.

[0009] However, a wide range of slags, including Si-Slags, has been proven in practice to be of limited use for the replacement for OPC in concrete, grout or mortar compositions, due to the slow and limited reactivity of such compositions comprisingsuch slags within the timeframe of 28 days. This age corresponds to the standard curing time at which the compressive strength of a cementitious material is evaluated and is preferably the highest possible value. The slower hydration kinetics limits the replacement levels and therefore the drive for mortar, concrete and cement producers to use other slags than blast furnace slag. Therefore, in practice, these slag streams, such as Si-Slag, are mostly discarded and the cement and concrete industry relies mainly on primary materials such as calcined clays to achieve a lower ecological footprint.

[0010] Based on the above, there is therefore a need to improve the workability of slags, such as Si-Slags. More in particular, there is a need for compositions, comprising such slags, particularly said Si-Slags, wherein such compositions dispose of a sufficient reactivity to be able to cure into a concrete, grout or mortar within the timeframe of 28 days.Summary of the invention

[0011] The inventors have surprisingly found that the composition according to the present invention fulfills the above mentioned needs and overcomes the above mentioned disadvantages.

[0012] For the above purpose, the invention is directed to a cementitious binder composition for a concrete, grout or mortar, said cementitious binder composition comprising or consisting of:(A) at least 5.0 wt.% with reference to the total weight of said binder composition, preferably at least 10 wt.% with reference to the total weight of said binder composition, more preferably at least 15.0 wt.% with reference to the total weight of said binder composition, but less than 60.0 wt.% with reference to the total weight of said binder composition, preferably less than 50.0 wt.% with reference to the total weight of said binder composition of a Si-Slag, wherein the Si-Slag has at least 4.0 wt.% of MnO with reference to the weight of the Si-Slag, at least 15.0 wt.% of CaO with reference to the weight of the Si-Slag and at least 7.5 wt.% of AI2O3 with reference to the weight of the Si-Slag, preferably said Si-Slag being at least 30.0 wt.% amorphous, preferably glassy; and(B) optionally, at least 1.0 wt.% with reference to the total weight of said binder composition, preferably at least 2.0 wt.% with reference to the total weight of said binder composition, more preferably at least 4.0 wt.% with reference to the total weight of said binder composition, even more preferably at least 6.0 wt.% withreference to the total weight of said binder composition, but less than 50.0 wt.% with reference to the total weight of said binder composition, preferably less than 35.0 wt.% with reference to the total weight of said binder composition of a CaCCh- source, wherein said CaCCh-source (B) has a D50 value of at most 30.0 pm, and wherein the CaCCh-source (B) has a CaCCh content of at least 20.0 wt.%, preferably at least 40.0 wt.% with reference to the total weight of the CaCCh-source; and(C) at least 5.0 wt.% with reference to the total weight of said binder composition, preferably at least 10.0 wt.% with reference to the total weight of said binder composition, more preferably at least 15.0 wt.% with reference to the total weight of said binder composition, but less than 90.0 wt.% with reference to the total weight of said binder composition, preferably less than 75.0 wt.% with reference to the total weight of said binder composition of a cement, preferably said cementitious binder composition having a CaCCh content of at least 1.0 wt.% with reference to the total weight of said binder composition, preferably at least 5.0 wt.% with reference to the total weight of said binder composition, but less than 50.0 wt.% with reference to the total weight of said binder composition, preferably less than 30.0 wt.% with reference to the total weight of said binder composition.

[0013] According to specific embodiments of the invention, the cementitious binder composition comprises one or more of the following technical features:• the Si-Slag (A) has a D50 value of at most 30.0 pm, preferably at most 10.0 pm;• the Si-Slag (A) and / or the cement (C) comprises CaCCh issued from a different source than the CaCChfrom the CaCCh-source (B);• the cementitious binder composition for a concrete, grout or mortar according any one of the preceding claims, wherein the cement is:- an Ordinary Portland cement (OPC), in particular Portland cement (OEM I according to EN 197-1 (2011)), or- a Blended cement, in particular is selected from the group consisting of Portland composite cement (OEM II as EN 197-1 (2011)), blast furnace slag cement (OEM III as EN 197-1 (2011)), pozzolan cement (OEM IV as EN 197-1 (2011)), slag- pozzolanic cement (OEM V as EN 197-1 (2011)), composite cement (such as OEM ll / C (LL,S) and OEM VI as EN 197-5 (2021)), cement with recycle building materials (OEM II and OEM VI as EN 197-6 (2023)), and combinations thereof, or- a combination of the Ordinary Portland cement and the Blended cement;• said Si-Slag (A) has a composition further comprising SiC>2 and MgO, wherein the weight ratio SiC>2 / (CaO+MgO) in said Si-Slag (A) is at least 0.8, preferably at least 0.9, more preferably at least 1.0;• the weight ratio of the AI2O3 content of the Si-Slag (A) to the MnO content of Si- Slag (A) is larger than 1.0;• the weight ratio of the Si-Slag (A) to the CaCCh-source (B), meaning (A) : (B), is at least 1.0:4.0, preferably at least 1.0:2.0, more preferably at least 1.0: 1.0, even more preferably at least 2.0:1.0;• the weight ratio of the Si-Slag (A) and the CaCCh-source (B) to the cement (C), meaning ((A)+(B)):(C)), is at least 1.0:19.0, preferably at least 1.0:5.0, more preferably at least 1.0:1 .0;• said cementitious binder composition further comprises at least 0.5 wt.% with reference to the total weight of said binder composition but less than 10.0 wt.%, preferably less than 20.0 wt.% with reference to the total weight of said binder composition of a CaSC>4-source (D), and wherein the CaSC>4-source (D) has a CaSC>4 content of at least 20.0 wt.%, preferably at least 45.0 wt.% with reference to the total weight of the CaSC>4-source, and wherein the CaSC>4-source comprises one or more of the following:- CaSC>4 (anhydrite),- alfa-CaSO4.3 H2O (alfa hemi-hydrate),- beta-CaSO4.3 H2O (beta hemi-hydrate),- CaSC>4.2H2O (gypsum),- CaSC>4.2H2O (phosphogypsum),- SCh-scrubber gypsum;• the Si-Slag is at least 30.0 wt.%, preferably at least 40.0 wt.%, more preferably at least 50.0 wt.%, and even more preferably at least 60.0 wt.% amorphous, preferably glassy, with reference to the total weight of the Si-Slag;• the Si-Slag (A) has one or more of the following characteristics:- at least 17.0 wt.%, preferably at least 20.0 wt.%, more preferably at least 21.0 wt.%, even more preferably at least 22.0 wt.% of CaO, with respect to the total weight of the Si-Slag;- at most 40.0 wt.%, preferably at most 38.0 wt.%, more preferably at most 35.0 wt.%, even more preferably at most 33.0 wt.%, still more preferably at most 30.0 wt.% of CaO, with respect to the total weight of the Si-Slag;- at least 2.0 wt.%, preferably at least 3.0 wt.%, more preferably at least 3.5 wt.%, even more preferably at least 4.0 wt.%, still more preferably at least 4.5 wt.% of MgO, with respect to the total weight of the Si-Slag;- at most 13.0 wt.%, preferably at most 12.0 wt.%, more preferably at most 11.0 wt.%, even more preferably at most 10.5 wt.%, still more preferably at most 10.0 wt.%, most preferably at most 9.5 wt.% of MgO, with respect to the total weight of the Si-Slag;- at least 9.0 wt.%, preferably at least 11.0 wt.%, more preferably at least 12.0 wt.%, still more preferably at least 13.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag;- at most 30.0 wt.%, preferably at most 28.0 wt.%, more preferably at most 25.0 wt.%, even more preferably at most 23.0 wt.%, still more preferably at most 20.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag;- at least 20.0 wt.%, preferably at least 22.0 wt.%, more preferably at least 25.0 wt.%, even more preferably at least 27.0 wt.%, still more preferably at least 30.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag;- most 50.0 wt.%, preferably at most 48.0 wt.%, more preferably at most 45.0 wt.%, even more preferably at most 43.0 wt.%, still more preferably at most 40.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag;- at least 0.1 wt.%, preferably at least 0.2 wt.%, more preferably at least 0.3 wt.% of Fe2C>3, with respect to the total weight of the Si-Slag;- at most 10.0 wt.%, preferably at most 7.0 wt.%, more preferably at most 5.0 wt.%, even more preferably at most 2.0 wt.%, still more preferably at most 1 .0 wt.% of Fe2C>3, with respect to the total weight of the Si-Slag;- at least 6.0 wt.%, preferably at least 7.0 wt.%, more preferably at least 8.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag;- at most 22.0 wt.%, preferably at most 20.0 wt.%, more preferably at most 18.0 wt.%, even more preferably at most 16.0 wt.%, still more preferably at most 14.0 wt.%, most preferably at most 12.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag;- a (mass-median-diameter) D50 value smaller than 25 pm, preferably smaller than 20 pm, more preferably smaller than 15 pm;• the CaCOa-source (B) comprises one or more of the following characteristics- at least 20.0 wt.% of carbonates, preferably at least 40.0 wt.% of carbonates, more preferably at least 60.0 wt.% of carbonates;- a CaCCh content of at least 60.0 wt.% of CaCCh with respect to the total weight of the CaCOs-source;• the CaCOa-source has one or more of the following characteristics:- a (mass-median-diameter) D50 value smaller than 25 pm, preferably smaller than 20 pm, more preferably smaller than 15 pm, still more preferably smaller than 10 pm;- a Dmax value smaller than 63 pm, preferably smaller than 50 pm, more preferably smaller than 45 pm;• said cementitious binder composition further comprises at least 2.0 wt.% with reference to the total weight of said binder composition but less than 50.0 wt.% with reference to the total weight of said binder composition of a ground granulated blast-furnace slag (GGBFS)(E);• said cementitious binder composition further comprises a flow improving agent (F), which agent is preferably selected from the list consisting of a naphthalene- based superplasticizer; a lignosulfonate; a protein, such as casein; a naphthalene sulphonate; a melamine-based superplasticizer; a polycarboxylate ether (PCE) or polyacrylate ether (PAE) based superplasticizer, a salt or derivative thereof; and mixtures thereof;• said cementitious binder composition further comprises at least 2.0 wt.% with reference to the total weight of said binder composition but less than 50.0 wt.% with reference to the total weight of said binder composition of a binding compound (G);• the binding compound (G) is selected from the list consisting of an ash, a clay, a calcined clay, a distinct metallurgical slag, a mine tailing, a quartz filler, bauxite residue, and mixtures thereof;• the CaCOs-source (B) is different from the Si-Slag (A);• the CaCOs-source (B) is different from the cement (C);• the Si-Slag (A) being different from the cement (C).

