NL2008605C2

NL2008605C2 - Concrete and mortar pre-mixture.

Info

Publication number: NL2008605C2
Application number: NL2008605A
Authority: NL
Inventors: Nicolaas Voogt; Boudewijn Piscaer
Original assignee: Cdem Minerals Group B V
Priority date: 2012-04-05
Filing date: 2012-04-05
Publication date: 2013-10-09
Also published as: WO2013151439A1

Description

Concrete and mortar pre-mixture FIELD OF INVENTION

The present invention is in the field of an pre-5 mixture to be used e.g. in concrete and mortar in order to improve characteristics of a final product, a method to obtain such an pre-mixture, a product, typically being a solid product, such as concrete, glass, and cement, comprising said premixture and use of said pre-mixture.

10 BACKGROUND OF THE INVENTION

Concrete is a composite construction material composed primarily of aggregate, cement and water, with mortar being similar thereto, however using finer aggregates. There are many formulations that have varied properties. The aggre-15 gate is generally a coarse gravel or crushed rocks such as limestone, or granite, along with a fine aggregate such as sand. The cement, commonly Portland cement, and other cementitious materials such as fly ash, blast furnace slag cement, ground calcium carbonate, etc. serve as a part of binder for 20 the aggregate. These so-called Supplementary Cementing Materials (SCMs) are recognized by the cement standard EN 197-1. Examples hereof are Silica Fume (6-10%) CEM II D, natural poz-zolan (< 35%) CEM II P and Q, fly ash (< 35%) CEM II V and W, burnt shale (< 35%) CEM II T, limestone (< 35%) CEM II L and 25 LL, blast furnace slag (< 95%) CEM III and combinations (< 55%) CEM IV & V. Origins of these SCM's are e.g. Silica fume: by product of ferro silicon metal; Pozzolan: natural volcanic earth; Fly ash: powder coal power stations; Burnt shale: lime containing bituminous shale; 30 Blast furnace slag: iron making; and Limestone: natural rock > 75% CaC03 .

Various chemical admixtures can be added to achieve varied properties. Water is thereafter mixed with this dry or moist composite which enables it to be shaped (typically 35 poured) and then solidified and hardened into rock-hard strength through a chemical process known as hydration and/or pozzolanic reaction. Concrete may be reinforced with materials that are strong in tension (often steel).

Admixtures are ingredients other than water, aggre-40 gates, hydraulic cement, and fibers that are added to the con- 2

Crete batch immediately before or during mixing, in order to change certain characteristics of the concrete, when set. Such addition is however not always practicable. A proper use of admixtures may offer certain beneficial effects to concrete, 5 including improved quality, acceleration or retardation of setting time, enhanced frost and sulfate resistance, control of strength development, improved workability, control of shrinkage, and enhanced finishability.

Admixtures may vary widely in chemical composition, 10 and may perform more than one function. Typically admixtures comprise more than one chemical/mineral compound. Two basic types of admixtures are available: chemical and mineral. All admixtures to be used in concrete construction should meet specifications; tests should be made to evaluate how the ad-15 mixture will affect the properties of the concrete to be made with the specified job materials, under the anticipated ambient conditions, and by the anticipated construction procedures .

Mineral admixtures (silica fume [SF] ) are usually 20 added to concrete in amounts to improve strength and durability resistance of concrete; and to enable a reduction in cement content.

Chemical admixtures are added to concrete in very small amounts mainly for the entrainment of air, reduction of 25 water or cement content, plasticization of fresh concrete mixtures, or control of setting time. Sometimes these chemical admixtures are referred to as modifiers.

It is noted that términology used by the person skilled in the art may vary somewhat. In this respect refer-30 ence is made to e.g. Ken W. Day; "Concrete Mix Design, quality control and specification", 2007, 3rd edition, 391 pp. Publisher: Taylor & Francis.

In this respect reference can be made to ASTM C 494, and AASHTO M 194. Air entraining admixtures are specified in 35 ASTM C 260 and AASHTO M 154. Elasticity on mortar prisms of 16x4x4 cm3 can be tested according to EN 196-1:2005.

Typically admixture dosages are less than 5% by mass of cement, i.e. at a low relative amount, and are added to the concrete at the time of batching/mixing. Some admixtures are 40 mentioned below, as well as exemplary use thereof.

