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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
  • B29C33/60—Releasing, lubricating or separating agents
  • B29C33/62—Releasing, lubricating or separating agents based on polymers or oligomers
• • 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
  • C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
  • C04B40/0028—Aspects relating to the mixing step of the mortar preparation
  • C04B40/0039—Premixtures of ingredients

Definitions

• the present invention is the use of an additive as a formwork aid in the use of building chemical compositions.
• German patent DE 25 10 224 a process for the production of concrete objects using a special concrete additive is described, which contributes to increase the early strength.
• This patent also includes a concrete admixture which is a stable suspension of 10 to 50% by weight of finely divided silica having a preferred particle diameter of colloidal silica ⁇ 0.1 ⁇ m.
• WO 2004/002915 A2 calcium silicate hydrate or else a silica with high surface area added. Both accelerators may additionally contain alkali metals.
• a concrete composition which, in addition to the hydraulic binder, also contains aggregates, water, silica sol and a superplasticizer in the form of a polycarboxylate, is known from WO 01/90024 A1.
• the silica sol used here is cationically stabilized and has a particle size between 2 and 200 nanometers. Their use is intended to prevent bleeding and at the same time not affect the processability of the concrete composition too much.
• the European application EP 0 931 030 A1 describes a process for the production of concrete or mortar with increased early strength with a simultaneously good fatigue strength.
• a mixture consisting of a hydraulic binder, aggregates, water and colloidal silica is prepared, wherein the relative standard deviation of the particle size of the colloidal silica is at least 30%.
• WO 01/98210 A1 claims a defined silica sol composition comprising a first silica sol component having a broad particle size distribution and a second silica sol component having a narrow particle size spectrum. Also included is the use of such compositions, as additives to concrete or mortar, as well as concrete and mortar compositions which, in addition to hydraulic binders, aggregates and water, also contain a silica sol composition of said grain size distributions.
• colloidal silica components as additive to cementitious materials is described by WO 2004/035473 A1.
• the silica components used in this context must have been prepared by a specific process wherein at least one silane component is mixed with colloidal silica particles in the weight ratio of silane to silica component of about 0.003 to 0.2.
• the silica dispersion obtainable in this way has a silica content of at least 20% by weight.
• the main disadvantage when stripping precast concrete parts is that the adhesion forces between the building chemical mass and the shuttering material can still not be sufficiently reduced so that damage or partial destruction of the components can be avoided.
• the object of the present invention was therefore to provide an additive with which mixed-bodied masses can be better processed in the on-state and / or can be more easily switched off in the (partially) cured state.
• the decisive aspect was to minimize the reject rate and to facilitate the shifting of the shuttering elements during line production. As far as possible, it should be possible to dispense with strength-reducing additives.
• the desired effects according to the task can be achieved both by inorganic and by organic compounds and their arbitrary mixtures.
• the respective additives are essentially not limited to strictly defined compounds, but rather that the respective representatives can be selected from an unsuspectedly large number of suitable compounds.
• the present invention provides as preferred component 1.1 an aluminum-modified colloidal silica wherein the colloidal silica is in particular silica sol ("silica sol"), precipitated silica, silica gel and finely divided silica.
• silica sol silica sol
• precipitated silica silica gel
• finely divided silica finely divided silica
• stable dispersion or sol of amorphous silica type having a preferred particle size of 0.001 to 100 microns, a particularly preferred particle size of 0.01 to 30 microns, and a most preferred particle size of 0.1 to 15 microns
• colloidal silica is considered in accordance with the present invention as defined by K. Her, as reported in “The Colloidal Chemistry of Silica” Chapter 4, Wiley & Sons (1979, p 312) Substantive component of the present invention.
• component 1.2 should in particular be polymers of hydroxyalkyl (meth) acrylate, acrylamide, methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), methyl methacrylate, methyl acrylate, butyl acrylate or cyclohexyl acrylate, which are particularly preferably in each case in part - or fully cross-linked form should be available.
• hydroxyalkyl (meth) acrylate acrylamide, methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), methyl methacrylate, methyl acrylate, butyl acrylate or cyclohexyl acrylate, which are particularly preferably in each case in part - or fully cross-linked form should be available.