[0014] For the above purpose, the invention is also directed to a mortar, concrete or grout composition comprising the cementitious binder composition, and at least oneof aggregate, water, sand and gravel.

[0015] For the above purpose, the invention is also directed to a process to obtain the cementitious binder composition, the process comprising the steps of:- providing the Si-Slag (A);- optionally providing the CaCCh source (B);- providing the cement (C);- optionally providing one or more compounds selected from the group comprising: the CaSC>4-source (D), the ground granulated blastfurnace slag (E), flow improving agent (F) and the binding compound (G);- mixing the Si-Slag, optionally the CaCCh-source (B) and the cement (C) and optionally the one or more compounds selected from the group comprising: the CaSC>4-source (D), the ground granulated blastfurnace slag (E), flow improving agent (F) and the binding compound (G).

[0016] For the above purpose, the invention is also directed to a process for the manufacturing of a premix for the cementitious binder composition, comprising the steps of:- providing the Si-Slag (A);- providing the CaCCh-source (B);- mixing the Si-Slag (A), with the CaCCh-source (B) to form said premix.

[0017] For the above purpose, the invention is also directed to a process for the manufacturing of the cementitious binder composition , said process comprises the step of- optionally providing the cement (C);- optionally providing the premix obtained with the process for the manufacturing of the premix;- optionally providing one or more compounds selected from the group comprising: the CaSC>4-source (D), the ground granulated blastfurnace slag (E), flow improving agent (F) and the binding compound (G);- mixing the premix obtained with the process for the manufacturing of the premix with the cement (C) and optionally the one or more compounds selected from the group comprising: the CaSC>4-source(D), the ground granulated blast-furnace slag (E), flow improving agent (F) and the binding compound (G), to form the cementitious binder composition.

[0018] For the above purpose, the invention is also directed to a use of a cementitious binder composition according to the invention for producing a mortar, grout or concrete composition.

[0019] For the above purpose, the invention is also directed to a cementitious binder precursor composition for a cementitious binder composition for a concrete, grout or mortar, said cementitious binder precursor composition comprising or consisting of:(A) at least 7.0 wt.% with reference to the total weight of said precursor composition but less than 85.0 wt.% with reference to the total weight of said precursor composition, preferably less than 70.0 wt.% with reference to the total weight of said precursor composition of a Si-Slag comprising at least 4.0 wt.% of MnO with reference to the weight of the Si-Slag, at least 15.0 wt.% of CaO with reference to the weight of the Si-Slag and at least 7.5 wt.% of AI2O3 with reference to the weight of the Si-Slag, preferably said Si-Slag being at least 30.0 wt.% amorphous, preferably glassy;(B) at least 2.0 wt.% with reference to the total weight of said precursor composition but less than 70.0 wt.% with reference to the total weight of said precursor composition of a CaCCh-source, and wherein said CaCCh- source has a D50 value of at most 30 pm, wherein the CaCCh-source (B) has a CaCCh content of at least 20.0 wt.% with reference to the total weight of the CaCOs-source, preferably at least 40.0 wt.% with reference to the total weight of the CaCOs-source, preferably said cementitious binder precursor composition having a CaCCh content of at least 1.0 wt.% with reference to the total weight of said precursor composition but less than 35.0 wt.% with reference to the total weight of said precursor composition, preferably less than 20.0 wt.% with reference to the total weight of precursor composition.

[0020] According to specific embodiments of the invention, the cementitious binder precursor composition comprises one or more of the following technical features:• said Si-Slag (A) has a D50 value of at most 30pm, preferably at most 10 pm;• the Si-Slag (A) and / or the cement (C) comprises CaCCh issued from a different source than the CaCCh from the CaCCh-source (B);• said Si-Slag (A) has a composition further comprising SiC>2 and MgO, wherein the weight ratio SiC>2 / (CaO+MgO) in said Si-Slag (A) is at least 0.8, preferably at least 0.9, more preferably at least 1.0;• the weight ratio of the AI2O3 content of the Si-Slag (A) to the MnO content of Si- Slag (A) is larger than 1.0;• the weight ratio of the Si-Slag (A) to the CaCCh-source (B), meaning (A) : (B), is at least 1.0:4.0, preferably at least 1.0:2.0, more preferably at least 1.0:1.0, even more preferably at least 2.0:1.0;• said cementitious precursor composition further comprises at least 1.0 wt.% with reference to the total weight of said precursor composition but less than 30.0 wt.%, preferably less than 15.0 wt.% with reference to the total weight of said precursor composition of a CaSC>4-source (D), and wherein the CaSC>4-source (D) has a CaSC>4 content of at least 20.0 wt.%, preferably at least 45.0 wt.% with reference to the total weight of the CaSC>4-source (D), and wherein the CaSC>4- source (D) comprises one or more of the following:- CaSC>4 (anhydrite),- alfa-CaSO4.3 H2O (alfa hemi-hydrate),- beta-CaSO4.3 H2O (beta hemi-hydrate),- CaSC>4.2H2O (gypsum),- CaSC>4.2H2O (phosphogypsum),- SCh-scrubber gypsum• the Si-Slag (A) and / or the CaCCh-source (B) comprises CaSOt from a different source than the CaSOtfrom the CaSC>4-source (D).• said cementitious binder precursor composition further comprises at least 3.0 wt.% with reference to the total weight of said precursor composition but less than 65.0 wt.% with reference to the total weight of said precursor composition of a ground granulated blast-furnace slag (GGBFS);• the Si-Slag (A) has one or more of the following characteristics:- at least 17.0 wt.%, preferably at least 20.0 wt.%, more preferably at least 21.0 wt.%, even more preferably at least 22.0 wt.% of CaO, with respect to the total weight of the Si-Slag;- at most 40.0 wt.%, preferably at most 38.0 wt.%, more preferably at most 35.0 wt.%, even more preferably at most 33.0 wt.%, still more preferably at most 30.0 wt.% of CaO, with respect to the total weight of the Si-Slag;- at least 2.0 wt.%, preferably at least 3.0 wt.%, more preferably at least 3.5 wt.%, even more preferably at least 4.0 wt.%, still more preferably at least 4.5 wt.% of MgO, with respect to the total weight of the Si-Slag;- at most 13.0 wt.%, preferably at most 12.0 wt.%, more preferably at most 11.0 wt.%, even more preferably at most 10.5 wt.%, still more preferably at most 10.0 wt.%, most preferably at most 9.5 wt.% of MgO, with respect to the total weight of the Si-Slag;- at least 7.5 wt.%, preferably at least 9.0 wt.%, more preferably at least 11.0 wt.%, even more preferably at least 12.0 wt.%, still more preferably at least 13.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag;- at most 30.0 wt.%, preferably at most 28.0 wt.%, more preferably at most 25.0 wt.%, even more preferably at most 23.0 wt.%, still more preferably at most 20.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag;- at least 20.0 wt.%, preferably at least 22.0 wt.%, more preferably at least 25.0 wt.%, even more preferably at least 27.0 wt.%, still more preferably at least 30.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag;- most 50.0 wt.%, preferably at most 48.0 wt.%, more preferably at most 45.0 wt.%, even more preferably at most 43.0 wt.%, still more preferably at most 40.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag;- at least 0.1 wt.%, preferably at least 0.2 wt.%, more preferably at least 0.3 wt.% of Fe2C>3, with respect to the total weight of the Si-Slag;- at most 10.0 wt.%, preferably at most 7.0 wt.%, more preferably at most 5.0 wt.%, even more preferably at most 2.0 wt.%, still more preferably at most 1 .0 wt.% of Fe2C>3, with respect to the total weight of the Si-Slag;- at least 6.0 wt.%, preferably at least 7.0 wt.%, more preferably at least 8.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag;- at most 22.0 wt.%, preferably at most 20.0 wt.%, more preferably at most 18.0 wt.%, even more preferably at most 16.0 wt.%, still more preferably at most 14.0 wt.%, most preferably at most 12.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag;- a (mass-median-diameter) D50 value smaller than 25.0 pm, preferably smaller than 20.0 pm, more preferably smaller than 15.0 pm;• the CaCOa-source (B) comprises one or more of the following characteristics:- at least 20.0 wt.% of carbonates, preferably at least 40.0 wt.% of carbonates, more preferably at least 60.0 wt.% of carbonates;- a CaCCh content of at least 60.0 wt.% of CaCCh with respect to the total weight of the CaCOs-source (B);• the CaCOa-source (B) has one or more of the following characteristics:- a (mass-median-diameter) D50 value smaller than 25.0 pm, preferably smaller than 20.0 pm, more preferably smaller than 15.0 pm, even more preferably smaller than 10 pm;- a Dmax value smaller than 63.0 pm, preferably smaller than 50.0 pm, more preferably smaller than 45.0 pm.