3

Accelerators speed up hydration (hardening) of the concrete. Retarders slow the hydration of concrete and are used in large or difficult pours where partial setting before the pour is complete is undesirable. Air entrainments add and 5 entrain tiny air bubbles in the concrete, which will reduce damage during freeze-thaw cycles, thereby increasing the concrete's durability. Plasticizers increase the workability of plastic or "fresh" concrete, allowing it to be placed more easily, with less consolidating effort. Superplasticizers 10 (also called high-range water-reducers) are a class of plasticizers that have fewer deleterious effects and can be used to increase workability more than is practical with traditional plasticizers. Pigments can be used to change the color of concrete, for aesthetics. Corrosion inhibitors are used to mini-15 mize the corrosion of steel and steel bars in concrete. Bonding agents are used to create a bond between old and new concrete. Pumping aids improve pumpability, thicken the paste and reduce separation and bleeding.

Despite availability of various admixtures it is dif-20 ficult to use an admixture in practice, for instance due to a relative complex dosing in view of educational skills of a cement /concrete worker, in view of required characteristics, etc. Typically a highly educated person needs to be involved, which person typically is not present and can not provide in-25 formation during mixing. Even further it is difficult to provide a combination of required characteristics to a concrete, such as (relatively) high slump, limited shrinkage, limited carbonation, good chloride resistance, good microstructure and high flexural strength. It is even more difficult to tailor 30 characteristics to a concrete, by adjusting a composition of an admixture.

Therefore there still is a need for relative simple and effective admixtures and method for making the same, which admixtures can be added as such to concrete directly, which 35 increases binder properties of a concrete powder and/or (wet) sand, and which overcomes one or more of the above mentioned disadvantages without jeopardizing beneficial characteristics. SUMMARY OF THE INVENTION

The present invention relates to a method for manu-40 facturing a substantially dry concrete pre-mixture according 4 to claim 1, a substantially dry concrete pre-mixture according to claim 8, a material comprising said pre-mixture and use of said pre-mixture. It is noted that for readability the term "concrete pre-mixture" is used, which in view of the present 5 invention may also relate to "mortar pre-mixture". A mortar typically relates to a workable paste used to e.g. bind construction blocks together and fill gaps between them. It is typically applied by spreading out and is applied as a relatively thin layer.

10 The present pre-mixture may be considered to be both of chemical and mineral nature.

The present concrete or mortar may comprise >15% SCM, such as more than 20%. Further the present concrete or mortar comprises <25% pre-mixture, preferably < 15%, more preferably 15 <5%, all based on the total weight of the concrete.

In chemistry, a mixture is a material system made up by two or more different substances which are mixed together but are not combined chemically. Mixtures can be either homogeneous or heterogeneous. A homogeneous mixture is a type of 20 mixture in which the composition is uniform. A heterogeneous mixture is a type of mixture in which the components can easily be identified, as there are two or more phases present.

The present pre-mixture provides improved characteristics to e.g. concrete, such as an improved tensile strength, 25 improved strength development, good elasticity, a good slump, limited shrinkage, limited carbonation, good chloride resistance, good microstructure and high compressive strength, such as limited micro-cracking, is easy to handle, does not interfere with a concrete mixing/forming process, such as by un-30 wanted extra consumption of water e.g. due to an inherent water demand of the pre-mixture or a temperature increase due to an exothermic process, such as formation of Ca(0H)2. The premixture is substantially dry, i.e. it comprises virtually no free water, such as less than 0.1 wt. %. As a consequence the 35 pre-mixture can be handled as a powder or granule, and added as such to a concrete mixture. For addition of the pre-mixture to glass it is essential that the pre-mixture is dry. Typical particle sizes are a D50 of 1 jim-100 |im, such as 2-50 (tm, e.g. 5-20 |im.

40 It is noted that in a case when wet sand is used, 5 e.g. having a water content of less than a few percent (< 5%, preferably <3%) the amount of water in the sand may be taken into account. As a consequence the present pre-mixture may contain less than an equimolar amount of water. Such provides 5 a big advantage as there is no need to (completely) dry the sand.

The present inventors introduce some not EN 197 recognized SCM's, such as meta-kaolin calcined kaolin clay, a by-product of exothermal treated waste paper sludge, containing Meta-10 kaolin, CaO and CaC03, Ground Rice husk ash (high silica),

Sugar cane ash and VCAS Vitrified Calcium Alumina Silica waste from fiberglass.

The present pre-mixture can be tailored to required characteristics of a final product. As such, in advance, the 15 present pre-mixture can be made according to specifications.

It is noted that the present pre-mixture can be added as a ready to use mixture, providing required characteristics to a (final) product. It is therefore easy to use, especially compared to providing separate admixtures. The person skilled 20 in the art, also a less skilled person, need not worry on adjusting e.g. quantities. In view of the prior art the present pre-mixture may be considered as a technology jump.