• AMPS 2-acrylamido-2-methylpropanesulfonic acid
• Water-soluble or at least partially water-soluble polyvinyl alcohols which should preferably be present in partially saponified form and which are particularly preferred have a saponification degree of 60 to 96%, are considered in the context of the present invention as preferred representatives of component 1.3.
• Particularly suitable are polyvinyl alcohols having a saponification degree of from 85% to 96%, particularly preferably from 90 to 96%.
• the polyvinyl alcohols should have an average molecular weight between 20,000 and 80,000, preferably between 25,000 and 70,000, and particularly preferably between 30,000 and 65,000.
• Preferred components 1.4 used in the context of the present invention are polymer compounds having the general composition
• V NH or oxygen
• X halogen, C 1 to C 4 alkyl sulfate or d-bis
• R 1 , R 2 and R 3 , M and a are as defined above,
• R 12 1 wherein at least one radical R 10 , R 11 and / or R 12 must be present, and a saturated or unsaturated, linear or branched, aliphatic hydrocarbon radical having 1 to 40 C atoms
• R 10 H 1 C 1 -C 4 -AlkVl- , Phenyl, benzyl, C 1 -C 4 -alkoxy,
• Halogen, cyano, -COOH, -COOR 5 , -CO-NH 2 , -OCOR 5 R 11 arylalkyl group with C 1 -C 12 -alkyl, linear or branched, and C 6 -
• C 14 aryl radical R 12 alkylaryl group with C 1 -C 12 -alkyl, linear or branched, and C 6
• component 1.4 up to 50 mol% of the components a) in component 1.4 are replaced by other sulfo-containing structural units derived from methallylsulfonic acid or allylsulfonic acid monomers.
• the component 1.4 can according to the present invention also from 30 to 80 mol%, preferably 35 to 70 mol%, of the assembly a), 5 to 55 mol%, preferably 10 to 45 mol% of the assembly b), 2nd to 30 mol%, preferably 5 to 25 mol%, of the assembly c) and / or 0.2 to 15 mol%, preferably 0.5 to 10 mol%, of the assembly d).
• the present invention comprises a further variant of component 1.4 which has a number-average molecular weight of 50,000 to 10,000,000 g / mol.
• the proposed additive should find use as a formwork aid, in particular when using construction-chemical compositions containing at least one member of the series hydraulic binder, filler, accelerator and dispersing additive.
• the proposed additive can also be used according to the invention in building chemical compositions, which further contain functional additives.
• Particularly positive effects succeed with the use according to the invention in connection with construction chemical compositions containing as hydraulic binder cement, lime, gypsum, anhydrite or other calcium sulfate-based binder, with cements of type CEM I to CEM V and aluminate cements and any mixtures thereof as are particularly preferred.
• the present invention takes into account dispersing additives in the form of a water reducer and / or a superplasticizer according to standard EN 934/2.
• dispersing additives in the form of a water reducer and / or a superplasticizer according to standard EN 934/2.
• fillers also already mentioned representatives have been found to be particularly suitable, which have a particle size of 0.1 to 100 mm.
• the respective additive can be added to the mixing water and introduced with this in the bauchemische raw mass.
• the additive which is to be used according to the invention as a formwork aid can also be applied to the boundary layer of the formwork prior to introduction of the construction chemical raw material into the formwork.
• a use variant is also included in the present invention, in which the additive is used as a formwork removal aid in the production of precast concrete parts, preferably for the production of green-strength-resistant and in particular prestressed precast concrete parts.
• the concrete to be characterized is freshly prepared and transferred immediately after mixing in a corresponding Gleitform (open top and bottom mold of the corresponding molded part, which is closed at the front and provided at the rear with a removable closure) and compacted by appropriate vibration.
• the front side of the slipform is connected to a dynamometer by a steel cable and this with a corresponding hand crank.
• Fi describes the measurand of the dynamometer, which is needed to set the slipforming in motion for the first time
• Ffb describes the measurand of the dynamometer in order to move the slipform at a constant speed.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Moulds, Cores, Or Mandrels (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
• Forms Removed On Construction Sites Or Auxiliary Members Thereof (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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• 2005
  • 2005-12-01 DE DE102005057507A patent/DE102005057507A1/de not_active Withdrawn
• 2006
  • 2006-11-30 EP EP06829223A patent/EP1963239A2/de not_active Withdrawn
  • 2006-11-30 AU AU2006319360A patent/AU2006319360A1/en not_active Abandoned
  • 2006-11-30 WO PCT/EP2006/011532 patent/WO2007062854A2/de active Application Filing
  • 2006-11-30 JP JP2008542673A patent/JP2009517317A/ja not_active Withdrawn
  • 2006-11-30 CN CNA200680045372XA patent/CN101321711A/zh active Pending

Non-Patent Citations (1)

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