EP0839123A1 - Calcium hydroxide re-alkalization method - Google Patents
Calcium hydroxide re-alkalization methodInfo
- Publication number
- EP0839123A1 EP0839123A1 EP97919236A EP97919236A EP0839123A1 EP 0839123 A1 EP0839123 A1 EP 0839123A1 EP 97919236 A EP97919236 A EP 97919236A EP 97919236 A EP97919236 A EP 97919236A EP 0839123 A1 EP0839123 A1 EP 0839123A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- concrete
- alkaline
- reinforcement
- ions
- top layer
- 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.)
- Withdrawn
Links
- 238000000034 method Methods 0.000 title claims abstract description 33
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 title claims abstract description 5
- 239000000920 calcium hydroxide Substances 0.000 title claims abstract description 5
- 229910001861 calcium hydroxide Inorganic materials 0.000 title claims abstract description 5
- 239000004567 concrete Substances 0.000 claims abstract description 42
- 230000008569 process Effects 0.000 claims abstract description 19
- 230000002787 reinforcement Effects 0.000 claims abstract description 16
- 239000004568 cement Substances 0.000 claims abstract description 9
- 238000005260 corrosion Methods 0.000 claims abstract description 9
- 230000007797 corrosion Effects 0.000 claims abstract description 9
- 238000001035 drying Methods 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 150000002500 ions Chemical class 0.000 claims description 11
- 230000005684 electric field Effects 0.000 claims description 6
- 230000037427 ion transport Effects 0.000 claims description 5
- 230000032258 transport Effects 0.000 claims description 5
- 239000012071 phase Substances 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 239000012808 vapor phase Substances 0.000 claims description 2
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims 3
- 239000004744 fabric Substances 0.000 claims 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims 1
- 230000004913 activation Effects 0.000 claims 1
- 230000004069 differentiation Effects 0.000 claims 1
- 238000004090 dissolution Methods 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- 238000002161 passivation Methods 0.000 claims 1
- 238000004321 preservation Methods 0.000 claims 1
- 238000004088 simulation Methods 0.000 claims 1
- 230000001960 triggered effect Effects 0.000 claims 1
- 239000011150 reinforced concrete Substances 0.000 abstract description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 abstract 2
- 229910000831 Steel Inorganic materials 0.000 abstract 2
- 239000010959 steel Substances 0.000 abstract 2
- 230000003213 activating effect Effects 0.000 abstract 1
- 239000001569 carbon dioxide Substances 0.000 abstract 1
- 229910002092 carbon dioxide Inorganic materials 0.000 abstract 1
- 238000010276 construction Methods 0.000 abstract 1
- 239000004035 construction material Substances 0.000 abstract 1
- 238000002848 electrochemical method Methods 0.000 abstract 1
- 230000007613 environmental effect Effects 0.000 abstract 1
- 238000009439 industrial construction Methods 0.000 abstract 1
- 239000011148 porous material Substances 0.000 abstract 1
- 230000003014 reinforcing effect Effects 0.000 abstract 1
- 239000011435 rock Substances 0.000 abstract 1
- 230000007246 mechanism Effects 0.000 description 4
- 239000011575 calcium Substances 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- KJFMBFZCATUALV-UHFFFAOYSA-N phenolphthalein Chemical compound C1=CC(O)=CC=C1C1(C=2C=CC(O)=CC=2)C2=CC=CC=C2C(=O)O1 KJFMBFZCATUALV-UHFFFAOYSA-N 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- -1 hydroxyl ions Chemical class 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/4505—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements characterised by the method of application
- C04B41/4564—Electrolytic or electrophoretic processes, e.g. electrochemical re-alkalisation of reinforced concrete
- C04B41/4566—Electrochemical re-alcalisation
Definitions
- the carbonation area of the concrete edge zone (3-5cm concrete top layer with reinforcement layer) is found as a scattering area at a depth of up to approx. 30mm. Greater carbonation depths are rare and more than 40-50mm are practically never reached.