It is noted that additives are often used in a low concentration. Such complicates mixing of dry powders. With 25 the present method and product water is used to transfer an additive to a solid carrier, i.c. a first composition. The first composition, being satisfied in water demand, is then used as a carrier to add the present pre-mixture to e.g. concrete. As a consequence the mixing is improved dramatically.

30 Thereby the effectiveness of expensive additives is increased as well, as can e.g. be seen in view of improved flexural strength.

It is noted that the cement and concrete world are used to working with standard procedures and products. With 35 the present method and pre-mixture optionally also further products, e.g. recycled products, can be incorporated into standard products- and procedures, e.g. by tailoring/modifying the present pre-mixture accordingly, such that the fit within standard procedures and products.

40 The pre-mixture comprises Ca(0H)2. The Ca(0H)2 typi- 6 cally is formed by adding water to CaO. The amount of water is preferably substantially the amount needed to satisfy the water demand of CaO. The water is preferably added slowly, e.g. in order to prevent clogging, and under stirring, e.g. in or-5 der to provide a homogeneous mixture. By homogeneous it is indicated that a chemical and physical composition of a present sample taken from the pre-mixture is similar to an average of the pre-mixture, e.g. in terms of particle size distribution, chemical composition, etc. For instance the chemical composi-10 tion does not vary more than about 2% from average, preferably less than about 1%. The average of a particle size distribution of a sample also does not vary more than 5% from average, and a variation in size (such as a) also does not vary more than about 7%.

15 Preferably a premixer is used wherein water and CaO

are mixed, and reacted. The premixer preferably has a double shaft. Therein the CaO can be added using gravity. The mixer preferably has two vertically placed troughs having each a separate shaft. The first through is preferably used to con-20 trol and finalize the reaction of the premixer. The second through is used to dry the product obtained, if necessary.

The premixing preferably takes place during an average resident time of 4-8 minutes, at a temperature of 40-60 °C. The temperature may be controlled by the flux of water.

25 Therewith the amount of residual moisture, if any, can be controlled relatively precise. Further, the CaO is reacted substantially complete into Ca(OH)2. Optionally a moisturizer is placed in the mixer to remove dust.

Using the above mixer and premixer also the present 30 first composition and optional modifier may be added and mixed. The optional modifier may be present in the water added, or as a separate component, or both. As such a homogeneous pre-mixture is provided with excellent properties.

In the pre-mixture a first composition is present, 35 the composition comprising a silica-alumina compound and/or a calcium compound. Aluminosilicate minerals (or silica alumina compounds) are minerals composed of aluminum, silicon, and oxygen, plus countercations. They are a major component of kaolin and other clay minerals.

40 The pre-mixture further comprises a modifier, in or- 7 der to improve characteristics of e.g. final concrete (i.e. after the concrete has been made and set).

DETAILED DESCRIPTION OF THE INVENTION 5 In a first aspect the present invention relates to a method for manufacturing a substantially dry concrete premixture, comprising the steps of: a) providing a first composition that as active component comprises 10 one or more silica-alumina compounds and/or one or more calcium compounds, and CaO, b) forming a homogeneous primary mixture of the first composition and calcium hydroxide with an equimolar amount of 15 water sufficient to substantially satisfy a water demand of the calcium oxide, wherein mixing preferably takes place under stirring and slow addition of water, and c) optionally providing a further modifier to the primary mixture under further mixing. The further modifier 20 preferably is a chemical modifier.

It is noted that the present pre-mixture can be considered as a pre-hydrolyzed pre-mixture, wherein a water demand is satisfied substantially. Such is advantageous as for instance when making a further material such as concrete and 25 using the present pre-mixture no additional water for satisfying a water demand of the pre-mixture needs to be taken into account; the present pre-mixture is ready to use. The premixture further relates to a reactive powder. It is noted that adjusting a water demand of a concrete mixture (e.g. for hy-30 dration of an ingredient) is undesirable, e.g. because there is no time available, it is a relatively difficult process, and it is difficult to control, especially for an operator involved. The present pre-mixture further provides for a wide range of parameters to be varied, e.g. can be used with high 35 flexibility. Further typical adjuvants of the prior art are quite expensive, contrary to the present mixture. The present dosage is very precise, e.g. in view of desired characteristics. As mentioned, prior art adjuvants are typically added as a fluid, e.g. requiring compensation for water content.

