[go: up one dir, main page]

WO2025133379A1 - Procédé de fabrication d'un produit en fibrociment - Google Patents

Procédé de fabrication d'un produit en fibrociment Download PDF

Info

Publication number
WO2025133379A1
WO2025133379A1 PCT/EP2024/088303 EP2024088303W WO2025133379A1 WO 2025133379 A1 WO2025133379 A1 WO 2025133379A1 EP 2024088303 W EP2024088303 W EP 2024088303W WO 2025133379 A1 WO2025133379 A1 WO 2025133379A1
Authority
WO
WIPO (PCT)
Prior art keywords
cement
fiber cement
weight
amount
fiber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/EP2024/088303
Other languages
English (en)
Inventor
Katrijn Gijbels
Luc Van Der Heyden
Joyce MAREELS
Stefan CHAVES FIGUEIREDO
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Etex Services NV
Original Assignee
Etex Services NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Etex Services NV filed Critical Etex Services NV
Publication of WO2025133379A1 publication Critical patent/WO2025133379A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
    • C04B28/04—Portland cements
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
    • C04B20/02—Treatment
    • C04B20/023—Chemical treatment
    • C04B20/0232—Chemical treatment with carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00034—Physico-chemical characteristics of the mixtures
    • C04B2111/00129—Extrudable mixtures