- the purpose of the CH realizing process is to comprehend the above mentioned realizing processes observed in nature and to restore the alkaline milieu in the already carbonated concrete and in the reinforcement area Mittel electrochemically supported wet / dry cycles, the behavior in nature is reproduced in a time-lapse process and the carbonated edge zone area is restored to an alkaline state (realized).
- the concrete surface can be provided with a seal in order to permanently maintain the realization
- the cement stone in the finished concrete contains 10-15 vol% calcium hydroxide Ca (OH) 2 (gel water), corresponding to approx. 30-45 liters per m 3 concrete at carbonation depths of 20mm ( Carbonation Ca (OH) 2 + CO2 -> CaC ⁇ 3 + H2O) the concrete lacks about 0 5-1 liters per m 2 of surface in the upper layer.
- the task of the CH realizing process is then to compensate for this deficiency from the core concrete reservoir
- anode mats in the form of flooding cassettes or saturated, water-holding porous mats with inserted electrically conductive tissue in different sizes depending on the flat are attached to the concrete surface and connections for reinforcement are made as cathodes.
- substances that improve conductivity are added to the water in the anode mat (for example potassium carbonate).
- the electric field (E field) is built up with DC driving voltages of 10-50 volts, with a current of 3 depending on the object -5 A / m 2 concrete surface (approx. 2 A / m 2 reinforcement).
- the E fields are to be adapted to the building conditions and requirements of the concrete surface, taking into account the building integration
- the proof of effectiveness of the realcalization is carried out by checking the new alkalinity in the concrete top layer in 5mm layers and comparing it with the status before carrying out the process.
- the aim is to restore the alkalinity at least 100%
- the drawing shows the concrete edge zone of a wall facade with reinforcement and carbonated concrete top layer.
- the arrangement of the E-field with anode mat, rectifier and reinforcement connection as well as the ion migration taking place with repassivation of the reinforcement surface and reactions are shown and the running mechanisms are given
Landscapes
- Chemical & Material Sciences (AREA)
- Electrochemistry (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Working Measures On Existing Buildindgs (AREA)
Abstract
A method is presented for restoring the alkaline environment in carbonatized top layers of concrete, by activating the calcium hydroxide contained in the concrete. By analogy to observed natural processes, an electrochemical method is described that is intended to re-alkalize the carbonatized top layer, and re-passivate the steel reinforcements that are no longer protected from corrosion by an alkaline environment by means of drying/humidification cycles. This method presupposes parts made of conventional concrete, having the components hardened cement paste, rock aggregate, and capillary pores. The alkaline cement paste, with a pH value of 11-13, is altered chemically over time to carbonatized cement paste with a pH value below 9-10, under the influence of atmospheric carbon dioxide. In contrast to alkaline cement paste, the latter offers no protection against corrosion to the steel reinforcing rods that are immersed in the concrete in reinforced-concrete structures. Increasing risks of corrosions result for civil and structural engineering constructions such as bridges and in industrial constructions. Early recognition of the problem, and restoration of the alkaline environmental conditions for the concrete reinforcements, which protect them from corrosion, contribute to preserving the durability of the construction material.