[0021] For the above purpose, the invention is also directed to a process for the manufacturing of the cementitious binder precursor composition for a cementitious binder composition for a concrete, grout or mortar, comprising the steps of:- providing the Si-Slag (A);- providing the CaCCh-source (B);- Mixing the Si-Slag (A), with the CaCCh-source (B) to form said cementitious binder precursor composition.Brief description of the figures

[0022] These and other features and advantages of embodiments of the present invention will now be described in more detail with reference to the accompanying drawings, in which:

[0023] Figure 1 illustrates compressive strength development for mortar compositions having a varying Si-Slag concentration, at a constant OPC concentration.

[0024] Figure 2 illustrates compressive strength development for mortar compositions having a varying GGBFS concentration, at a constant OPC concentration.

[0025] Figure 3 illustrates compressive strength development for mortar compositions comprising different types of Si-Slag.

[0026] Figure 4 illustrates compressive strength development for mortar compositions with a varying OPC (CEM I) content.

[0027] Figure 5 illustrates compressive strength development for mortarcompositions with and without CaSC

[0028] Figure 6 illustrates compressive strength development for mortar compositions in comparison with calcined clay.

[0029] Figure 7 illustrates the slump flow for similar mortar composition containing Si-Slag or calcined clay.

[0030] Figure 8 illustrates compressive strength development for mortar compositions having a constant OPC (CEM I) content with a varying fly ash concentration.Detailed description of the invention

[0031] The present invention will be described with respect to particular embodiments and with reference to certain figures, but the invention is not limited thereto but only by the claims.

[0032] In the context of the present invention, the term “comprising” should not be interpreted as excluding features or elements other than those explicitly mentioned. It should be construed as specifying the presence of the features or elements indicated, but does not exclude the presence or addition of one or more other features or elements. Thus, the scope of the expression "a product comprising A and B" should not be limited to products consisting only of A and B. Similarly, a composition comprising components A and B should not be limited to compositions consisting only of components A and B. Accordingly, the terms "comprising" and "including" encompass the terms more restrictive “consisting essentially of’ and “consisting of”.

[0033] In the context of the present invention, if an element or component is said to be selected from a list of recited elements or components, it should be understood that the element or component can also be any one of the individual recited elements or components in said list, or can also be selected from a group consisting of any two or more of the explicitly listed elements or components.

[0034] Further advantages and characteristics of the invention will become apparent from the following description. However, the following description is merely illustrative and is not intended to limit the scope of the invention as determined by the claims.

[0035] An aspect of the invention relates to a cementitious binder composition for a concrete, grout or mortar, comprising a Si-Slag (A), a CaCCh-source (B) and a cement (C) like an Ordinary Portland Cement (OPC).

[0036] The invention is inter alia based on the insight that the combination of a Si- Slag and a CaCCh-source, allows to partially replace OPC in a concrete, grout or mortar composition, wherein said combination allows to produce a concrete, grout or mortar having a significantly higher compressive strength in comparison with compositions containing only one of these two compounds as a replacement for OPC. In other words, the invention is inter alia based on the unexpected positive and synergistic effect on compressive strength between the Si-Slag and the CaCOs-source, in their use as SCMs. Advantageously, the compositions according to the present invention have been found to lead to concretes, grouts and mortars, achieving appropriate levels of compressive strength within the required time frame, i.e. 28 days. The compositions further allow for the fabrication of a robust binder with low CO2 footprint at economical scale. Moreover, the obtained binder allows a similar workability as in conventional concrete and can be used as replacement for conventional blended cement types. The used infrastructure is the same or substantially the same as in a conventional cement plant. The milling of the Si-Slag may require some adaptations. However, due to the use of abundant and easily millable limestone, it allows for fast and larger scale implementation.

[0037] The following terms are provided solely to aid in the understanding of the invention.

[0038] For the purpose of the invention, the term “binder” or “binder composition” refers to a composition or mixture of compounds or materials that holds or draws other materials together to form a cohesive whole mechanically. The binder composition preferably has this effect due to the addition of water. Herein, the term is used to describe such properties for the production of a concrete, grout or mortar, which is obtained upon combining such a binder composition with at least one of water, sand, and / or aggregate. Traditionally, the most frequent used binder for the production of concrete, grout or mortar is Ordinary Portland Cement (CEM I).

[0039] For the purpose of the invention, the term “slag” refers herein to a by-product material produced during the smelting or refining of metals, which typically occurs by reaction of a flux with impurities. Slags as referred herein can advantageously be used to at least partially replace OPC in an inorganic composition for the purpose of making concrete, grout or mortar.

[0040] For the purpose of the invention, the term “cement” refers herein to a binding material for use in concrete, grout or mortar. The cement may be any type of cement: - an Ordinary Portland cement (OPC), in particular Portland cement (CEM I) according to EN 197-1 (2011), or- a Blended cement, in particular is selected from the group consisting of Portland composite cement (CEM II as EN 197-1 (2011)), blast furnace slag cement (CEM III as EN 197-1 (2011)), pozzolan cement (CEM IV as EN 197-1 2011), slag-pozzolanic cement (CEM V as EN 197-1 2021), composite cement (such as CEM ll / C-M (LL,S) and CEM VI as EN 197-5 (2021)), cement with recycle building materials (CEM II and CEM VI as EN 197-6 (2023)), and combinations thereof, or- a combination of the Ordinary Portland cement and the Blended cement.

[0041] In embodiments, the cement is preferably an Ordinary Portland cement (OPC). More preferably, said cement relates herein to CEM I, according to EN 197-1 (2011). Preferably the Ordinary Portland cement is composed for at least two thirds in mass of calcium silicates [3CaO.SiO2] and [2CaO.SiO2] (a.k.a. alite (C3S) and belite (C2S)), the remaining part comprising preferably AI2O3 and Fe2O3 - containing phases.

[0042] For the purpose of the invention, the term “D50” refers herein to a mass- median-diameter, which relates to the particle diameter for which half of the particle mass is contained in smaller particles and half is contained in larger particle diameters. The term “Dmax” relates to the maximum particle size of a particle population.

[0043] For the purpose of the invention, the term “CaCOs-source” refers to any source containing calcium carbonate. In embodiments, CaCCh-source can relate to a primary source such as limestone, or secondary sources such as carbonated cement paste. This also includes minerals where calcium and a carbonate group are combined with other elements such as in the case of dolomite CaMg(CC>3)2.

[0044] The invention is based on the combination of a specific slag, Si-Slag, with a source of calcium carbonate, preferably finely ground, and OPC. This blend of three distinct compounds results in binder material composition which has an unexpected relatively high compressive strength after 28 days.

[0045] According to the invention, the cementitious binder composition for a concrete, grout or mortar comprises a Si-Slag. Preferably, the cementitious binder composition comprises at least one type of a Si-Slag.

[0046] Typically, said Si-Slag will originate as a by-product from the manufacturing of a ferromanganese or ferromanganese-silicon alloy, usually by reducing a manganese ore in a submerged arc furnace.

[0047] In embodiments according to the invention, said Si-Slag comprises at least 15.0 wt.%, preferably at least 17.0 wt.%, more preferably at least 20.0 wt.%, even more preferably at least 21.0 wt.%, and still more preferably at least 22.0 wt.% of CaO, withrespect to the total weight of the Si-Slag. It will further be understood that the Si-Slag comprises at most 40.0 wt.%, preferably at most 38.0 wt.%, more preferably at most 35.0 wt.%, even more preferably at most 33.0 wt.%, and still more preferably at most 30.0 wt.% of CaO, with respect to the total weight of the Si-Slag.

[0048] In embodiments according to the invention, said Si-Slag comprises at least 2.0 wt.%, preferably at least 3.0 wt.%, more preferably at least 3.5 wt.%, even more preferably at least 4.0 wt.%, and still more preferably at least 4.5 wt.% of MgO, with respect to the total weight of the Si-Slag. It will further be understood that the Si-Slag comprises at most 13.0 wt.%, preferably at most 12.0 wt.%, more preferably at most 11.0 wt.%, even more preferably at most 10.5 wt.%, still more preferably at most 10.0 wt.%, and most preferably at most 9.5 wt.% of MgO, with respect to the total weight of the Si- Slag.

[0049] In embodiments according to the invention, said Si-Slag comprises at least 7.5 wt.%, preferably at least 9.0 wt.%, more preferably at least 11.0 wt.%, even more preferably at least 12.0 wt.%, and still more preferably at least 13.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag. It will further be understood that the Si-Slag comprises at most 30.0 wt.%, preferably at most 28.0 wt.%, more preferably at most 25.0 wt.%, even more preferably at most 23.0 wt.%, and still more preferably at most 20.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag.

[0050] In embodiments according to the invention, said Si-Slag comprises at least 20.0 wt.%, preferably at least 22.0 wt.%, more preferably at least 25.0 wt.%, even more preferably at least 27.0 wt.%, and still more preferably at least 30.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag. It will further be understood that the Si-Slag comprises at most 50.0 wt.%, preferably at most 48.0 wt.%, more preferably at most 45.0 wt.%, even more preferably at most 43.0 wt.%, and still more preferably at most 40.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag.

[0051] In embodiments according to the invention, said Si-Slag comprises at least 0.1 wt.%, preferably at least 0.2 wt.%, and more preferably at least 0.3 wt.% of Fe2Os, with respect to the total weight of the Si-Slag. It will further be understood that the Si- Slag comprises at most 10.0 wt.%, preferably at most 7.0 wt.%, more preferably at most 5.0 wt.%, even more preferably at most 2.0 wt.%, and still more preferably at most 1.0 wt.% of Fe2C>3, with respect to the total weight of the Si-Slag.

[0052] In embodiments according to the invention, said Si-Slag comprises at least 4.0 wt.%, preferably at least 6.0 wt.%, more preferably at least 7.0 wt.%, and even morepreferably at least 8.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag. It will further be understood that the Si-Slag comprises at most 22.0 wt.%, preferably at most 20.0 wt.%, more preferably at most 18.0 wt.%, even more preferably at most 16.0 wt.%, still more preferably at most 14.0 wt.%, and most preferably at most 12.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag. It will be known to the skilled in the art that manganese can exhibit oxidation states from II to VII, which can be present in the Si-Slag. For this reason, the concentrations herein are expressed as MnO.