Definitions

  • the invention further relates to the resulting fiber cement product and a fiber cement paste for use in the method.
  • Extrusion has been known since long as a production method for fiber cement products. Traditionally, it has been used for manufacturing of tubes and the like. More recently, extrusion has also been mentioned as a manufacturing method for fiber cement sheets or beams.
  • extrusion of fiber cement materials is not easy. For a material to be extrudable, it must be soft enough to flow through the extrusion die. Furthermore, the pressure required for extrusion must be reasonably low, so as to control manufacturing costs. Phase migration must be avoided and the material should be shape stable. Additionally, the resulting fiber cement sheet should meet performance requirements for exterior building materials, such as freeze-thaw resistance, dimensional stability.
  • fiber cement paste comprise cement, fibers and water.
  • a cellulose ether is used as a rheology modifier, and silica fume may also be added.
  • Kuder and Shah, Construction Materials 24 (2010), 181-186 used a composition of 33% class F fly ash, 12% silica fume, 14% cement, 39% water and 1% water-reducing admixture (i.e. rheology modifier). They do not mention the use of fibers.
  • WO2013/082524 mentions use of a paste comprising cement, fibers in the form of pulp and of reinforcement fibers and one or more air entrainment agents in addition to water.
  • the paste preferably comprises 35-70% cement, 0-15% reinforcing fibers, 10-70% silicious aggregates, 0-0.1% air entrainment agent and 0.6-1% viscosity enhancement agent.
  • High-melting polymer-based synthetic fibers such as polypropylene fibers are preferred due to their higher viscoelastic performance than wood-based fiber.
  • the resulting green product is hardened by autoclave-curing.
  • the specified application is for sidings, which are plank-shaped panels for use in fagade coverings.
  • US5,891,374 mentions extrusion of fiber cement paste with a variety of fibers, including polyvinyl alcohol (PVA), carbon, microsteel, cellulose and polypropylene (PP).
  • PVA polyvinyl alcohol
  • PP polypropylene
  • the length of the PVA and carbon fibers was 6 mm, that of PP 19 mm, and that of cellulose 2.55 mm.
  • the diameter was from 15 pm for PVA fibers to 30 pm for PP fibers and 30-120 pm for cellulose fibers. It is shown in comparative tests relative to casting, that the extrusion process increases the strength of the resulting product.
  • the fibers therein show a high degree of preferential alignment in the extrusion direction.
  • the first object is achieved in a method of manufacturing a fiber cement product, comprising the steps of: (1) Providing a fiber cement paste comprising cement, fibers and water; (2) extruding the fiber cement paste to form a green article, and (3) curing the green article to obtain the fiber cement product, wherein the fiber cement paste comprises a cementitious material obtainable by carbonating a cured cementitious material.
  • the second object is achieved in an extrudable fiber cement composition
  • comprising fibers, cement and water further comprising a cementitious material obtainable by carbonating a cured cementitious material.
  • the further object is achieved in a fiber cement product obtainable with the method of the invention.
  • carbonated cementitious material is added into the fiber cement paste.
  • the terms 'extrudable fiber cement composition' and 'fiber cement paste' are herein used as having identical meaning .
  • the term 'paste' indicates a distinction to aqueous slurries used in Hatschek processing, as the amount of added water in the extrudable fiber cement composition is much less, such as at most 50% by weight based on the total dry weight of the composition, and preferably at most 30% by weight, based on the total dry weight of the composition.
  • Such carbonated cementitious material is cured, as it typically originates from recycling of cement products, such as recycled fiber cement products or concrete, such as recycled concrete paste (RCP).
  • the material is typically in the form of powder or fines, as this improves both uniformity of distribution in the extrudable fiber cement composition, and moreover increases the surface area and therewith enhances the carbonation process.
  • the added material obtainable by carbonating of cured cementitious material is also referred to as carbonated cement fines, or more generally carbonated cement powder.
  • this carbonated cement powder may be an autoclave- cured powder and an air-cured powder.
  • the carbonated cement powder itself may be part of a fiber cement composition for air-curing or for autoclave-curing.
  • the carbonated cement powder may originate from fiber cement waste or from other sources, such as from the recycled concrete powder (RCP) in concrete waste.
  • the invention is based on the insight that the carbonated cement powder is by itself a powder, such obtained by sieving through a sieve in the range of 75-200 pm, for instance a sieve of 100 pm or 150 pm.
  • a mean average particle size (d50 as defined by laser diffraction) in the range of 10-40 pm is preferred, such as between 15 and 25 pm.
  • the cured powder is thus equally fine or less fine than fresh cement. It can be considered as a fine aggregate, and hence may provide a counterforce against too much fiber alignment as a consequence of the extrusion process.
  • carbonated cement powder is a pozzolanic material that is capable of reacting quickly with calcium hydroxide.
  • Such calcium hydroxide is liberated from cement during hydration in water, and then deemed available in aqueous form. This process happens also in the course of the extrusion processing of the cement paste and directly thereafter. Therefore, the carbonated cement powder can react with the liberated calcium hydroxide early in the manufacturing process and contribute to shape stability; the hydration products resulting from the reaction between calcium hydroxide and carbonated material will again be a solid and thus may help to replace the dissolved and thus removed calcium hydroxide.
  • the use of carbonated material is shown to provide increased flexural and compressive strength, particularly in direct comparison to use of a corresponding amount of noncarbonated recycled cement material.