40 Below some details of the first composition are 8 given.

Table 1: Characteristics of a present first composition CHEMICAL COMPOSITION (wt. % relative to total mass) 12 3 5 CaO 19,82 20,20 18,95

Si02 18,01 17,60 18,76 A1203 10, 14 9, 90 10,56

Mg02 0, 58 0,56 0,64

Fe203 0,55 0, 64 0,52 10 S03 0,33 0,45 0,28

Na20 0,25 0,23 0,27

Ti02 0,26 0,28 0,24 K20 0,21 0,21 0,22 P205 0,10 0,11 0,10 15 Lol 47,62 48,12 47,87 (Los on Ignition) A further advantage of the present pre-mixture is that a very smooth and flat, esthetically highly valued, surface of a final product is provided. The surface also remains 20 flat and smooth over a longer period of time. Further fewer discolorations occur, which is especially appreciated when using a color for e.g. the concrete. The present pre-mixture is also relatively better distributed in a final product. Also the components of the present pre-mixture are better distrib-25 uted, both in the pre-mixture and in the final product. The present pre-mixture is very suited for capturing components from a final product, e.g. calcium (oxide), therewith preventing formation of discolorations, stains, etc. Also a denser final product can be formed.

30 In an example of the present method the modifier is one or more of a surfactant, an emulsifier, a dispersant, and a co-modifier, preferably one or more of a linear polymer containing one or more sulfonic acid groups attached to the polymer backbone such as at regular intervals, 35 such as a sulfonated melamine-formaldehyde condensate (SMF), a sulfonated naphthalene-formaldehyde condensates (SNF), a modified lignosulfonates (MLS), a polycarboxylate derivative, such as a polycarboxylate, an acrylic acid polymer, 40 a methacrylic acid polymer, 9 a maleic acid polymer, an ethylene acrylic acid polymer, a sulfonic acid polymer, an acrylamido-methyl-propane sulfonate polymer, 5 a heteropolyacid polymer, a copolymer thereof, a terpolymer thereof, and mixtures thereof.

It has been found experimentally that one or more of 10 the above compounds can be mixed into the pre-mixture efficiently and homogeneously.

In an example of the present method the first composition comprises meta-kaolin, that may or may not be in the dehydrated form of meta-kaolin. It is preferred to use a kao-15 lin or meta-kaolin compound in view of the supporting properties thereof and availability. The functional features of meta-kaolin are typically better than e.g. those of pozzolan.

In an example of the present method the calcium compounds comprise calcium carbonate and/or calcium oxide, pref-20 erably 60-70% of calcium carbonate and 40-30% of calcium oxide. Both the compounds fit very well within a process for making an pre-mixture and concrete and attribute to characteristics of a final product.

In an example of the present method the first compo-25 sition is obtained by thermal conversion of a material chosen from paper waste and residue from the paper production. It has been found that specifically waste paper sludge and residue can be used well.

In an example of the present method the amount of wa-30 ter added is from 2-30.0% w/w, preferably from 5-25% w/w, more preferably from 8-20% w/w, such as 12-15 % w/w, relative to the total weight of the pre-mixture.

The amount of water is primarily sufficient to substantially satisfy a water demand of CaO. Further oxides or other com-35 pounds reacting with water may require additional water.

In an example of the present method steps b) and c) are performed substantially simultaneously, and wherein preferably the modifier is present in the amount of water.

In a second aspect the present invention relates to a 40 substantially dry pre-mixture comprising 10 a first composition that as the active component comprises one or more silica-alumina compounds and/or one or more calcium compounds, calcium hydroxide and optionally calcium oxide, and 5 an modifier, such as one or more of a surfactant, an emulsifier, an accelerator, a retarder, an air entrainment, a plasticizer, a pigment, a corrosion inhibitor, a bonding agent, a dispersant, and a co-modifier. The modifier is preferably initially liquid. Further the modifier preferably is a 10 chemical modifier.

As mentioned in the description of the present method, by addition of an equimolar amount of water to CaO the CaO is substantially complete reacted to Ca(OH)2. Some CaO may however still be present, possibly intentional.