[0053] In embodiments according to the invention, the weight ratio SiO2 / (CaO+MgO) is at least 0.8. Preferably, said ratio is at least 0.9; more preferably said ratio is at least 1.0.

[0054] Preferably, the Si-Slag exists for a majority of amorphous phase, preferably glassy phase. It has been observed that the amorphous phase, preferably glassy phase, is more susceptible to dissolve in alkaline environment and will therefore advantageously result in a higher compressive strength development at a faster rate. In order to obtain a large fraction of amorphous glass-content, the Si-Slag is preferably cooled at a high rate. However, due to the nature of the slag, the Si-Slag can still have a significant amount of amorphous (glassy) material, even when slowly cooled. The granulation of the slag, with water or air, will lead to a preferred increase in amorphous, preferably glassy fraction. A granulation with water allows to enhance the level of glassy phase, as water permits a faster quenching.

[0055] In embodiments according to the invention, the Si-Slag is at least 30.0 wt.%, preferably at least 40.0 wt.%, more preferably at least 50.0 wt.%, and even more preferably at least 60.0 wt.% is amorphous, preferably glassy, with reference to the total weight of the Si-Slag.

[0056] In embodiments according to the invention, the Si-Slag contains only a minority of mineral phases. Preferably, the total of said mineral phases form 50.0 wt.% or less than 50.0 wt.%, preferably less than 40.0 wt.%, more preferably less than 30.0 wt.%, and even more preferably less than 20.0 wt.% of the Si-Slag. The mineral phases may contain at least one of diopside, quartz, gehlenite, alabandite, mavlyanovite, graphite, and / or anorthite.

[0057] Moreover, preferably, the maximal metallic phase content in the Si-Slag is less than 5.0 wt.%, more preferably less than 3.0 wt.%, even more preferably less than 1.0 wt.%. Advantageously, this will facilitate the milling.

[0058] In preferred embodiments according to the invention, said Si-Slag is comminuted (e.g. milled, ground and / or crushed) prior to use in said cementitious binder composition. This can be done, but is not limited to, conventional milling techniques such as by use of a ball mill (BM), a vertical roller miller (VRM) or a high-pressure grinding rolls mill (HPRG). The fineness, being a parameter indicating a particle size, of the ground Si-Slag can be expressed in terms of particle size distribution (PSD). The mass- median-diameter, (D50), is preferably used as the preferred parameter for expressing the particle fineness.

[0059] Preferably, said Si-Slag relates to a powdery material, having a mass- median-diameter D50 value smaller than 30.0 pm, more preferably smaller than 25.0 pm, even more preferably smaller than 20.0 pm, still more preferably smaller than 15.0 pm, and most preferably smaller than 10.0 pm.

[0060] According to the invention, the cementitious binder composition for a concrete, grout or mortar comprises a CaCOs-source. Preferably, the CaCCh-source is a primary material such as milled limestone or limestone flour. Alternatively, the CaCCh- source is a secondary material from demolition wastes such as hardened concrete or cement paste. Such secondary materials contain CaCCh due to the nature of the aggregates or filler present or due to the natural or accelerated carbonation of C-S-H- gel, C-A-S-H-gel or tobermorite-like minerals.

[0061] In other embodiments, said CaCCh-source relates to carbonated slags or ashes. The CaCCh-source can also relate to or originate from carbonated refractory materials.

[0062] The CaCCh-source can also relate to mixed carbonates, such as dolomite or Ca-magnesite (MgCa(CC>3)2) stone. In embodiments, said CaCCh-source relates to a mixture of the CaCCh-containing materials mentioned here above.

[0063] In embodiments according to the invention, the CaCCh-source contains mineral phases, which mineral phases are at least one of: calcite, vaterite, and / or aragonite. In embodiments, said CaCCh-source contains amorphous CaCCh.

[0064] In embodiments according to the invention, the CaCCh-source contains at least 20.0 wt.% of carbonates, more preferably at least 40.0 wt.% of carbonates, even more preferably at least 60.0 wt.% of carbonates.

[0065] In embodiments according to the invention, the CaCCh-source contains at least 20.0 wt.% of CaCCh, more preferably at least 40.0 wt.% of CaCCh, even more preferably at least 60.0 wt.% of CaCCh.

[0066] In embodiments according to the invention, the CaCCh-source is a fine material in terms of particle size. This can be achieved via, amongst others, milling, grinding or natural weathering.

[0067] In embodiments, the fine CaCCh-source has a mass-median-diameter D50 value smaller than 30.0 pm, preferably smaller than 25.0 pm, more preferably smaller than 20.0 pm, even more preferably smaller than 15.0 pm, and most preferably smaller than 10.0 pm.

[0068] In embodiments, the fine CaCCh-source has a Dmax value smaller than 63.0 pm, preferably smaller than 50.0 pm, and more preferably smaller than 45.0 pm.

[0069] According to the invention, the cementitious binder composition for a concrete, grout or mortar further comprises a cement (C), namely Ordinary Portland Cement (OPC). OPC typically relates to a combination of ground clinker and a fraction of a CaSO4-source as a setting control agent. The clinker is composed of the conventional clinker minerals: alite (C3S), belite (C2S), tricalcium aluminate (C3A) and tetracalcium aluminoferrite (C4AF). The OPC can be present in the form of conventional CEM I as expressed in the EN 197-1.

[0070] According to the invention, the cementitious binder composition for a concrete, grout or mortar further comprises a cement (C), namely a blended cement such as CEM II, CEM III, CEM IV, CEM V or CEM VI according to EN 197-1 , EN-197-5 or EN 197-6.

[0071] In embodiments of the invention, an additional CaSC>4-source is added to the cementitious binder composition. The source of CaSOt can be natural or synthetic such as flue gas desulfurization (FGD) gypsum. More preferably, the CaSC>4-source comprises one or more of the following: CaSC>4 (anhydrite), alfa-CaSO4.3 H2O (alfa hemihydrate), beta-CaSO4.3 H2O (beta hemi-hydrate), CaSO^tW (gypsum), CaSO^tW (phosphogypsum), SCh-scrubber gypsum.

[0072] In one embodiment to the invention, the raw materials of the binder composition are milled together. This co-grinding can facility easier operations where no post blending stage is required.

[0073] The binding compound comprises at least: (A) a Si-Slag, (B) a fine CaCCh- source and (C) OPC. For some embodiments, the sum of compounds (A), (B) and (C) is 100%. The reported wt.% are expressed as weight fraction of the sum of all compounds (A), (B) and (C).

[0074] The Si-Slag is present as at least 5.0 wt.% of the binding compound,preferably at least 10 wt.%, more preferably at least 15.0 wt.%.

[0075] The fine CaCOa-source (B) is at least 1.0 wt.% of the binding compound, preferably at least 2 wt.%, more preferably at least 4.0 wt.%, even more preferably 6% wt.%.

[0076] OPC is at least 5.0 wt.% of the binding compound, preferably at least 10wt.%, more preferably at least 15 wt.%.

[0077] The weight ratio of the Si-Slag (A) to the fine CaCOa-source (B) = (A): (B) is at least 1.0:4.0, preferably at least 1.0:2.0, more preferably at least 1.0: 1.0, even more preferably at least 2.0: 1 .0.

[0078] The weight ratio of the Si-Slag (A) to the fine CaCOa -source (B) = (A) : (B) is at most 19.0:1.0, more preferably at most 14.0:1.0, even more preferably at most 9.0:1.0.

[0079] The weight ratio of the Si-Slag (A) and the fine CaCOa-source (B) to the cement (C), in particular OPC, (C) = ((A)+(B)) : (C)) is at least 1.0:19.0, more preferably at least 1.0:9.0, even more preferably at least 1.0:5.0, even more preferably at least 1.0:1.0.

[0080] The weight ratio of the Si-Slag (A) and the fine CaCOa-source (B) to the cement (C) in particular OPC (C) = ((A)+(B)) : (C)) is at most 19.0:1.0, more preferably at most 9.0:1.0, even more preferably at most 4.0:1.0, even more preferably at most 2.0:1.0.

[0081] In one embodiment of the invention, a distinct source of CaSO4 (D), other than present in the cement (C), in particular OPC, is included in the binding compound. Preferably, the distinct CaSO4-source comprises one or more of the following: CaSO4 (anhydrite), alfa-CaSO4.3 H2O (alfa hemi-hydrate), beta-CaSO4.3 H2O (beta hemihydrate), CaSO4.2H2O (gypsum), CaSO4.2H2O (phosphogypsum), SOa-scrubber gypsum or an other secondary source of containing CaSO4.

[0082] The distinct CaSO4-source can be natural or synthetic such as flue gas desulfurization (FGD) gypsum.

[0083] The distinct CaSO4-source (D) is at least 0.1 wt.% of the binding compound, preferably at least 0.2 wt.%, more preferably at least 0.5 wt.%.

[0084] The weight ratio of the Si-Slag (A) and the fine CaCOa-source (B) to the distinct CaSC>4-source (D) = ((A)+(B)): (D) is at Ieast 9.0:1.0, preferably at least 14.0:1.0, more preferably at least 19.0:1.0.

[0085] In one embodiment of the invention, the binding compound is combined with a flow improving agent (F). The flow improving agent can be chosen from a list of conventional flow improvers preferably one of a naphthalene-based superplasticizer; a lignosulfonate; a protein, such as casein; a naphthalene sulphonate; a melamine-based superplasticizer; a polycarboxylate ether (PCE) or polyacrylate ether (PAE) based superplasticizer, a salt or derivative thereof; and mixtures thereof.

[0086] In one embodiment of the invention, the binding compound (G) is combined with GGBFS (E).

[0087] In one embodiment of the invention, compound (C) is a CaCOs-containing composition according to the EN 197-1 , EN 197-5 or EN 197-6 such as e.g. CEM ll / A- LL or CEM ll / C-M (LL,S). Therefore, if there is enough CaCOs in compound C sufficient, compound (B) is not necessary.