  • the use of carbonated cement powder may further reduce the water demand of the fiber cement paste. Water demand is to be understood as an amount of water necessary to obtain a predefined rheology of the fiber cement paste, as has been identified appropriate for processing the paste on the used extruder apparatus and in accordance with specified process settings.
  • the amount of carbonated cement powder in the extrudable fiber cement composition is in the range of 5 to 40% by weight based on the dry weight of the extrudable fiber cement composition, more preferably 10-30%.
  • approximately 10-40% by weight of cement and/or silica-based materials such as quartz and fly ash could be substituted by carbonated cement powder. It was found in preliminary experiments that the use of carbonated cement powder provides an increase in both compressive strength and flexural strength when comparing the use of carbonated cement powder and the use of non-carbonated cement powder that was otherwise corresponding.
  • the carbonated cement powder has a particle size distribution such that the d90 is less than 150 pm, preferably less than 100 pm, and wherein the d50 is within the range of 10-60 pm, preferably 10-40 pm, more preferably 15-30 pm.
  • a particle size distribution may be obtained by recycling cement waste and processing it through comminuting and sieving.
  • a preferred way of comminution uses a roller mill, and especially a vertical roller mill with an integrated classifier.
  • the carbonated cement powder may be obtained from material that has been cured in any feasible way, such as air-curing, autoclave-curing or even carbonation (CO2)-curing.
  • the type of curing has an impact on the mineralogy of the cement material, and hence is distinct for air-cured material as opposed to autoclave-cured materials.
  • Such material turns out to have stronger pozzolanic properties and an improved composition than cementitious powders obtained from carbonation of either recycled concrete paste or other air-cured cement material, such as air-cured fiber cement material.
  • the improvement particularly resides in a comparatively high content of the alumina-silica phase (also referred to as alumina-silica gel) in the carbonated powder and therein a comparatively high concentration of silica.
  • autoclave-curing is a method of steam curing of a material comprising both a source of calcium oxide and a source of silicon oxide, wherein the product is put to steam at a temperature above 100°C and a pressure well above atmospheric pressure, such as at least 5 bar, for a predetermined period of time.
  • calcium oxide and silica provided as raw materials will react to form calcium silicates, that might be present in amorphous form, typically referred to as a calcium silicate hydrate (CSH) gel, or in the form of crystalline calcium silicate.
  • CSH calcium silicate hydrate
  • Autoclave-curing particularly results in crystalline material, whereas air-curing rather results in the amorphous gel material.
  • An important crystalline phase is tobermorite, which is understood to contribute to the strength of the resulting material.
  • Other crystalline phases of calcium silicate include xonotlite and wollastonite.
  • the mixing ratio A/B between autoclave-cured material (A) and air-cured material (B) is preferably chosen in the range of 0.25 to 100 on a weight-basis; a mixing ratio of at least 1 is deemed preferable, and a mixing ratio of at least 3 (25% air-cured material), at least 6 or at least 9 (10% air-cured material) is even more preferable.
  • the mixing ratio may be in the ratio of 6 to 19 (5 to 17% aircured material) and is intended to arrive at a predefined composition notwithstanding variations in supply of waste material.
  • a crystalline calcium silicate material typically has an initial density below 1.0 kg/dm3, whereas a waste material for high-density fiber cement products may have a density of at least 1.5 kg/dm3, or even more. Mixing sources may thus be useful.
  • autoclave-cured calcium silicate waste material is mixed with autoclave- cured fiber cement waste material, preferably fiber cement waste material from so-called mediumdensity or high-density products.
  • Such calcium silicate material is known by itself and is for instance sold by Promat® under the tradename Promaxon® and in the form of fire-resistant plates.
  • the carbonated cement powder is obtainable from carbonating recycled fiber cement waste.
  • the carbonated cement powder may further comprises fibers, such as synthetic fibers, cellulose fibers and optionally inorganic fibers.
  • Fiber cement is a very pure material, as it does neither include aggregate nor a significant level of organic additives. This is beneficial for its reuse.
  • the amount and type of fibers depends on the type of fiber cement, with autoclave-cured fiber cement material comprising more fibers than air-cured fiber cement material. However, the amount of fibers may be reduced by treatment of fiber cement waste material.
  • a preferred way of manufacturing fiber cement products is by means of the Hatschek or the flow-on process, with the Hatschek process being most preferred.
  • the carbonated cement powder obtainable from carbonating recycled fiber cement waste has the same particle size distribution and moreover has a fiber content of at most 6% by weight based on the carbonated cement powder.
  • the fiber content is at most 5% by weight.
  • a cement powder with such a distribution is obtainable by using in sequence a vertical roller mill with an integrated air classifier and a sieve, especially a sieve with a sieve size of 150 pm or 100pm. More preferably, the vertical roller mill comprises a chamber that is heated by means of flow of heating gas, such as air. The heating up of the chamber and the cement powder therein is deemed beneficial to obtain a full separation between cement and fibers. Moreover, drying is relevant to ensure efficient and effective sieving.
  • Passing the air classifier which operates as a centrifuge, may aid in obtaining said separation of the fibers from cementitious particles.