15 Examples of accelerators are CaCl2, Ca(N03)2 and NaN03. Examples of retarders are polyol retarders, such as sugar, sucrose, sodium gluconate, glucose, citric acid, and tartaric acid. Examples of air entrainments are abietic acid salts (Vinsol Resin), fatty acid salts, alkyl sulphates, olefin sul-20 phonates, diethanolamines, alcohol ethoxylates and betains. An example of a plasticizer is lignosulfonate. Superplasticizers typically have linear polymers containing sulfonic acid groups attached to a polymer backbone at regular intervals. Examples of superplasticizers are sulfonated naphthalene formaldehyde 25 condensate, sulfonated melamine formaldehyde condensate, acetone formaldehyde condensate, modified lignosulfonates and polycarboxylate ethers. Examples of pigments are synthetic pigments, such as red, yellow, and orange, (metal)oxides, such as brown and black iron oxides, carbon blacks, cobalt blues, 30 and chromium oxide greens. Examples of corrosion inhibitors are organic (DCS, DAS, DSS) and inorganic compounds, such as calcium nitrate based. Examples of bonding agents are a high solids, water-based emulsion, and acrylic polymer.

In an example of the present pre-mixture the modifier 35 is one or more of a linear polymer containing one or more sulfonic acid groups attached to the polymer backbone such as at regular intervals, such as a sulfonated melamine-formaldehyde condensate (SMF), a sulfonated naphthalene-formaldehyde condensates (SNF), a modi-40 fied lignosulfonates (MLS), 11 a polycarboxylate derivative, such as a polycarboxylate, an acrylic acid polymer, a methacrylic acid polymer, a maleic acid polymer, 5 an ethylene acrylic acid polymer, a sulfonic acid polymer, an acrylamido-methyl-propane sulfonate polymer, a heteropolyacid polymer, a copolymer thereof, 10 a terpolymer thereof, and mixtures thereof.

A purpose of using the above modifier is to provide flowing concrete with relatively high slump in a range of 175-225 mm, or larger. Such a concrete can e.g. be used in heavily 15 reinforced structures, in placements where adequate consolidation by vibration cannot be readily achieved, and in providing high-strength concrete at a water-powder ratio ranging from 0.15 to 0.5, preferably from 0.15-0.3. The powder preferably has particles with a D50 < 125 pm.

20 It is noted that in order to increase slump of con crete such depends on factors as the type, dosage, and time of addition of a modifier, water-cement ratio and the nature or amount of cement. A person skilled in the art will be able using standard tests to determine suitable amounts, suitable 25 modifiers, etc., contrary to e.g. a worker actually making the concrete.

It is an objective of the present invention to reduce water requirements, e.g. by 10-30%. A high-strength concrete with e.g. low permeability is provided. Flexural strengths 30 greater than 70 MPa at 28 days have been attained.

A problem associated with using a SCM in concrete may be slump loss. The present modifier however still provides good or superior slump, e.g. of 245 or more.

Typically in prior art the slump loss problem is 35 overcome by adding the pre-mixture to the concrete just before the concrete is placed. However, there are disadvantages to such a procedure. The dosage control, for example, is not adequate. Further, the addition is complex, e.g. it requires ancillary equipment. An option is to add pre-mixtures at the 40 batch plant. Such may provide dosage control improvement. Fur- 12 ther it may reduce wear of mixers. Even more preferred, however, is to add a present pre-mixture comprising a required dose.

Examples of polycarboxylates are available from IN-5 TERPOLYMER such as Rohagit® and Acrytex®, now sold under the trademark SYNTRAN®. Several additional polycarboxylates, including terpolymers, are now available. Similar products can be purchased from BASF. Homopolymers of acrylic acid polymers, such as SYNTRAN ® 8000 series, having a Total Solids of 20-50 10 wt.%, a pH (25°C) of 2-8.5, a Molecular Weight (GPC) of 2500- 150000, a Brookfield Viscosity [mPa.s] of 20-7000 and optionally a neutralizing agent, such as NaOH, and NH4OH.

Copolymers of acrylic acid and methacrylic acid or maleic acid or ethylene acrylic acid or sulfonic acid or Acrylamido-15 methyl-propane sulfonate polymers or heteropolyacid, such as SYNTRAN ® 8400 and 8500 series, having a Total Solids of 30-50 wt.%, a pH (25°C) of 2-9, a Molecular Weight (GPC) of 4000-60000, a Brookfield Viscosity [mPa.s] of 40-3000 and optionally a neutralizing agent, such as NaOH, and NH4OH.

20 Terpolymers of acrylic acid and two or methacrylic acid, maleic acid, ethylene acrylic acid, sulfonic acid, acrylamido-methyl-propane sulfonate polymer, heteropolyacid, t-bis-dialkylamino acid, such as SYNTRAN ® 8700 and 8800 series, having a Total Solids of 35-45 wt.%, a pH (25°C) of <2-7.5, a 25 Molecular Weight (GPC) of 4000-24000, a Brookfield Viscosity [mPa.s] of 50-8000 and optionally a neutralizing agent, such as NaOH, and NH40H.