Description
CALCIUMHYDROXID-REALKALISIER VERFAHRENCALCIUM HYDROXIDE REALCALIZER PROCEDURE
1. Beschreibung1. Description
Die Grundlagen elektrochemischer Realkaiisierungsverfahren sind in einer Vielzahl von Veröffentlichungen enthalten. Daher ist das Vorgehen an sich als bekannt voraus¬ zusetzen. Z.B. Korrosionsschutztechnische Problemdarlegungen inThe basics of electrochemical realization methods are contained in a large number of publications. The procedure itself must therefore be assumed to be known. For example, Explanation of corrosion protection problems in
- 'Korrosion und Korrosionsschutz (Teil 5), elektrochemische Schutzverfahren für Stahlbetonbauwerke' Dokumentation D065 des Schweizerischen Ingenieur- und Architekten verems Zürich- 'Corrosion and corrosion protection (part 5), electrochemical protection processes for reinforced concrete structures' Documentation D065 by the Swiss engineer and architect verems Zurich
1.1 Verfahrensqrundsätze1.1 Procedural principles
1.1.1 Betonkarbonatisierung und Realkaiisierung in der Natur:1.1.1 Concrete carbonation and real quaying in nature:
Der Karbonatisierungsbereich der Betonrandzone (3-5cm Betonoberschicht mit Beweh¬ rungslage) wird als Streubereich in einer Tiefe bis ca. 30mm angetroffen. Grossere Karbonatisierungstiefen sind selten und mehr als 40-50mm werden praktisch nie erreicht.The carbonation area of the concrete edge zone (3-5cm concrete top layer with reinforcement layer) is found as a scattering area at a depth of up to approx. 30mm. Greater carbonation depths are rare and more than 40-50mm are practically never reached.
Horizontal verlaufende Betonoberflachen haben hingegen selten eine grossere Karbo- natisierungstiefe als 3-7mm. Der Grund hegt im Feuchte- und Austrocknungsverhalten solcher Betonrandzonen unter natürlicher Bewitterung. Es resultieren feuchteabhängige lonentransporte und Diffusionserscheinungen in der Betonrandzone unter Bildung von mehr oder weniger ausgeprägten Dichtzonen in der unmittelbaren Betonoberschicht Dieses Verhalten führt in Nasszeiten zu einem steten naturlichen Realkalisiervorgang, unterbrochen durch Karbonatisierung in TrockenzeitenConversely, horizontal concrete surfaces rarely have a greater carbonation depth than 3-7mm. The reason lies in the moisture and drying behavior of such concrete edge zones under natural weathering. This results in moisture-dependent ion transport and diffusion phenomena in the concrete edge zone with the formation of more or less pronounced sealing zones in the immediate concrete top layer. This behavior leads to a constant natural realizing process in wet times, interrupted by carbonation in dry periods
1.1.2 Verfahrensableitung aus dem Naturvorgang1.1.2 Deriving processes from the natural process
Das CH-Realkalisierverfahren bezweckt ein zeitlich gerafftes Nachvollziehen der genannten, in der Natur beobachteten Realkalisiervorgange und Wiederherstellen des alkalischen Milieus im bereits karbonatisierten Beton und im Bewehrungsbereich Mittels
elektrochemisch unterstützter Nass- /Trockenzyklen wird das Verhalten in der Natur im Zeitrafferverfahren nachvollzogen und der karbonatisierte Randzonenbereich wieder in alkalischen Zustand versetzt (realkalisiert) Zusatzlich kann die Betonoberflache zur dauerhaften Erhaltung der Realkalisierung mit einer Versiegelung versehen werdenThe purpose of the CH realizing process is to comprehend the above mentioned realizing processes observed in nature and to restore the alkaline milieu in the already carbonated concrete and in the reinforcement area Mittel electrochemically supported wet / dry cycles, the behavior in nature is reproduced in a time-lapse process and the carbonated edge zone area is restored to an alkaline state (realized). In addition, the concrete surface can be provided with a seal in order to permanently maintain the realization
1.1.3 Alkalitätszustand in bestehenden Stahlbetonkonstruktionen1.1.3 State of alkalinity in existing reinforced concrete structures