  • Investigations of the resulting cementitious powder by means of optical analysis have shown that most fibers, if not all fibers, are liberated from the cementitious particles. Most may herein be understood as at least 90% by weight based on the total weight of the fibers. Preferably, this is even at least 95% by weight.
  • the milling chamber was heated to a temperature in the range of 70-90 °C. This principle is further elucidated in the nonprepublished application PCT/EP2023/067870 in the name of the applicant of the present application, which is included herein by reference. Based on this liberation a major portion of the fibers may be removed from the waste material, for instance at least 30% by weight, or even at least 40% by weight.
  • the carbonated cement powder comprises fibers with an arithmetic average length in the range of 0.25 to 0.50 mm, preferably in the range of 0.30 mm to 0.45 mm.
  • Such short fibers are especially organic fibers, such as cellulose fibers and/or synthetic fibers.
  • the short fibers are shorter than conventional organic fibers used in fiber cement compositions. Compared to conventional organic fibers, such short fibers will have positive impact on flowability, but the contribution to strength may be reduced.
  • the arithmetic average fibre length can be distinguished from the length weighted average fiber length, as often used in the wood pulp industry. It can be is herein obtained by optical analysis. The ratio of the two different fiber length is the polydispersity, which is a measure of the broadness of the length distribution.
  • the recycled cured cement powder is wetted prior and/or during the carbonation treatment.
  • Wetting preferably occurs to a mass ratio of water over binder (w/b) of at least 0.20, and preferably at most 0.4, and more preferably in the range of 0.25-0.35, when measured at the start of the carbonation step.
  • the presence of sufficient water is understood to contribute to effective carbonation, i.e. the formation of COs 2- from CO2 and H2O via H2CO3 and/or HCOs", as known per se.
  • the carbonation step may itself be carried out in various ways.
  • the carbonation is performed in a plurality of cycles, wherein prior to each cycle the cementitious powder is de-agglomerized and wetted.
  • a specific reactor may be provided, wherein the cementitious powder is wetted and/or de-agglomerized during the carbonation, for instance by means of a mixing device.
  • the extrudable fiber cement composition comprises cement and fibers, in addition to the carbonated cement powder.
  • the total amount of cement-type ingredients is preferably at least 40% by weight, based on dry weight of the total composition and more preferably at least 50% by weight, or even at least 60% by weight.
  • the cement-type ingredients in an extrudable air-curable composition are present in an amount in the range of 40-800% by weight, or even 50-70% by weight.
  • the percentage of carbonated cement powder compared to said total amount of cement and carbonated cement powder is preferably in the range of 15-45%, such as between 20 and 40% by weight.
  • cement-type ingredients include any cement-containing material in cured or uncured form, and therewith comprise recycled cement material, typically present as fines, fresh cement material, such as Portland cement, and recovered materials, especially materials recovered during industrial manufacture of other materials than cement, such as slag.
  • An extrudable, air-curable fiber cement composition comprising slag as a cement-type ingredient is preferred.
  • the total amount of fresh cement was reduced to less than 30% by weight, more particularly to less than 25% by weight, and even to less than 20% by weight, such as 8-18% or 10-15% by weight, by adding a slag to the air- curable composition.
  • the amounts of fresh Portland cement, slag and carbonated cement powder are suitably each between 10% and 30% by weight, wherein the amount of slag may be up to 35% by weight, or up to 40% by weight.
  • the amount of fresh cement is in the range of 10-23% by weight
  • the amount of carbonated cement powder is in the range of 10-25%
  • the amount of slag is in the range of 10-35%.
  • the said amounts of fresh cement, carbonated cement powder and slag are in the ranges of 10-20%, 15-25% and 15-30% by weight.
  • the ratio of carbonated cement powder to the total of cement-type ingredients is in the range of 15-45%, preferably 20-40% by weight.
  • the slag has a mean particle size that is smaller than the mean particle size of the carbonated cement powder or the fresh (Portland) cement.
  • the mean particle size is herein defined as the d50-value that may be obtained by measurements using laser diffraction, Suitable equipment thereto is supplied by Malvern Pananalytical and known as MastersizerTM 3000.
  • the slag has a d50-value below 10 pm, such as from 4-8 pm, whereas the Portland cement has a d50 value in the range of 10-20 pm and the carbonated cement powder may have a d50 value in the range of 10-30 pm, preferably 15-25 pm.
  • the air-curable composition further comprises calcium carbonate or a source thereof.
  • the amount of calcium carbonate is for instance 10-40%, such as 15- 35% by weight, preferably 20-30% by weight in a composition without slag.
  • the amount of calcium carbonate may be higher, such as from 20-50% by weight or preferably 30-50% by weight, especially when at least 10% or at least 15% slag is present in the air-curable composition.
  • the lower concentration of calcium in slag than in Portland cement gets compensated.
  • carbonated cement powder includes calcium carbonate as well, in addition to the amorphous alumina-silica gel. Therefore, the desired amount of calcium carbonate may decrease when increasing the amount of carbonated cement powder.
  • Another more preferred composition comprises Portland cement in an amount of 8-20wt%, carbonated cement powder in an amount of 20-40wt%, such as 22-36wt%, slag in an amount of 15-40%, such as 20-35%, and calcium carbonate in an amount of 20-50%.
  • the air- curable extrudable fiber cement composition further comprises fibers, for instance in an amount of up to 5% by weight, preferably up to 3% by weight, which amount do not include any fibers present in the carbonated cement powder.
  • Especially preferred amounts for each of these ranges are specified in the foregoing, and may be optimized to reduce the amount of -fresh - Portland cement to less than 20% by weight, or even in the range of 10-15% by weight.