In an example of the present pre-mixture the first composition comprises meta-kaolin, that may or may not be in 30 the dehydrated form of meta-kaolin and/or wherein the calcium compounds comprise calcium carbonate and/or calcium oxide, preferably 60-70% of calcium carbonate and 40-30% of calcium oxide, and/or wherein the first composition is obtained by thermal conver-35 sion of a material chosen from paper waste and residue from the paper production.

Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si205 (OH)4. From kaolinite endothermic dehydroxylation (or alternatively, 40 dehydration) beginning at 550-600 °C produces disordered meta- 13 kaolin, Al2Si207. Metakaolin is not a simple mixture of amorphous silica (Si02) and alumina (AI2O3) , but rather a complex amorphous structure that retains some longer-range order (but not strictly crystalline) due to stacking of its hexagonal 5 layers. The largest use is in the production of paper, including ensuring the gloss on some grades of paper. Commercial grades of kaolin are supplied and transported as dry powder, semi-dry noodle or as liquid slurry.

Thus, kaolin and metakaolin are considered as silica-alumina 10 compounds also forming part of a sorbent obtained from paper-waste or the like.

In a third aspect the present invention relates to a material, such as concrete, mortar, glass, cement, and wet sand, comprising an pre-mixture according to the invention.

15 In a fourth aspect the present invention relates to a use of an pre-mixture according to the invention in concrete or mortar for improving one or more of hardness, durability, flowability, slump, microstructure, processability, permeability, shrink behavior, slump retention, bending tensile 20 strength, water reduction, set-retardation, acceleration, plasticization, air entrainment, neutralization of surface charge, dispersion, agglomeration, viscosity, strength, flexural strength, pumpability, and self-healing properties, or in a sorbent, such as a sorbent of a metal, such as mercury. It 25 has been found that the present pre-mixture increases the uptake of metal, e.g. of mercury, and/or makes the uptake more efficient, or in wet sand.

In a fifth aspect the present invention relates to a dry bagged concrete or mortar comprising a pre-mixture accord-30 ing to the invention. By adding water and mixing the concrete or mortar is ready to use.

14 EXPERIMENTS_

Topcrete__7A 7B 7C

_ 25-1-2012 25-1-2012 25-1-2012

No____ CEMENT: (kg)_ mortel mortel mortel

Sperwer 42,5R 360 32Ö 320

Topcrete + 15% water___40_

Topcrete + 18,7% optima 200____

Topcrete + 23% premia 194____40

Water eff. 170 164+(6) 130 + (4) water in Topcrete___6,00 4,00

Suppletion:____

Sand 60 - 05____

Sand 65-05__100% 100% 100%

Measurement____

Slump (EN 206-1:2000) (mm)____160

Slump 1 hour____

Hagermann (mm)__230 160 245

Temperatuur__20 20 20

Flexural Strength (ASTM C 293)____ 1 day strength (MPa)__13,5 10,2 14,9

Flexural Strength:__3J__3J__3,3 28 days strength (MPa)__63,8 54,2 73,1

Flexural strength__5$__5$__7,1 RESULT__stable stable stable

The present concrete mixture fall in a slump class S5 (EN 206-1:2000), that is having the highest slump..

5 The Flexural strength is determined by CENTER point load-ing(ASTM C 293). The concrete is consolidated by vibration (ASTM C31) and tap sizes to release air pockets. For higher slump, after rodding, molds are tapped to release air pockets and spade along the sides to consolidate. The standard devia-10 tion is about 5%.

Claims

1. Werkwijze voor het vervaardigen van een in hoofdzaak droog voormengsel voor beton of mortel, omvattende de stappen van: a) het verschaffen van 5 een eerste samenstelling die als werkzame component één of meer silica-alumina verbindingen en/of één of meer calciumverbindingen omvat, en CaO, b) het vormen van een homogeen eerste mengsel van de 10 eerste samenstelling en calciumhydroxyde met een equimolaire hoeveelheid water die voldoende is om in hoofdzaak aan een waterbehoefte van het calciumoxyde te voldoen, waarbij het mengen bij voorkeur onder roeren en langzame toevoeging van water plaatsvindt, en 15 c) eventueel het verschaffen van een verder modifica- tiemiddel aan het primaire mengsel onder verder mengen.Method for manufacturing a substantially dry premix for concrete or mortar, comprising the steps of: a) providing a first composition comprising as active component one or more silica-alumina compounds and / or one or more calcium compounds and CaO, b) forming a homogeneous first mixture of the first composition and calcium hydroxide with an equimolar amount of water sufficient to substantially satisfy a water requirement of the calcium oxide, the mixing preferably with stirring and slow addition of water takes place, and c) optionally providing a further modifier to the primary mixture with further mixing.