Der Zementstein im fertig hergestellten Beton enthalt unter Gebrauchsbedingungen je nach Wasserzementwert WZ (Verhältnis von Zugabewasser/Zementgehalt) 10-15Vol% Calciumhydroxid Ca(OH)2 (Gelwasser), entsprechend ca, 30-45 Litern je m3 Beton Bei Karbonatisierungstiefen um 20mm (Karbonatisierung Ca(OH)2 + CO2 — > CaCθ3 + H2O) fehlen dem Beton in der Oberschicht somit etwa 0 5-1 Liter je m2 Oberflache Die Aufgabe des CH-Realkalisierverfahrens besteht dann, diesen Mangel aus dem Reservoir des Kernbetons wieder auszugleichenDepending on the water cement value WZ (ratio of added water / cement content), the cement stone in the finished concrete contains 10-15 vol% calcium hydroxide Ca (OH) 2 (gel water), corresponding to approx. 30-45 liters per m 3 concrete at carbonation depths of 20mm ( Carbonation Ca (OH) 2 + CO2 -> CaCθ3 + H2O) the concrete lacks about 0 5-1 liters per m 2 of surface in the upper layer. The task of the CH realizing process is then to compensate for this deficiency from the core concrete reservoir
1.2 Durchführung des Verfahrens1.2 Execution of the procedure
1.2.1 Verfahrensablauf mit Zyklen1.2.1 Procedure with cycles
Die freie Beweglichkeit des Gelwassers im kristallinen Nadelfilz des Zementsteins ist grundlegend durch Adsorptionskrafte der inneren Baustoffoberflache behindert Die Überwindung dieser Kräfte durch geeignete Dimensionierung des elektrischen Feldes (E-Feld), der Dauer der Verfahrensanwendung und der Anzahl von Verfahrenszyklen mit abwechselnder (zyklischer) Wasser-ZTrockungsbehandlung ist Aufgabe des Verfahrens Die Anwendung von Nass-/Trockenzyklen im Wechsel von elektrochemischen lonentransport- und Luft-Wassertransportphasen fuhrt zur stufenwetsen Alkalitats- Anreicherung in der Betonoberschicht Es wird ein gesteuerter lonentransport erreicht und verhindert, dass ein grosserer Teil der OH Ionen in den ausseren Elektrolyten entweichtThe free mobility of the gel water in the crystalline needle felt of the cement stone is fundamentally hampered by adsorption forces on the inner surface of the building material. Overcoming these forces by suitable dimensioning of the electrical field (E field), the duration of the process application and the number of process cycles with alternating (cyclical) water ZDrying treatment is the task of the process. The use of wet / dry cycles alternating between electrochemical ion transport and air-water transport phases leads to step-wise alkalinity accumulation in the concrete top layer. Controlled ion transport is achieved and prevents a larger part of the OH ions from entering the outside Electrolytes escape
Der Ablauf der Nass-/Trockenzyklen und die Beendigung der Verfahrensanwendung erfolgt nach Massgabe der erfolgten Ladung und wird anhand der durchflossenen Anzahl Coulomb gesteuert Eine permanente Überwachung des E-Feldes ist unerlasslich
Zeichnung 1The sequence of the wet / dry cycles and the termination of the application of the process takes place according to the charge that has been made and is controlled on the basis of the number of coulombs flowed through. Permanent monitoring of the E field is essential Drawing 1
Die Wirksamkeit der dargestellten Leistungskomponenten und ihr Zusammenwirken ist von Bauwerk zu Bauwerk verschieden Daher ist durch diagnostische Voruntersuchun¬ gen zu klären, welche Kapillarporosität (Prüfung nach SIA 162/1), Anordnung und statistische Tiefenverteilung der Bewehrung (Prüfung mit Betondeckungsmessgerät) und der Karbonatisierungsstreubereich (Prüfung mit Phenolphthaleintest) vorliegen.The effectiveness of the performance components shown and their interaction differs from building to building.Therefore, diagnostic preliminary examinations must be carried out to determine which capillary porosity (test according to SIA 162/1), arrangement and statistical depth distribution of the reinforcement (test with a concrete cover measuring device) and the carbonation spreading range ( Test with phenolphthalein test).