  • the air-curable extrudable fiber cement composition comprises Portland cement in an amount between 30 and 60 % by weight (wt%), carbonated cement powder in an amount between 10 and 40 wt%, calcium carbonate in an amount between 10 to 40 wt%, wherein said amounts of cement, carbonated cement powder and calcium carbonate are based on dry weight of the fiber cement paste.
  • said contents of carbonated cement powder and calcium carbonate are each 15-35 wt%.
  • the air-curable extrudable fiber cement composition further comprises fibers, for instance in an amount of up to 5% by weight, preferably up to 3% by weight, which amount do not include any fibers present in the carbonated cement powder. Especially preferred amounts for each of these ranges are specified in the foregoing.
  • a source of silica will be present in the fiber cement composition.
  • Suitable sources of silica are for instance quartz and fly ash.
  • the total amount of silica source in the fiber cement composition is preferably in the range of 30-60% by weight based on dry weight of the fiber cement composition.
  • the silica source is provided in a molar ratio between calcium oxide (CaO) and silica (SiO2) of 0.2-1.3, more preferably 0.25-0.8 and even more preferably 0.40-0.70.
  • the added carbonated cement powder may serve as a source of calcium oxide and of silica. The effectiveness as a source may depend on its origin.
  • a low molar ratio is for instance a ratio of less than 0.70 or even less than 0.60, and preferably still higher than 0.40 or even 0.45 or more.
  • the carbonated or uncarbonated cement powder is not taken into account for calculation of this molar ratio between calcium oxide and silica.
  • Preferred autoclave-curable extrudable fiber cement compositions comprise 30-50% by weight of Portland cement, 30-50% by weight of a source of silica, i.e. SiO2, 10-30% by weight of carbonated cement powder.
  • the Portland cement and silica are preferably present in amounts of 32-45% by weight, and the carbonated cement powder is preferably present in amount up to 25% by weight, for instance 15-25% by weight.
  • the amount of added fibers is for instance up to 5% by weight, such as 3-5% by weight.
  • the extrudable fiber cement composition further comprises fibers.
  • fibers are known for fiber cement and include synthetic fibers, cellulose fibers and inorganic fibers.
  • Cellulose fibers and synthetic fibers such as polyvinyl alcohol and polypropylene are among the fibers commonly used in fiber cement production, but other fibers are not excluded.
  • Use of inorganic fibers in combination with cellulose fibers and optionally synthetic fibers may for instance be beneficial for fire resistance properties.
  • the amount of fibers in the composition is preferably in the range of 3 to 15% by weight, based on the dry weight of the fiber cement composition and excluding any - comparatively short - fibers introduced with the carbonated cement powder.
  • Preferred amounts of fibers may be in the range of 5 to 10% by weight.
  • the extrudable fiber cement composition further comprises a filler.
  • fillers to fiber cement include for instance low-density additives such as perlite and microspheres, other sources of silica, calciumsilicate and/or alumina, such as wollastonite, amorphous silica, kaolin, metakaolin, mica, aluminium trihydroxide (ATH).
  • the amount of fillers is suitably in the range of 0 to 30% by weight based on the total dry weight of the fiber cement composition, for instance 5-25% by weight, or 10-20% by weight.
  • the extrudable fiber cement composition comprises one or more pigments.
  • a product can be obtained that is mass-coloured and does not need to be coated.
  • Pigments added to fiber cement compositions may need to withstand the alkaline environment of cements and are therefore typically chosen from inorganic pigments. Most preferably but not exclusively such inorganic pigments are chosen from the group of iron oxides and titanium oxides.
  • the amount of pigment in the fiber cement composition is preferably in the range of 1-10% by weight based on the total dry weight of the fiber cement composition. An amount of up to 6wt%, or even up to 5wt% is deemed sufficient and beneficial for cost reasons.
  • the extrudable fiber cement composition may further include a variety of known additives, such as a rheology modifier or viscosity enhancement agent, a biocide, a hydrophobization agent, an air entrainment agent if any, dispersant, flocculant and so on.
  • a rheology modifier or viscosity enhancement agent such as a biocide, a hydrophobization agent, an air entrainment agent if any, dispersant, flocculant and so on.
  • Such agents are typically used in an amount of at most 1% by weight per agent (based on total dry weight of the fiber cement composition), as known per se.
  • a typical rheology modifier for cement applications, such as a fiber cement paste is a cellulose ether, and is preferably present.
  • Fig. 1(a) and (b) show DTG graphs for the carbonated and uncarbonated material; Fig 1(a) relates to autoclave-cured material, fig 1(b) relates to air-cured material.
  • the graphs for the uncarbonated samples are quite different, but both include a peak around 960 cm' 1 that can be attributed to the CSH gel. This peak has shifted and is increased in size in the carbonated samples. It furthermore is broader. This indicates a change in silicon-oxide bonding type.
  • the peak at 960 cm' 1 is representative for Ql-configuration, wherein merely one oxygen atom bonded to a silicon atom is also bonded to a further silicon atom.
  • the peak around 1045 cm' 1 is representative of a Q2-configuration, wherein two Si-O-Si bonds are present for a single Si-O-unit rather than one.
  • the peak has a shoulder around 1160 cm' 1 , that seems representative for Q3, i.e.
  • Fig 2(a) shows a peak representative for SiO2 in the carbonated and non-carbonated sample. That implies that non all quartz has been converted into the aluminate-silicate gel.
  • both graphs include peaks at 718 cm' 1 and 1414 cm' 1 that can be attributed to calcium carbonate in crystalline form.