2. Werkwijze volgens conclusie 1, waarbij het modifi-catiemiddel één of meer van een oppervlakactieve stof, een emulgator, een versneller, een vertrager, een luchtinsluiter, 20 een weekmaker, een pigment, een corrosieremmer, een bindmiddel, een dispergeermiddel, en een co-modificatiemiddel, bij voorkeur één of meer van een lineair polymeer met één of meer sulfonzuurgroepen aan het polymeerskelet, zoals met regelmatige intervallen, zoals een 25 gesulfoneerd melamine-formaldehyde condensaat (SMF), een ge- sulfoneerd naftaleen-formaldehyde condensaat (SNF), een aangepaste lignosulfonaat (MMA), een polycarboxylaatderivaat, zoals een polycarboxylaat, een acrylzuurpolymeer, 30 een methacrylzuurpolymeer, een maleïnezuurpolymeer, een ethyleenacrylzuurpolymeer, een sulfonzuur polymeer, een acrylamido-methyl-propaansulfonaat polymeer, 35 een heteropolyzuur polymeer, een copolymeer daarvan, een terpolymeer daarvan, en - 16 - mengsels daarvan.2. Method according to claim 1, wherein the modifier comprises one or more of a surfactant, an emulsifier, an accelerator, a retarder, an air trap, a plasticizer, a pigment, a corrosion inhibitor, a binder, a dispersant, and a co-modifier, preferably one or more of a linear polymer with one or more sulfonic acid groups on the polymer backbone, such as at regular intervals, such as a sulfonated melamine-formaldehyde condensate (SMF), a sulfonated naphthalene-formaldehyde condensate (SNF) , a modified lignosulfonate (MMA), a polycarboxylate derivative, such as a polycarboxylate, an acrylic acid polymer, a methacrylic acid polymer, a maleic acid polymer, an ethylene acrylic acid polymer, a sulfonic acid polymer, an acrylamido-methyl-propane sulfonate polymer, a heteropolymeric polymer thereof, a heteropolymeric acid polymer terpolymer thereof, and mixtures thereof.

3. Werkwijze volgens één der voorgaande conclusies, waarbij de eerste samenstelling omvat meta-kaolien, die al dan niet in de gedehydrateerde vorm van meta-kaolien is.A method according to any one of the preceding claims, wherein the first composition comprises meta-kaolin, whether or not in the dehydrated form of meta-kaolin.

4. Werkwijze volgens één der voorgaande conclusies, waarbij de calcium verbindingen omvatten calciumcarbonaat en/of calciumoxide, bij voorkeur 60-70% calciumcarbonaat en 40-30% calciumoxide.A method according to any one of the preceding claims, wherein the calcium compounds comprise calcium carbonate and / or calcium oxide, preferably 60-70% calcium carbonate and 40-30% calcium oxide.

5. Werkwijze volgens één der voorgaande conclusies, 10 waarbij de eerste samenstelling wordt verkregen door thermische conversie van een materiaal gekozen uit papierafval en residu van de productie van papier.5. A method according to any one of the preceding claims, wherein the first composition is obtained by thermal conversion of a material selected from waste paper and residue from the production of paper.

6. Werkwijze volgens één der voorgaande conclusies, waarbij de hoeveelheid toegevoegd water is 2-30,0% w/w, bij 15 voorkeur 5-25% w/w, liever 8-20% w/w, zoals 12 - 15% w/w, betrokken op het totale gewicht van het voormengsel.6. A method according to any one of the preceding claims, wherein the amount of added water is 2-30.0% w / w, preferably 5-25% w / w, more preferably 8-20% w / w, such as 12-15% w / w, based on the total weight of the premix.

7. Werkwijze volgens één der voorgaande conclusies, waarbij de stappen b) en c) nagenoeg gelijktijdig uitgevoerd worden, en waarbij bij voorkeur het modificatiemiddel aanwezig 20 is in de hoeveelheid water.7. A method according to any one of the preceding claims, wherein steps b) and c) are carried out substantially simultaneously, and wherein preferably the modifier is present in the amount of water.