1.2.2 Anwendungseinzelheiten und -mechanismen1.2.2 Application details and mechanisms
Bei der Verfahrensanwendung werden Anodenmatten in Form von Flutungskassetten oder gesattigten wasserhaltenden porösen Matten mit eingelegtem elektrisch leitendem Gewebe in flachenabhängig unterschiedlicher Grosse an der Betonoberfläche befestigt und Anschlüsse zur Bewehrung als Kathode hergestellt. Zur Verringerung des Zeit¬ bedarfs für die Realkahsierung werden dem Wasser in der Anodenmatte leitfähigkeits- verbessernde Stoffe zugegeben (z B Kaliumkarbonat) Das elektrische Feld (E-Feld) wird aufgebaut mit Gleichstrom-Treibspannungen von 10-50Volt, bei einer Stromstärke von objektabhangig 3-5 A/m2 Betonflache (ca. 2 A/m2 Bewehrung). Die E-Felder sind den Bauwerksgegebenheiten und Erfordernissen der Betonoberflache unter Beachtung der Bauwerksintegπtat anzupassenIn the application of the method, anode mats in the form of flooding cassettes or saturated, water-holding porous mats with inserted electrically conductive tissue in different sizes depending on the flat are attached to the concrete surface and connections for reinforcement are made as cathodes. To reduce the time required for realization, substances that improve conductivity are added to the water in the anode mat (for example potassium carbonate). The electric field (E field) is built up with DC driving voltages of 10-50 volts, with a current of 3 depending on the object -5 A / m 2 concrete surface (approx. 2 A / m 2 reinforcement). The E fields are to be adapted to the building conditions and requirements of the concrete surface, taking into account the building integration
Die Anordnung der Massnahmen am Bauwerk, die Funktionsablaufe und weitere Angaben zu den ablaufenden Vorgangen und Mechanismen sind in Zeichnung 2 ersichtlichThe arrangement of the measures on the building, the functional sequences and further information on the processes and mechanisms involved can be seen in drawing 2
Zeichnung 2Drawing 2
Beim ablaufenden Realkahsiervorgang im E-Feld sind zwei verschiedene Mechanismen zu unterscheiden Durch lonenmigration wandern OH Ionen (Hydroxyl-Ionen) aus dem alkalischen Kernbeton des Kathodenbereichs (Bewehrung) in Richtung Betonoberflache Zum anderen wird die Umgebung der Bewehrungsstahle im karbonatisierten Bereich durch elektrochemischen Stoffumsatz alkalisch angereichert und repassiviert In der Wassertransportphase werden OH-Ionen huckepackartig gegen die Oberfläche transportiert Dieser Transport endet am Wasserdampffilter, der mit der Trocknungs-
behandlung wenige mm unter der Betonoberflache hergestellt wird Hier werden die OH- lonen zurückgehalten, wodurch bei zunehmender Konzentration der Aufbau einer Alkalitatszone erfolgtThere are two different mechanisms to differentiate between the real-life process that takes place in the E-field. Through ion migration, OH ions (hydroxyl ions) migrate from the alkaline core concrete of the cathode area (reinforcement) towards the concrete surface and repassivated In the water transport phase, OH ions are transported piggyback against the surface. This transport ends at the water vapor filter, which is connected to the drying treatment is produced a few mm below the surface of the concrete. The OH ions are retained here, which causes an alkalinity zone to build up as the concentration increases
Der Wirkungsnachweis der Realkalisierung erfolgt durch Kontrolle der neuen Alkalitat in der Betonoberschicht in 5mm-Schichten und Vergleich mit dem Status vor Durchfuhrung des Verfahrens In der Regel wird eine mindestens 100%ιge Wiederherstellung der Alkalitat angestrebtThe proof of effectiveness of the realcalization is carried out by checking the new alkalinity in the concrete top layer in 5mm layers and comparing it with the status before carrying out the process. As a rule, the aim is to restore the alkalinity at least 100%