  • the amount of SiO2 is at least 75% by weight, or even at least 80% by weight, and the amount of alumina is less, up to 12%. Furthermore, the amount of alkali metal oxides is less. This leads to an alumina-silica phase, that is richer in silica, and hence would be characterized by a stronger pozzolanic behaviour.
  • BET specific surface areas were determined by nitrogen gas adsorption (porosimetry) based on the BET isotherm. Use was made of a Quantachrome Apparatus (Autosorb iQ. Station 1) for automated gas sorption.
  • Example 8 compressive strength development of mortar formulations comprising composition 1 (waste fibre cement powder from autoclave cured material)
  • Table 6, 7 and 8 show the resulting data for the reference and the mortar formulations 11-16 for the compressive strength. All formulations include waste fibre cement powder from autoclave-cured material. Table 6 provides the absolute strength values. Table 7 shows the increase or decrease in strength relative to the reference. Table 8 shows the difference in strength between the carbonated and uncarbonated samples
  • Table 8 compressive strength difference between carbonated and uncarbonated samples.
  • the percentages are calculated as the difference in compressive strength (in MPa) between the corresponding carbonated and uncarbonated sample, divided by the compressive strength value for the uncarbonated sample.
  • Example 9 compressive strength development for samples comprising waste fibre cement powder from air-cured fiber cement
  • Table 9, 10 and 11 show the resulting data for the reference and the mortar formulations 11-16 for the compressive strength. All tables include data for samples comprising waste fibre cement powder from air-cured material. Table 9 provides the absolute strength values. Table 10 shows the increase or decrease in strength relative to the reference. Table 11 shows the difference in strength between the carbonated and uncarbonated samples.
  • Table 10 compressive strength increase or decrease relative to reference (in %)
  • Table 11 compressive strength difference between carbonated and uncarbonated samples. The percentages are calculated as the difference in compressive strength (in MPa) between the corresponding carbonated and uncarbonated sample, divided by the compressive strength value for the uncarbonated sample.
  • the compressive strength levels of the samples including waste fibre cement powder from air-cured material are consistently lower than that of the reference.
  • the decrease in strength increases with the amount of added material, both for the carbonated and the uncarbonated material.
  • the addition of carbonated waste fibre cement powder from air-cured material provides gives better result than the addition of uncarbonated material. The difference seems to biggest after 7 days for the 10% and 20% addition, after which it decreases again. For the 5% addition, the same pattern is visible, except that the biggest improvement in strength is seen after 3 days.
  • Table 10 and 11 show resulting flexural strength data for the reference in MPa and for the carbonated and uncarbonated samples.
  • Table 10 relates to the addition of (waste fibre cement powder from) autoclaved material
  • Table 11 relates to the addition of (waste fibre cement powder from) air-cured material. It is apparent from the data that the addition of carbonated autoclaved material provides the best results.
  • the flexural strength for the addition of 5% and 10% is very close to the reference value. As it was seen for the compressive strength, the flexural strength values for the 20% addition improve with age, but at 28 days the strength is still less than that of the reference.
  • the data on flexural strength have larger spread than those for compressive strength. The behaviour found for flexural strength seems generally in line with the behaviour found for compressive strength.
  • a further test sample was prepared from calcium silicate boards, which are in use as fire-resistant building boards.
  • Sample 3 was obtained from a calcium silicate board manufacturing in a Hatschek process followed by autoclave-curing and comprising 4% by weight of cellulose fibers, wherein the weight% is based on total dry weight of the composition.
  • the density of the calcium silicate board was 870 kg/m 3 when measured after drying at 105°C.
  • the cured sheets were cut in smaller pieces, after which the pieces were milled with a cutting mill (Retsch SM300 with a 500 pm sieve, and thereafter milling with a Retsch disk mill RS200 for 2 minutes) to obtain a powdered material. The material was sieved through a sieve of 100 pm.
  • Carbonation was performed batch wise as specified in Example 2 at a temperature of 60°C, relative humidity of 90%, CO2-concentration of 18 % by volume and a water/solid mass ratio of 0.35 at the start of carbonation. After carbonation, the samples were dried at 105°C for 24 hours and milled with a Retch disk mill RS200 for 30 seconds.
  • Table 11 shows that the composition of the calcium silicate board is comparable to the autoclave- cured fiber cement board, however with more CaO and less SiO2. Further characterization tests were done to determine the total organic content (TOCO, total inorganic content (TIC), CO2 content, density, specific surface area (BET) and tobermorite content. Methods were used in accordance with examples 3-6. The density was determined by pycnometry. Tobermorite content was determined by XRD. Results are shown in Table 12. Results for the powder from air-cured fiber cement is put to the right hand of the table.
  • Production waste from autoclave-cured fiber cement material with a density of 1.6 kg/dm 3 was recycled. Thereto, the material was first crushed into crushed material by means of a shredder followed by a hammer mill. The resulting material has a characteristic size from about 3 mm to 5 cm in diameter.
  • the crushed material is transported to a micronizing apparatus.
  • This apparatus comprises a vertical roller mill and an air classifier.
  • the vertical roller mill is present in a milling chamber through which the ground material may flow to the air classifier.
  • the milling chamber is heated by means of heated air flow to a temperature of approximately 70-90 °C.
  • the roller mill is operated at comparatively low pressure so as to form agglomerates of inorganic powder and fibers.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