8. In hoofdzaak droog voormengsel omvattende een eerste samenstelling die als werkzame component één of meer silica-alumina verbindingen en/of één of meer calciumver-bindingen omvat, 25 calciumhydroxyde en eventueel calciumoxide, en een modificatiemiddel, zoals één of meer van een oppervlakac-tieve stof, een emulgator, en een dispergeermiddel.8. Substantially dry premix comprising a first composition comprising as active ingredient one or more silica-alumina compounds and / or one or more calcium compounds, calcium hydroxide and optionally calcium oxide, and a modifier such as one or more of a surface active substance, an emulsifier, and a dispersant.

9. Voormengsel volgens conclusie 8, waarbij het modi-ficatiemiddel één of meer is van 30 een lineair polymeer met één of meer sulfonzuurgroepen aan het polymeerskelet, zoals met regelmatige intervallen, zoals een gesulfoneerd melamine-formaldehyde condensaat (SMF), een ge-sulfoneerd naftaleen-formaldehyde condensaat (SNF), een aangepaste lignosulfonaat (MMA), 35 een polycarboxylaatderivaat, zoals een polycarboxylaat, een acrylzuurpolymeer, een methacrylzuurpolymeer, een maleïnezuurpolymeer, een ethyleenacrylzuurpolymeer, 40 een sulfonzuur polymeer, - 17 - een acrylamido-methyl-propaansulfonaat polymeer, een heteropolyzuur polymeer, een copolymeer daarvan, een terpolymeer daarvan, en 5 mengsels daarvan.9. Premix according to claim 8, wherein the modifier is one or more of a linear polymer with one or more sulfonic acid groups on the polymer backbone, such as at regular intervals such as a sulfonated melamine-formaldehyde condensate (SMF), a sulfonated naphthalene-formaldehyde condensate (SNF), an adapted lignosulfonate (MMA), a polycarboxylate derivative, such as a polycarboxylate, an acrylic acid polymer, a methacrylic acid polymer, a maleic acid polymer, an ethylene acrylic acid polymer, 40 a sulfonic acid polymer, -17-methyl-a-propylene sulfate polymer , a heteropoly acid polymer, a copolymer thereof, a terpolymer thereof, and mixtures thereof.

10. Voormengsel volgens conclusie 8 of 9, waarbij de eerste samenstelling kaolien omvat, dat al dan niet in de gedroogde vorm van meta-kaolien is en/of waarbij de calcium verbindingen omvatten calciumcarbonaat 10 en/of calciumoxide, bij voorkeur 60-70% calciumcarbonaat en 40-30% calciumoxyde, en/of, waarbij de eerste samenstelling wordt verkregen door thermische conversie van een materiaal gekozen uit papierafval en residu van de productie van papier.10. Premix as claimed in claim 8 or 9, wherein the first composition comprises kaolin, whether or not in the dried form of meta-kaolin and / or wherein the calcium compounds comprise calcium carbonate 10 and / or calcium oxide, preferably 60-70% calcium carbonate and 40-30% calcium oxide, and / or, wherein the first composition is obtained by thermal conversion of a material selected from paper waste and paper production residue.

11. Materiaal, zoals beton, mortel, glas, cement en nat zand, omvattende een voormengsel volgens een der conclusies 8-10.A material, such as concrete, mortar, glass, cement and wet sand, comprising a premix according to any one of claims 8-10.

12. Gebruik van een voormengsel volgens één der conclusies 8-10 in beton of mortel voor het verbeteren van één of 20 meer van hardheid, duurzaamheid vloeibaarheid, uitvloeien, microstructuur, verwerkbaarheid, permeabiliteit, krimpgedrag, uitvloeiretentie, buigtreksterkte, water vermindering , zet-vertraging, versnelling, plasticering, luchtinsluitingen, neutralisering van oppervlaktelading, dispersie, agglomeratie, 25 viscositeit, sterkte, buigsterkte, verpompbaarheid, weerstand tegen chloride, carbonaatvorming, en zelfherstellende eigenschappen, of in een sorbent, zoals een sorptiemiddel van een metaal, zoals kwik, of in nat zand.12. Use of a premix according to any one of claims 8-10 in concrete or mortar for improving one or more of hardness, durability fluidity, flow-out, microstructure, processability, permeability, shrink behavior, flow retention, flexural tensile strength, water reduction, setting deceleration, acceleration, plasticization, air inclusions, neutralization of surface charge, dispersion, agglomeration, viscosity, strength, flexural strength, pumpability, resistance to chloride, carbonate formation, and self-healing properties, or in a sorbent, such as a metal sorbent, such as mercury, or in wet sand.

13. Zak droog beton of mortel omvattende een voor-30 mengsel volgens één der conclusies 8-10.13. Bag of dry concrete or mortar comprising a premix according to any one of claims 8-10.