[0088] In one embodiment of the invention, other streams are combined with the binding compound (G) such as an ash, clay, calcined clay, a distinct metallurgical slag, a mine tailing, a quartz filler, bauxite residue or combination thereof.

[0089] In order to facilitate a binder for concrete, grout or mortar, the binding compound (G) is combined with an appropriate amount of water.

[0090] Still preferably, the binding compound can be combined with aggregate to form a concrete, grout or mortar.Experimental Section

[0091] The invention will be now described in more details with reference to the following examples, whose purpose is merely illustrative and not intended to limit the scope of the invention.

[0092] The reported values for particle size distribution (PSD) are based on measurements using the LS 13 320 Particle Size Analyzer (Beckman-Coulter).

[0093] The slump flow is measured by filling a tube with diameter of 2.0 cm and height of 5.0 cm with the mixed mortar composition. The diameter of the mortar after lifting the tube is taken as characteristic value for the flow.Example 1 : composition of the SCM compounds used in further examples

[0094] Table 1 illustrates the composition of different SCM compounds that will be used in the examples below, wherein the components of said SCM compounds areexpressed in weight. As is known by the skilled person, the remainder of a SCM compound (“others” herein) is usually made up of many compounds (typically 10-20) which are typically present in small concentrations.

[0095] X-ray fluorescence measurements to quantify the composition of said SCM’s, were performed by use of a XRF S4 Pioneer (Bruker).Table 1 :

[0096] T able 2 illustrates the mineralogical composition of the three Si-containing slags of Table 1. The mineralogical composition reflects herein the microstructure of the compositions, and was determined herein with X-ray diffraction, making use of a D8 Advance (Bruker). Further quantification was done by use of the Rietveld method.Table 2:

[0097] Table 3 illustrates particle size distribution PSDs to quantify the composition. Table 3:

[0098] In the experiments below, a series of compositions or mixtures for mortars or concrete are presented. The compositions comprise a cementitious binder composition, water and sand for forming said mortar or concrete. The compositions are prepared by mixing the dry components of the mixture, followed by adding under continuous mixing the components in liquid form, the latter relating mainly to the water component. Sand as used herein is CEN Normsand (DIN EN 196-1). The components in the experiments below are expressed in weight.

[0099] After adding all components, mixing is typically done for a period of a few minutes, the period used in the experiments herein is 3 minutes. In a subsequent step, the mixture is casted into molds and allowed to cure at room temperature with a strengthprofile being measured at different times after preparing the mixture (1 day, 2 days, 7 days, and 28 days). Compressive strength of the binder is measured on mortar level using beams produced in line with the EN 196-1 (2016). A higher value for compressed strength is typically regarded as favorable and indicating an improved reactivity of the composition and durability of the final concrete or mortar.Example 2 : Composite binder compositions having a constant OPC content (CE1-CE2, E1-E4)

[0100] Table 4 illustrates cementitious binder compositions CE1-CE2, E1-E4 having varying ratios of (Si-Slag 1: fine CaCCh), while having a fixed content of OPC (CEM I). Said cementitious binder compositions CE1-CE2, E1-E4 are used in a mortar composition with water and sand quantities according to Table 3, following the method described above. CE1 illustrates the case without Si-Slag, whereas CE2 illustrates the case without CaCOs. The development of compressive strength as function of time is illustrated in Figure 1 for each of these compositions, wherein “D” refers to the number of days since the casting of the mold. The amount of Si-Slag in the X-axis of Figure 1 is expressed as wt.% with reference to the total weight of the Si-Slag-based composite binder Si-Slag / CaCCh / OPC. It can be observed that for the 28 days strength, the measured compressive strength is over the compositional range higher for the Si- Slag / CaCOs mixtures than it would be expected from a linear interpolation, in particular a linear interpolation of the OPC / inert CaCCh filler (CE1) and the OPC / Si-Slag (CE2). The expected compressive strength is shown on Figure 1 as the fine interpolating line “Exp”.Table 4:Example 3 : Composite binder compositions having a constant OPC content with GGBFS (CE3-CE7)

[0101] Table 5 illustrates compositions for the same ratios as those mentioned inExample 2, using this time GGBFS as a slag. In other words, the Si-Slag in Example 2is replaced by said GGBFS. The corresponding compressive strengths as function of time are given in Figure 2. Here a rather linear strength increase is noted when gradually increasing the slag concentration of the latent hydraulic ground granulated blast furnace slag GGBFS at the expense of the inert filler CaCOs. Thus, the positive effect of example 2, wherein a higher compressive strength is obtained for the cementitious binder compositions E1-E4 according to the invention, cannot be observed here.Table 5:Example 4 : Composite binder compositions with different Si-Slags (CE8-CE10, E5-E7)

[0102] Table 6 illustrates the influence of the type of Si-Slag used in the composition. As mentioned above, Tables 1 and 2 indicate the chemical composition of said slags, and their degree of amorphous (glassy) content, respectively. Despite this variation, the nature of the observed effect remains the same for the different Si-Slags, as can be seen from the compressive strength data at 28 days in Figure 3. The obtained strength at 28 days is always significant higher for the compositions where fine CaCOs is combined with Si-Slag (E5-E7) in comparison to the case with only Si-Slag and thus in the absence of CaCOs (CE8-CE10).Table 6:Example 5 : Composite binder compositions with varying CEM I content (CE11- CE13, E8-E10)

[0103] Table 7 shows compositions having a varying OPC content, wherein for each value of OPC, the composition may comprise only a Si-Slag or a Si-Slag / CaCOs mixture. The effect on the compressive strength is visible in Figure 4. It is observed that the compositions also comprising the fine limestone always outperform the pure Si-Slag cases for a wide range of cement concentrations, being herein from 30.0% - 70.0%, expressed with reference to the total weight of precursor composition Si- Slag / CaCCh / OPC. Moreover, the relative effect is even larger at high replacement levels (70.0% with 30.0% OPC). The improved compressive strength can in some cases already be noticed after 7 days of curing.Table 7:Example 6 : Composite binder compositions with CaSO4 (E11-E12)

[0104] In Table 8, two compositions are illustrated, with or without the addition of anhydrite (CaSO4) at the expense of the Si-Slag. The corresponding compressive strength values are given in Figure 5. It is observed that the addition of anhydrite (CaSOt) further improves the strength of cured mortar or concrete at 28 days.Table 8:Example 7 : Composite binder compositions - comparison with clay (CE13, E11 )

[0105] In Table 9, two compositions (CE13, E11) are shown, containing either a specific amount of Si-Slag or calcined clay. These compositions are prepared herein with a lower water-to-binder ratio for the purpose of measuring the effect of the choice of SCM on slump flow. It can be observed in Figure 6 that the mechanical performance of both SCM’s is very similar, e.g. the compressive strength values for both compositions after 28 days are very similar. Referring now to Figure 7, the dosage of the superplasticizer (conventional PCE polycarboxylate ether herein) is chosen to have an equal initial slump flow of 200.0 mm, which initial slump flow is measured just after mixing (time = 0 min). It has been observed that the composition with calcined clay requires 2.5 times more superplasticizer compared to the Si-Slag example to reach this initial slump flow. Moreover, when looking at Figure 7, it can be seen that the stability of the slump flow as function time is significantly better for the Si-Slag.Table 9:Example 8 : Composite binder compositions having a constant OPC content with fly ash (CE1 , CE15-CE19)

[0106] Table 10 illustrates compositions for the same ratios as those mentioned in Example 2, using this time pozzolanic fly ash as a SCM. In other words, the Si-Slag in Example 2 is replaced by fly ash. The mechanical performance being the compressive strength development, shown in Figure 8, contrasts with the performance as shown in Figure 1 . Similar to Example 3 and Figure 2, it can be seen that the effect on compressive strength development as observed for the combination of the Si-Slag with fine CaCCh is not obvious when looking at the commonly available secondary SCMs.Table 10: Counter example compositions for varying fly ash-to-fine CaCCh ratio.

[0107] By “’ll LT wt.% of SiC>2 relative to the weight of the Si-Slag” is meant the weight of silicon-containing compounds when expressed in the form of SiC>2 relative to the weight of the Si-Slag. Likewise, by “’W wt.% of AI2O3 relative to the weight of the Si- Slag” is meant the weight of aluminum-containing compounds when expressed in the form of AI2O3 relative to the weight of the Si-Slag. Likewise, by “’WW wt.% of CaO relative to the Si-Slag” is meant the weight of calcium-containing compounds when expressed in the form of CaO relative to the weight of the Si-Slag. Likewise, by “’XX’ wt.% of MnO relative to the Si-Slag” is meant the weight of manganese-containing compounds when expressed in the form of MnO relative to the weight of the Si-Slag. Likewise, by “’YY’ wt.% of Fe2Os relative to the Si-Slag” is meant the weight of iron- containing compounds when expressed in the form of Fe2Os relative to the weight of the Si-Slag. Likewise, by “’ZZ’ wt.% of MgO relative to the Si-Slag” is meant the weight of magnesium-containing compounds when expressed in the form of MgO relative to the weight of the Si-Slag.

[0108] By “the weight ratio SiO2 / (CaO+MgO) in said Si-Slag (A)” is meant the ratio between the weight of silicon-containing compounds when expressed in the form of SiO2 relative to the weight of the Si-Slag and the sum of the weight of calcium-containing compounds when expressed in the form of CaO relative to the weight of the Si-Slag and the weight of magnesium-containing compounds when expressed in the form of MgO relative to the weight of the Si-Slag.

[0109] By “the weight ratio of the AI2O3 content of the Si-Slag (A) to the MnO content of Si-Slag (A)” is meant the ratio between the weight of aluminium-containing compounds when expressed in the form of AI2O3 relative to the weight of the Si-Slag and the weight of manganese-containing compounds when expressed in the form of MnO relative to the weight of the Si-Slag.