L'invention concerne un procédé de fabrication d'un produit en fibrociment, comprenant les étapes consistant à : - fournir une pâte de fibrociment comprenant du ciment, des fibres et de l'eau ; - extruder la pâte de fibrociment pour former un article cru ; - faire durcir l'article cru pour obtenir le produit de fibrociment, la pâte de fibrociment comprenant un matériau cimentaire pouvant être obtenu par carbonatation d'un matériau cimentaire durci.
PCT/EP2024/088303 2023-12-21 2024-12-23 Procédé de fabrication d'un produit en fibrociment Pending WO2025133379A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP23219210.4 2023-12-21
EP23219210 2023-12-21
EP24183049 2024-06-19
EP24183049.6 2024-06-19

Publications (1)

Publication Number Publication Date
WO2025133379A1 true WO2025133379A1 (fr) 2025-06-26

Family

ID=94227472

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2024/088303 Pending WO2025133379A1 (fr) 2023-12-21 2024-12-23 Procédé de fabrication d'un produit en fibrociment

Country Status (1)

Country Link
WO (1) WO2025133379A1 (fr)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5891374A (en) 1994-02-01 1999-04-06 Northwestern University Method of making extruded fiber reinforced cement matrix composites
JPH11228253A (ja) * 1998-02-03 1999-08-24 Sekisui Chem Co Ltd 高強度セメント硬化体
EP2172434A1 (fr) 2008-10-02 2010-04-07 Redco S.A. Compositions de produit de fibrociment et produits formés obtenus à partir de celles-ci
WO2013082524A1 (fr) 2011-11-30 2013-06-06 James Hardie Technology Limited Matériau cimentaire extrudé léger et son procédé de fabrication
WO2018065517A1 (fr) * 2016-10-06 2018-04-12 Etex Services Nv Procédés de production de produits en fibrociment durci à l'air
KR101860848B1 (ko) * 2017-05-29 2018-05-28 한국지역난방공사 광물탄산화 공정의 탄산화된 폐콘크리트 미분말이 혼합된 건축용 압출 패널 조성물과 이를 이용한 건축용 압출 패널의 제조 공법 및 건축용 압출 패널
EP3778525A1 (fr) * 2020-06-17 2021-02-17 HeidelbergCement AG Procédé amélioré de fabrication d'un matériau cimentaire supplémentaire
US20220119319A1 (en) * 2018-11-14 2022-04-21 Etex Services Nv Carbonation of fiber cement products
WO2024003277A1 (fr) 2022-06-29 2024-01-04 Etex Services Nv Procédé et installation de recyclage de déchets de fibrociment
EP4417589A1 (fr) * 2023-06-12 2024-08-21 Swisspearl Group AG Recyclage ascendant de déchets cimentaires pour utilisation dans un produit ciment fibreux