1.3 Beschreibung der Zeichnungen 1.3.1 Zeichnung 1, Zyklendarstellung1.3 Description of the drawings 1.3.1 Drawing 1, cycle representation
Angabe der Zyklenfolgen im zeitlichen Ablauf der VerfahrensdurchfuhrungSpecification of the cycle sequences in the course of the procedure
EinzelzyklusSingle cycle
- Aufsattigung über 95-97Vol%, Dauer ist Objektabhang ig zu bestimmen- Saturation over 95-97 vol%, duration is to be determined depending on the object
- Einschalten des E-Feldes mit lonentransport - do -- Switch on the E-field with ion transport - do -
- Luft-/Wasserdampfphase - do -- Air / water vapor phase - do -
1.3.2 Zeichnung 2, Funktionsdarstellung1.3.2 Drawing 2, functional representation
Die Zeichnung zeigt die Betonrandzone einer Wandfassade mit Bewehrung und karbonatisierter Betonoberschicht Es werden die Anordnung des E-Feldes mit Anodenmatte, Gleichrichter und Bewehrungsanschluss sowie die dabei ablaufenden lonenwanderungen mit Repassivierung der Bewehrungsoberflache und Reaktionen dargestellt und die ablaufenden Mechanismen angegeben
The drawing shows the concrete edge zone of a wall facade with reinforcement and carbonated concrete top layer. The arrangement of the E-field with anode mat, rectifier and reinforcement connection as well as the ion migration taking place with repassivation of the reinforcement surface and reactions are shown and the running mechanisms are given
Claims
2.Patentansprüche2. Patent claims
2.1 Oberbegriff2.1 generic term
Erhaltung von Betonbauwerken mittels elektrochemischer Verfahren. Realkalisierung karbonatisierter Betonoberschichten und Repassivierung von Bewehrungsstählen.Preservation of concrete structures using electrochemical processes. Realization of carbonated concrete top layers and re-passivation of reinforcing steel.
2.2 Kennzeichnender Teil2.2 Characteristic part
Verfahren zur Realkalisierung karbonatisierter Betonoberschichten und Repassivierung von Bewehrungsstählen, dadurch gekennzeichnet, dass zwischen der Bewehrung und einer im elektrolytischen Medium aufgelegten elektrisch leitenden Gewebematte als Anode ein elektrisches Feld zur elektrochemischen Aktivierung von OH" Ionen im alkalischen Betonbereich sowie zu deren elektrokinetischem Transport in die karbonatisierte Betonoberschicht bzw. Anreicherung am Bewehrungsstahl aufgebaut wird, zyklisch abgelöst durch einen für die Überführung des Wassers in Wasserdampf auf der Betonoberfiäche aufgebauten Luftstrom mit resultierender Bremsung dieser Ionen unterhalb der Wasserdampffront, derart, dass die karbonatisierte Betonoberschicht unter Anreicherung von OH' Ionen wieder in einen alkalischen Zustand mit pH-Wert über 10-11 versetzt und die korrosionsgefährdete Bewehrung innerhalb der Oberschicht mit einem neuen vor Korrosion schutzenden alkalischen Mantel versehen wird.Process for realizing carbonated concrete top layers and re-passivating reinforcing steel, characterized in that between the reinforcement and an electrically conductive fabric mat placed in the electrolytic medium as an anode, an electric field for the electrochemical activation of OH " ions in the alkaline concrete area and for their electrokinetic transport into the carbonated concrete top layer or reinforcement is built up on the reinforcing steel, cyclically replaced by an air flow built up for the conversion of the water into water vapor on the concrete surface with resulting braking of these ions below the water vapor front, in such a way that the carbonated concrete top layer returns to an alkaline state with the enrichment of OH ' ions with a pH value above 10-11 and the reinforcement at risk of corrosion within the top layer is provided with a new, alkaline jacket that protects against corrosion.