[0110] By the expression ”a composition is XX wt. % amorphous” is meant that said composition has a fraction of XX percent of amorphous phase as determined the internal standard method.

[0111] When analyzing XRD patterns, especially those containing both crystalline and amorphous phases (like glass), the internal standard method is employed. The sample which includes both crystalline and amorphous components is mixed with a precisely known amount of a 100.0% crystalline standard material. This is the “internal standard.” Zincite (ZnO) is used as internal standard thanks to its 100.0% crystallinity, symmetric structure and chemically inert character. A content of 5.0 or 10.0 wt.% of zincite is generally added to the specimen. The diffraction pattern obtained will contain peaks from both the sample and the zincite. The refined phase quantities obtained through the Rietveld refinement method will then overestimate the crystalline phases. Knowing the true zincite content added, by difference, the amorphous (glassy) phase can be then evaluated.

[0112] A D50 value (a.k.a. mass-median diameter value (D50)) of a composition is preferably determined with particle size distribution (PSD) of said composition as measured using a LS 13 320 Particle Size Analyzer (Beckman-Coulter).

[0113] Preferred embodiments of the present invention are also defined by the following clauses:1. A cementitious binder composition for a concrete, grout or mortar, said cementitious binder composition comprising or consisting of:(A) at least 5.0 wt.% with reference to the total weight of said binder composition, preferably at least 10.0 wt.% with reference to the total weight of said binder composition, more preferably at least 15.0 wt.% with reference to the total weight of said binder composition, but less than 60.0 wt.% with reference to the total weight of said binder composition, preferably less than 50 wt.% with reference to the total weight of said binder composition of a Si-Slag comprising at least 4.0 wt.% of MnO with reference to the weight of the Si-Slag, at least 15.0 wt.% of CaO with reference to the weight of the Si-Slag and at least 7.5 wt.% of AI2O3 with reference to the weight of the Si-Slag; and(B) optionally, at least 1.0 wt.% with reference to the total weight of said binder composition, preferably at least 2.0 wt.% with reference to the total weight of said binder composition, more preferably at least 4 wt.% with reference to the total weight of said binder composition, even more preferably at least 6.0 wt.% with reference to the total weight of said binder composition, but less than 50.0 wt.%, preferably less than 35.0 wt.% with reference to the total weight of said binder composition of a CaCCh-source(B), wherein said CaCCh-source has a D50 value of at most 30.0 pm, wherein the CaCCh-source has a CaCCh content of at least 20.0 wt.%, preferably at least 40.0 wt.% with reference to the total weight of the CaCOa-source; and(C) at least 5.0 wt.% with reference to the total weight of said binder composition, preferably at least 10.0 wt.% with reference to the total weight of said binder composition, more preferably at least 15 wt.% with reference to the total weight of said binder composition, but less than 90.0 wt.% with reference to the total weight of said binder composition, preferably less than 75.0 wt.% with reference to the total weight of said binder composition of a cement, in particular an Ordinary Portland Cement; and(D) optionally, at least 0.5 wt.% with reference to the total weight of said binder composition but less than 20.0 wt.%, preferably less than 10.0 wt.% with reference to the total weight of said binder composition of a CaSO4- source (D), wherein the CaSO4-source (D) has a CaSO4 content of at least 20.0 wt.%, preferably at least 45.0 wt.% with reference to the total weight of the CaSC>4-source (D); and(E) optionally, at least 2.0 wt.% but less than 50.0 wt.% of a ground granulated blast-furnace slag; and(F) optionally, a flow improving agent; and(G) optionally, at least 2.0 wt.% but less than 50.0 wt.% of a binding compound, preferably said cementitious binder composition having a CaCCh content of at least 1.0 wt.% with reference to the total weight of said binder composition, preferably at least 5.0 wt.% with reference to the total weight of said binder composition, but less than 50.0 wt.% with reference to the total weight of said binder composition, preferably less than 30.0 wt.% with reference to the total weight of said binder composition. The cementitious binder composition for a concrete, grout or mortar according to Clause 1 , wherein said Si-Slag (A) has a D50 value of at most 30.0 pm, preferably at most 10.0 pm.3. The cementitious binder composition for a concrete, grout or mortar according to clause 1 or 2, wherein the Si-Slag (A) and / or the cement (C) comprises CaCCh issued from a different source than the CaCChfrom the CaCCh-source (B).4. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein said Si-Slag is further at least 30.0 wt.%, preferably at least 50.0 wt.%, and more preferably at least 60.0 wt.% amorphous, preferably glassy.5. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the cement (C) is:- the Ordinary Portland cement (OPC), in particular Portland cement (OEM I) according to EN 197-1 (2011), or- a Blended cement, in particular, selected from the group consisting of Portland composite cement (OEM II as EN 197-1 (2011)), blast furnace slag cement (OEM III as EN 197-1 (2011)), pozzolanic cement (OEM IV as EN 197-1 (2011)), slag- pozzolanic cement (OEM V as EN 197-1 (2011)), composite cement (such as OEM ll / C-M (LL,S) and OEM VI as EN 197-5 (2021)), cement with recycle building materials (OEM II and OEM VI as EN 197-6 (2023)), and combinations thereof, or- a combination of the Ordinary Portland cement and the Blended cement.6. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein said Si-Slag (A) has a composition further comprising SiO2 and MgO, wherein the weight ratio SiO2 / (CaO+MgO) in said Si-Slag (A) is at least 0.8, preferably at least 0.9; more preferably said ratio is at least 1.0.7. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the weight ratio of the AI2O3 content of the Si-Slag (A) to the MnO content of Si-Slag (A) is larger than 1 .0.8. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the weight ratio of the Si-Slag (A) to the CaCOa-source (B), meaning (A):(B), is at least 1.0:4.0, preferably at least 1.0:2.0, more preferably at least 1.0: 1.0, even more preferably at least 2.0:1.0.9. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the weight ratio of the Si-Slag (A) and the CaCOa-source (B) to the cement (C), meaning ((A)+(B)):(C)), is at least 1.0:19.0, preferably 1.0:5.0, more preferably 1.0: 1.0.10. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaSC>4-source (D) is different from any one of said compounds (A), (B) or (C).11 . The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein said cementitious binder composition further comprises at least 0.5 wt.% with reference to the total weight of said binder composition but less than 20.0 wt.% preferably less than 10.0 wt.% with reference to the total weight of said binder composition of a CaSC>4-source (D), and wherein the CaSC>4-source (D) has a CaSC>4 content of at least 20.0 wt.%, preferably at least 45.0 wt.% with reference to the total weight of the CaSC>4-source (D), wherein the CaSC>4-source (D) and comprises one or more of the following:- CaSC>4 (anhydrite),- alfa-CaSO4.3 H2O (alfa hemi-hydrate),- beta-CaSO4.3 H2O (beta hemi-hydrate),- CaSC>4.2H2O (gypsum),- CaSC>4.2H2O (phosphogypsum),- SOa-scrubber gypsum.12. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the flow improving agent (F) is selected from the list consisting of naphthalene-based superplasticizer; a lignosulfonate; a protein, such as casein; a naphthalene sulphonate; a melamine- based superplasticizer; a polycarboxylate ether (PCE) or polyacrylate ether (PAE) based superplasticizer, a salt or derivative thereof; and mixtures thereof.13. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the binding compound (G) is selected from the list consisting of an ash, a clay, a calcined clay, a distinct metallurgical slag, a mine tailing, a quartz filler, a bauxite residue, and mixtures thereof.14. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaCCh-source (B) is different from the Si-Slag (A) and / or the cement (C), or wherein the Si-Slag (A) being different from the cement (C).15. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaCCh-source (B) is different from the Si-Slag (A).16. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaCCh-source (B) is different from the cement (C).17. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Cement (C) is different from the cement Si-Slag (A).18. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at least 17.0 wt.%, preferably at least 20.0 wt.%, more preferably at least 21.0 wt.%, even more preferably at least 22.0 wt.% of CaO, with respect to the total weight of the Si- Slag (A).19. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at most 40.0 wt.%, preferably at most 38.0 wt.%, more preferably at most 35.0 wt.%, even more preferably at most 33.0 wt.%, still more preferably at most 30.0 wt.% of CaO, with respect to the total weight of the Si-Slag (A).20. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at least 2.0 wt.%, preferably at least 3.0 wt.%, more preferably at least 3.5 wt.%, even more preferably at least 4.0 wt.%, still more preferably at least 4.5 wt.% of MgO, with respect to the total weight of the Si-Slag (A).21 . The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at most 13.0 wt.%, preferably at most 12.0 wt.%, more preferably at most 11.0 wt.%, even morepreferably at most 10.5 wt.%, still more preferably at most 10.0 wt.%, most preferably at most 9.5 wt.% of MgO, with respect to the total weight of the Si-Slag (A).22. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at least 9.0 wt.%, preferably at least 11.0 wt.%, more preferably at least 12.0 wt.%, still more preferably at least 13.0 wt.% of AI2O3, with respect to the total weight of the Si- Slag (A).23. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at most 30.0 wt.%, preferably at most 28.0 wt.%, more preferably at most 25.0 wt.%, even more preferably at most 23.0 wt.%, still more preferably at most 20.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag (A).24. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at least 20.0 wt.%, preferably at least 22.0 wt.%, more preferably at least 25.0 wt.%, even more preferably at least 27.0 wt.%, still more preferably at least 30.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag (A).25. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has most 50.0 wt.%, preferably at most 48.0 wt.%, more preferably at most 45.0 wt.%, even more preferably at most 43.0 wt.%, still more preferably at most 40.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag (A).26. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at least 0.1 wt.%, preferably at least 0.2 wt.%, more preferably at least 0.3 wt.% of Fe2Os, with respect to the total weight of the Si-Slag (A).27. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at most 10.0 wt.%, preferably at most 7.0 wt.%, more preferably at most 5.0 wt.%, even morepreferably at most 2.0 wt.%, still more preferably at most 1 .0 wt.% of Fe20a, with respect to the total weight of the Si-Slag (A), The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at least 6.0 wt.%, preferably at least 7.0 wt.%, more preferably at least 8.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag (A). The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has at most 22.0 wt.%, preferably at most 20.0 wt.%, more preferably at most 18.0 wt.%, even more preferably at most 16.0 wt.%, still more preferably at most 14.0 wt.%, most preferably at most 12.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag (A). The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the Si-Slag (A) has a D50 value smaller than 25.0 pm, preferably smaller than 20.0 pm, more preferably smaller than 15.0 pm. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaCCh-source (B) has at least 20.0 wt.% of carbonates, preferably at least 40.0 wt.% of carbonates, more preferably at least 60.0 wt.% of carbonates. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaCCh-source (B) has a CaCCh content of at least 60.0 wt.% of CaCCh with respect to the total weight of the CaCCh-source (B). The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaCCh-source (B) has a D50 value smaller than 25.0 pm, preferably smaller than 20.0 pm, more preferably smaller than 15.0 pm, even more preferably smaller than 10.0 pm.34. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding clauses, wherein the CaCCh-source (B) has a Dmax value smaller than 63.0 pm, preferably smaller than 50.0 pm, more preferably smaller than 45.0 pm.35. A mortar, concrete or grout composition comprising the cementitious binder composition according to any one of Clauses 1-34, and at least one of aggregate, water, sand and gravel.36. A process to obtain a cementitious binder composition according to any one of clauses 1-34, said process comprising the steps of:- providing the Si-Slag (A);- optionally providing the CaCCh-source (B);- providing the cement(C);- optionally providing one or more compounds selected from the group comprising: the CaSC>4-source (D), the ground granulated blastfurnace slag (E), flow improving agent (F) and the binding compound (G);- mixing the Si-Slag (A), optionally the CaCCh-source (B) and the cement (C) and optionally water and optionally the one or more compounds selected from the group comprising: the CaSC>4-source (D), the ground granulated blast-furnace slag (E), flow improving agent (F) and the binding compound (G).37. A process for the manufacturing of a premix for a cementitious binder composition according to any one of clauses 1-34, said process comprising the steps of:- providing the Si-Slag (A);- providing the CaCOs-source (B);- mixing the Si-Slag (A), with the CaCOs-source (B) to form said premix.38. A process for the manufacturing of a cementitious binder composition according to any one of clauses 1-34, said process comprises the step of- optionally providing the cement (C);- optionally providing the premix obtained with the process of clause 37;- optionally providing one or more compounds selected from the group comprising: the CaSC>4-source (D), the ground granulated blastfurnace slag (E), flow improving agent (F) and the binding compound (G);- mixing said premix obtained with the process of clause 37 with the cement (C) and optionally the one or more compounds selected from the group comprising: the CaSC>4-source (D), the ground granulated blast-furnace slag (E), flow improving agent (F) and the binding compound (G), to form the cementitious binder composition. . A cementitious binder precursor composition for a cementitious binder composition for a concrete, grout or mortar, said cementitious binder precursor composition comprising or consisting of:(a) at least 7.0 wt.% with reference to the total weight of said precursor composition but less than 85.0 wt.% with reference to the total weight of said precursor composition, preferably less than 70.0 wt.% with reference to the total weight of said precursor composition of a Si-Slag, comprising at least 4.0 wt.% of MnO with reference to the weight of the Si-Slag, at least 15.0 wt.% of CaO with reference to the weight of the Si-Slag and at least 7.5 wt.% of AI2O3 with reference to the weight of the Si-Slag, preferably said Si-Slag being further at least 30.0 wt.% amorphous, preferably glassy;(B) at least 2.0 wt.% with reference to the total weight of said precursor composition but less than 70.0 wt.% with reference to the total weight of said precursor composition of a CaCOs-source (B), and wherein said CaCOs-source (B) has a D50 value of at most 30.0 pm, wherein the CaCOs-source (B) has a CaCOs content of at least 20.0 wt.%, preferably at least 40.0 wt.% with reference to the total weight of the CaCOs-source (B), preferably said cementitious binder precursor composition having a CaCOs content of at least 1.0 wt.% with reference to the total weight of said precursor composition but less than 35.0 wt.% with reference to the total weight of said precursor composition, preferably less than 20 wt.% with reference to the total weight of said precursor composition.The cementitious binder precursor composition according to clause 39, wherein said Si-Slag (A) has a D50 value of at most 30.0 pm, preferably at most 10.0 pm. The cementitious binder precursor composition according to any one of clauses 39 to 40, wherein said Si-Slag (A) has a composition further comprising SiC>2 and MgO, wherein the weight ratio SiC>2 / (CaO+MgO) in said Si-Slag (A) is at least 0.8, preferably at least 0.9; more preferably said ratio is at least 1.0. The cementitious binder precursor composition according to any one of clauses 39 to 41 , wherein the weight ratio of the AI2O3 content of the Si-Slag (A) to the MnO content of Si-Slag (A) is larger than 1.0. The cementitious binder precursor composition according to any one of clauses 39 to 42, wherein the weight ratio of the Si-Slag (A) to the CaCCh-source (B), meaning (A):(B), is at least 1.0:4.0, preferably at least 1.0:2.0, more preferably at least 1.0:1.0, even more preferably at least 2.0:1.0. The cementitious binder precursor composition according to any one of clauses 39 to 43, wherein the Si-slag (A) comprises CaCCh issued from a different source than the CaCCh from the CaCCh-source (B). The cementitious binder precursor composition according to any one of clauses 39 to 44, further comprises at least 1.0 wt.% with reference to the total weight of said precursor composition but less than 30.0 wt.%, preferably less than 15.0 wt.% with reference to the total weight of said precursor composition of a CaSC>4- source (D), and wherein the CaSC>4-source (D) has a CaSC>4 content of at least 20.0 wt.%, preferably at least 45.0 wt.% with reference to the total weight of the CaSC>4-source (D), and wherein the CaSC>4-source (D) comprises one or more of the following:- CaSC>4 (anhydrite),- alfa-CaSO4.3 H2O (alfa hemi-hydrate),- beta-CaSO4.3 H2O (beta hemi-hydrate),- CaSC>4.2H2O (gypsum),- CaSC>4.2H2O (phosphogypsum),- SCh-scrubber gypsum.46. The cementitious binder precursor composition according to any one of clauses 39 to 45, wherein the Si-Slag (A) and / or the CaCCh-source (B) comprises CaSC>4 from a different source than the CaSC>4 from the CaSC>4-source (D).47. The cementitious binder precursor composition according to any one of clauses 39 to 46, wherein the cementitious binder precursor composition further comprises at least 3.0 wt.% with reference to the total weight of said precursor composition but less than 65.0 wt.% with reference to the total weight of said precursor composition of a ground granulated blast-furnace slag (GGBFS).48. The cementitious binder precursor composition according to any one of clauses 39 to 47, wherein the Si-Slag (A) has at least 17.0 wt.%, preferably at least 20.0 wt.%, more preferably at least 21.0 wt.%, even more preferably at least 22.0 wt.% of CaO, with respect to the total weight of the Si-Slag (A).49. The cementitious binder precursor composition according to any one of clauses 39 to 48, wherein the Si-Slag (A) has at most 40.0 wt.%, preferably at most 38.0 wt.%, more preferably at most 35.0 wt.%, even more preferably at most 33.0 wt.%, still more preferably at most 30.0 wt.% of CaO, with respect to the total weight of the Si-Slag (A).50. The cementitious binder precursor composition according to any one of clauses 39 to 49, wherein the Si-Slag (A) has at least 2.0 wt.%, preferably at least 3.0 wt.%, more preferably at least 3.5 wt.%, even more preferably at least 4.0 wt.%, still more preferably at least 4.5 wt.% of MgO, with respect to the total weight of the Si-Slag (A).51. The cementitious binder precursor composition according to any one of clauses 39 to 50, wherein the Si-Slag (A) has at most 13.0 wt.%, preferably at most 12.0 wt.%, more preferably at most 11.0 wt.%, even more preferably at most 10.5 wt.%, still more preferably at most 10.0 wt.%, most preferably at most 9.5 wt.% of MgO, with respect to the total weight of the Si-Slag (A).52. The cementitious binder precursor composition according to any one of clauses39 to 51 , wherein the Si-Slag (A) has at least 9.0 wt.%, preferably at least 11.0wt.%, more preferably at least 12.0 wt.%, still more preferably at least 13.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag (A).53. The cementitious binder precursor composition according to any one of clauses 39 to 52, wherein the Si-Slag (A) has at most 30.0 wt.%, preferably at most 28.0 wt.%, more preferably at most 25.0 wt.%, even more preferably at most 23.0 wt.%, still more preferably at most 20.0 wt.% of AI2O3, with respect to the total weight of the Si-Slag (A).54. The cementitious binder precursor composition according to any one of clauses 39 to 53, wherein the Si-Slag (A) has at least 20.0 wt.%, preferably at least 22.0 wt.%, more preferably at least 25.0 wt.%, even more preferably at least 27.0 wt.%, still more preferably at least 30.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag (A).55. The cementitious binder precursor composition according to any one of clauses 39 to 54, wherein the Si-Slag (A) has most 50.0 wt.%, preferably at most 48.0 wt.%, more preferably at most 45.0 wt.%, even more preferably at most 43.0 wt.%, still more preferably at most 40.0 wt.% of SiC>2, with respect to the total weight of the Si-Slag (A).56. The cementitious binder precursor composition according to any one of clauses 39 to 55, wherein the Si-Slag (A) has at least 0.1 wt.%, preferably at least 0.2 wt.%, more preferably at least 0.3 wt.% of Fe2Os, with respect to the total weight of the Si-Slag (A).57. The cementitious binder precursor composition according to any one of clauses 39 to 56, wherein the Si-Slag (A) has at most 10.0 wt.%, preferably at most 7.0 wt.%, more preferably at most 5.0 wt.%, even more preferably at most 2.0 wt.%, still more preferably at most 1.0 wt.% of Fe2Os, with respect to the total weight of the Si-Slag (A).58. The cementitious binder precursor composition according to any one of clauses 39 to 57, wherein the Si-Slag (A) has at least 6.0 wt.%, preferably at least 7.0 wt.%, more preferably at least 8.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag (A).59. The cementitious binder precursor composition according to any one of clauses 39 to 58, wherein the Si-Slag (A) has at most 22.0 wt.%, preferably at most 20.0 wt.%, more preferably at most 18.0 wt.%, even more preferably at most 16.0 wt.%, still more preferably at most 14.0 wt.%, most preferably at most 12.0 wt.% of manganese oxide, expressed as MnO, with respect to the total weight of the Si-Slag (A).60. The cementitious binder precursor composition according to any one of clauses 39 to 59, wherein the Si-Slag (A) has a D50 value smaller than 25.0 pm, preferably smaller than 20.0 pm, more preferably smaller than 15.0 pm.61. The cementitious binder precursor composition according to any one of clauses 39 to 60, wherein the CaCCh-source (B) has at least 20.0 wt.% of carbonates, preferably at least 40.0 wt.% of carbonates, more preferably at least 60.0 wt.% of carbonates.62. The cementitious binder precursor composition according to any one of clauses 39 to 61 , wherein the CaCCh-source (B) has a CaCCh content of at least 60.0 wt.% of CaCCh with respect to the total weight of the CaCCh-source (B).63. The cementitious binder precursor composition according to any one of clauses 39 to 62, wherein the CaCCh-source (B) has a D50 value smaller than 25.0 pm, preferably smaller than 20.0 pm, more preferably smaller than 15.0 pm, even more preferably smaller than 10.0 pm.64. The cementitious binder precursor composition according to any one of clauses 39 to 63, wherein the CaCCh-source (B) has a Dmax value smaller than 63.0 pm, preferably smaller than 50.0 pm, more preferably smaller than 45.0 pm.65. The cementitious binder precursor composition according to any one of clauses 39 to 64, wherein the CaCCh-source (B) is different from the Si-Slag (A).66. A process for the manufacturing of a cementitious binder precursor composition for a cementitious binder composition for a concrete, grout or mortar, according to any one of the clauses 39 to 65, said process comprising the steps of:- providing the Si-Slag (A);- providing the CaCCh-source (B);- Mixing the Si-Slag (A), with the CaCCh-source (B) to form said cementitious binder precursor composition.