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5891374A (en) 1994-02-01 1999-04-06 Northwestern University Method of making extruded fiber reinforced cement matrix composites
JPH11228253A (ja) * 1998-02-03 1999-08-24 Sekisui Chem Co Ltd 高強度セメント硬化体
EP2172434A1 (fr) 2008-10-02 2010-04-07 Redco S.A. Compositions de produit de fibrociment et produits formés obtenus à partir de celles-ci
WO2013082524A1 (fr) 2011-11-30 2013-06-06 James Hardie Technology Limited Matériau cimentaire extrudé léger et son procédé de fabrication
WO2018065517A1 (fr) * 2016-10-06 2018-04-12 Etex Services Nv Procédés de production de produits en fibrociment durci à l'air
KR101860848B1 (ko) * 2017-05-29 2018-05-28 한국지역난방공사 광물탄산화 공정의 탄산화된 폐콘크리트 미분말이 혼합된 건축용 압출 패널 조성물과 이를 이용한 건축용 압출 패널의 제조 공법 및 건축용 압출 패널
US20220119319A1 (en) * 2018-11-14 2022-04-21 Etex Services Nv Carbonation of fiber cement products
EP3778525A1 (fr) * 2020-06-17 2021-02-17 HeidelbergCement AG Procédé amélioré de fabrication d'un matériau cimentaire supplémentaire
WO2024003277A1 (fr) 2022-06-29 2024-01-04 Etex Services Nv Procédé et installation de recyclage de déchets de fibrociment
EP4417589A1 (fr) * 2023-06-12 2024-08-21 Swisspearl Group AG Recyclage ascendant de déchets cimentaires pour utilisation dans un produit ciment fibreux

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DE KOKERVAN ZIJL: "Extrusion of Engineered Cement-based Composite Material", PROC. 6TH RILEM SYMPOSIUM ON FRC,, January 2004 (2004-01-01), pages 1301 - 1310
KUDERSHAH, CONSTRUCTION MATERIALS, vol. 24, 2010, pages 181 - 186
ZAJAC ET AL., CEMENT AND CONCRETE RESEARCH, vol. 134, 2020, pages 106090

Similar Documents

Publication Publication Date Title
CA2821512C (fr) Composite geopolymere pour beton a ultra hautes performances
US6776838B2 (en) White pozzolan composition and blended cements containing same
CA2699903C (fr) Formulations et produits cimentaires
US20070131145A1 (en) Multi-function composition for settable composite materials and methods of making the composition
US11873262B2 (en) Inorganic binder system comprising blast furnace slag and solid alkali metal silicate
WO1999042418A1 (fr) Objet en silicate de calcium durci ayant une grande resistance
JP2022530493A (ja) オートクレーブ処理されたセメント組成物
DK2030956T3 (en) Mineral binder and a process for its preparation
WO2025133379A1 (fr) Procédé de fabrication d'un produit en fibrociment
Kishar et al. Geopolymer cement based on alkali activated slag
Abdelaal et al. Solidification of Alum Industry Waste for Producing Geopolymer Mortar
EP1373159B1 (fr) Composition de pouzzolane blanche
EP4495079A1 (fr) Matériau cimentaire, son procédé de production et son utilisation
JP4176395B2 (ja) 低比重珪酸カルシウム硬化体の製造方法
JP2002114562A (ja) 水熱硬化体およびその製造方法
JP2000191359A (ja) 軽量珪酸カルシウム板の製造方法
JP2025155890A (ja) カルシウム系炭酸化合物の製造方法、ＣａＯ含有組成物、カルシウム系炭酸化合物及び無機質成形体
JPH0813695B2 (ja) セメント混和材
WO2025204487A1 (fr) Procédé de production d'un composé carbonate à base de calcium, composition contenant du cao, composé carbonate à base de calcium et corps moulé inorganique
Mármol et al. Effect of Carbonation Curing on Fiber-Cement Products Based on Mgo-Sio2 Systems
WO2024208889A1 (fr) Matériau cimentaire supplémentaire et son procédé de fabrication
JP2023145830A (ja) ジオポリマー組成物およびその硬化物
Martinelli et al. Evaluation of the pozzolanic activity of red ceramic waste using mechanical and physicochemical methods
HK40036473A (en) Enhancing calcined clay use with inorganic binders

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24834790

Country of ref document: EP

Kind code of ref document: A1