Anspruch 1Claim 1
Das Verfahren ist charakterisiert durch das Nutzen von Erkenntnissen aus einem in der Natur beobachteten Realkalisierungsphänomen und Nachstellen dieses Phänomens mittels zyklischer Sattigungs- und Austrocknungsphasen Anspruch 2The method is characterized by the use of knowledge from a realcalization phenomenon observed in nature and the simulation of this phenomenon by means of cyclical saturation and drying phases Claim 2
Das Verfahren ist in Übereinstimmung mit Anspruch 1 charakterisiert durch das Anlegen eines elektrischen Feldes, eine bereits bekannte Methode mit der Bewehrung im alkalischen Betonbereich als ein Element und eine auf die Betonoberfläche im elektrolytischen Medium aufgelegte Gewebematte als externe Elektrode, hier angewendet auf Betonbauwerke, deren Bewehrungsanordnung ein Produzieren, Lösen und Transportieren von OH" Ionen zulässt.The method is characterized in accordance with claim 1 by the application of an electric field, a previously known method with reinforcement in the alkaline concrete area as an element and a fabric mat placed on the concrete surface in the electrolytic medium as an external electrode, here applied to concrete structures, their reinforcement arrangement permits the production, dissolution and transport of OH " ions.
Anspruch 3Claim 3
Das Verfahren ist in Übereinstimmung mit Anspruch 1 und 2 charakterisiert durch den im elektrischen Feld ausgelösten elektrokinetischen lonentransport bis in den karbonatisierten Betonbereich und Abbremsen der OH' Ionen durch gesteuerte Wasserdampfphasen als Massnahme gegen das Austreten und Entweichen ins elektrolytische Medium.The method is characterized in accordance with claims 1 and 2 by the electrokinetic ion transport triggered in the electric field to the carbonated concrete area and braking of the OH ' ions by controlled water vapor phases as a measure against the leakage and escape into the electrolytic medium.
2.3 Unterscheidung2.3 Differentiation
Der Anspruch unterscheidet sich vom Bekannten wie folgtThe claim differs from the known as follows
Die durch das CH-Verfahren im elektrischen Feld aktivierte betoneigene Alkalitat aus dem Calciumhydroxid des alkalischen Zementsteins wird unter Einsatz von Trocken- /Nasszyklen in der Betonoberschicht so stark konzentriert, dass die durch Karbonatisterung verloren gegangene Alkalitat wieder ersetzt wird The concrete's own alkalinity from the calcium hydroxide of the alkaline cement block activated by the CH process in the electric field is so strongly concentrated in the concrete top layer using dry / wet cycles that the alkalinity lost due to carbonate mastering is replaced again
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH125996A CH692297A5 (en) | 1996-05-19 | 1996-05-19 | Calcium hydroxide-Realkalisierungsverfahren. |
| CH1259/96 | 1996-05-19 | ||
| PCT/CH1997/000171 WO1997044295A1 (en) | 1996-05-19 | 1997-04-29 | Calcium hydroxide re-alkalization method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP0839123A1 true EP0839123A1 (en) | 1998-05-06 |
Family
ID=4206208
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP97919236A Withdrawn EP0839123A1 (en) | 1996-05-19 | 1997-04-29 | Calcium hydroxide re-alkalization method |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0839123A1 (en) |
| CH (1) | CH692297A5 (en) |
| WO (1) | WO1997044295A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104849326B (en) * | 2015-04-16 | 2017-12-26 | 同济大学 | A kind of concrete reinforcement erosion condition judgement method |
| CN112142363B (en) * | 2020-10-10 | 2021-12-28 | 杭州瑞鼎建材有限公司 | Automatic shrinkage compensation efflorescence resistant concrete |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5015351A (en) * | 1989-04-04 | 1991-05-14 | Miller John B | Method for electrochemical treatment of porous building materials, particularly for drying and re-alkalization |
| NO880840L (en) * | 1988-02-26 | 1989-08-28 | Jan Saelensminde | PREVENTION FOR CONCRETE TREATMENT. |
-
1996
- 1996-05-19 CH CH125996A patent/CH692297A5/en not_active IP Right Cessation
-
1997
- 1997-04-29 EP EP97919236A patent/EP0839123A1/en not_active Withdrawn
- 1997-04-29 WO PCT/CH1997/000171 patent/WO1997044295A1/en not_active Application Discontinuation
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| Title |
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| See references of WO9744295A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CH692297A5 (en) | 2002-04-30 |
| WO1997044295A1 (en) | 1997-11-27 |
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