Claims

Claims1. A cementitious binder composition for a concrete, grout or mortar, said cementitious binder composition comprising:(A) at least 5.0 wt.% with reference to the total weight of said binder composition, preferably at least 10.0 wt.% with reference to the total weight of said binder composition, more preferably at least 15.0 wt.% with reference to the total weight of said binder composition, but less than 60.0 wt.% with reference to the total weight of said binder composition, preferably less than 50.0 wt.% with reference to the total weight of said binder composition of a Si-Slag, wherein the Si-Slag has at least 4.0 wt.% of MnO with reference to the weight of the Si-Slag, at least 15.0 wt.% of CaO with reference to the weight of the Si-Slag, and at least 7.5 wt.% of AI2O3 with reference to the weight of the Si-Slag; and(B) optionally, at least 1.0 wt.% with reference to the total weight of said binder composition, preferably at least 2.0 wt.% with reference to the total weight of said binder composition, more preferably at least 4 wt.% with reference to the total weight of said binder composition, even more preferably at least 6.0 wt.% with reference to the total weight of said binder composition, but less than 50.0 wt.% with reference to the total weight of said binder composition, preferably less than 35.0 wt.% of a CaCCh- source, wherein the CaCCh-source has a D50 value of at most 30.0 pm, and wherein the CaCCh-source has a CaCCh content of at least 20.0 wt.%, preferably at least 40.0 wt.% with reference to the total weight of the CaCOa-source; and(C) at least 5.0 wt.% with reference to the total weight of said binder composition, preferably at least 10.0 wt.% with reference to the total weight of said binder composition, more preferably at least 15 wt.% with reference to the total weight of said binder composition, but less than 90.0 wt.% with reference to the total weight of said binder composition, preferably less than 75 wt.% with reference to the total weight of said binder composition of a cement. wherein said cementitious binder composition has a CaCCh content of at least 1 .0 wt.% with reference to the total weight of said binder composition, preferably at least 5.0 wt.% with reference to the total weight of said binder composition but, less than 50.0 wt.% with reference to the total weight of said binder composition,preferably less than 30.0 wt.% with reference to the total weight of said binder composition.

2. The cementitious binder composition for a concrete, grout or mortar according to claim 1 , wherein the Si-Slag (A) has a D50 value of at most 30.0 pm, preferably at most 10.0 pm.

3. The cementitious binder composition for a concrete, grout or mortar according any one of the preceding claims, wherein the cement is:- an Ordinary Portland cement (OPC), in particular Portland cement (OEM I) according to EN 197-1 (2011), or- a Blended cement, in particular, selected from the group consisting of Portland composite cement (OEM II as EN 197-1 (2011)), blast furnace slag cement (OEM III as EN 197-1 (2011)), pozzolan cement (OEM IV as EN 197-1 (2011)), slag- pozzolanic cement (OEM V as EN 197-1 (2011)), composite cement (such as OEM ll / C-M (LL,S) and OEM VI as EN 197-5 (2021)), cement with recycle building materials (OEM II and OEM VI as EN 197-6 (2023)), and combinations thereof, or- a combination of the Ordinary Portland cement (OPC) and the Blended cement.

4. The cementitious binder composition according to any one of the preceding claims, wherein the Si-Slag (A) has a composition further comprising SiO2 and MgO, wherein the weight ratio SiO2 / (CaO+MgO) in said Si-Slag (A) is at least 0.8, preferably at least 0.9; more preferably said ratio is at least 1.0.

5. The cementitious binder composition for a concrete, grout or mortar according to any one of the preceding claims, wherein the weight ratio of the AI2O3 content of the Si-Slag (A) to the MnO content of the Si-Slag (A) is larger than 1.0.

6. The cementitious binder composition according to any one of the preceding claims, wherein the weight ratio of the Si-Slag (A) to the CaCCh-source (B), meaning (A):(B), is at least 1.0:4.0, preferably at least 1.0:2.0, more preferably at least 1.0:1.0, even more preferably at least 2.0:1.0.

7. The cementitious binder composition according to any one of the preceding claims, wherein the weight ratio of the Si-Slag (A) and the CaCCh-source (B) tothe cement (C), meaning ((A)+(B)):(C)), is at least 1.0:19.0, preferably at least 1 .0:5.0, more preferably at least 1 .0: 1.0.

8. The cementitious binder composition according to any one of the preceding claims, wherein said Si-Slag (A) is at least 30.0 wt.%, preferably at least 50%, and more preferably at least 60 wt.% amorphous.

9. The cementitious binder composition according to any one of the preceding claims, wherein said cementitious binder composition further comprises at least 0.5 wt.% with reference to the total weight of said binder composition but less than 20.0 wt.% preferably less than 10.0 wt.% with reference to the total weight of said binder composition of a CaSC>4-source (D), and wherein the CaSC>4- source (D) has a CaSC>4 content of at least 20.0 wt.%, preferably at least 45.0 wt.% with reference to the total weight of the CaSC>4-source (D), wherein the CaSC>4-source (D) comprises one or more of the following:- CaSC>4 (anhydrite),- alfa-CaSO4.3 H2O (alfa hemi-hydrate),- beta-CaSO4.3 H2O (beta hemi-hydrate),- CaSC>4.2H2O (gypsum),- CaSC>4.2H2O (phosphogypsum),- SOa-scrubber gypsum.

10. The cementitious binder composition according to any one of the preceding claims, wherein said cementitious binder composition further comprises at least 2.0 wt.% with reference to the total weight of said binder composition but less than 50 wt.% with reference to the total weight of said binder composition of a ground granulated blast-furnace slag (GGBFS) (E).

11. The cementitious binder composition according to any one of the preceding claims, wherein said cementitious binder composition further comprises a flow improving agent (F), which agent is preferably selected from the list consisting of a naphthalene-based superplasticizer; a lignosulfonate; a protein, such as casein; a naphthalene sulphonate; a melamine-based superplasticizer; a polycarboxylate ether (PCE) or polyacrylate ether (PAE) based superplasticizer, a salt or derivative thereof; and mixtures thereof.

12. The cementitious binder composition according to any one of the preceding claims, wherein said cementitious binder composition further comprises at least 2.0 wt.% with reference to the total weight of said binder composition but less than 50.0 wt.% with reference to the total weight of said binder composition of a binding compound (G), said binding compound being selected from the list consisting of an ash, a clay, a calcined clay, a distinct metallurgical slag, a mine tailing, a quartz filler, bauxite residue, and mixtures thereof.

13. The cementitious binder composition according to any one of the preceding claims, wherein the CaCCh-source (B) is different from the Si-Slag (A) and / or the cement (C), preferably the Si-Slag (A) being different from the cement (C).

14. A mortar, concrete or grout composition comprising the cementitious binder composition according to any one Claims 1-13, and at least one of aggregate, water, sand and gravel.

15. A process for the manufacturing of a premix for a cementitious binder composition according to any one of claims 1-13 comprising the steps of:- providing the Si-Slag (A);- providing the CaCCh-source (B);- mixing the Si-Slag (A), with the CaCCh-source (B) to form a premix.

16. A process for the manufacturing of a cementitious binder composition according to any one of claims 1-13, said process comprises the step of mixing the premix obtained with the process of claim 15 with the cement (C), to form said cementitious binder composition.

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