Abstract:
The sacrificial anode cathodic protection for reinforcing steel in concrete is accomplished and enhanced by mixture control of cementitious material covering zinc or zinc alloy anode. At least 4% lithium hydroxide by weight of the cementitious material is required to prevent the passivation of the zinc anodes after use for many years. The zinc anodes covered by the cementitious material with sand size number about 30 to 60 of US standard sieve provide better uniform current output. Combination of minimum lithium hydroxide and sand size control in the cementitious material will improve the anodes performance and prevent them from passivation.
Abstract:
The present invention relates to a method of installing an unbonded flexible pipe with a bore for transportation of fluid wherein the unbonded flexible pipe comprises an outer sheath, an inner sealing sheath inside the outer polymer sheath, an annulus between said outer sheath and said inner sealing sheath and at least one metallic armor layer comprising iron located in said annulus, wherein the method comprises filling at least a part of the annulus with a corrosion promoting liquid before or after installing the unbonded flexible pipe between a first installation and a second installation.
Abstract:
An article of manufacture comprising iron oxide, silicon oxide, calcium oxide, magnesium oxide, and aluminum oxide; wherein the article of manufacture is capable of functioning as an anode is disclosed. An article of manufacture comprising a by-product from a steel process comprising oxide fines, mill scale, slurry, or bag house dust or a combination thereof; wherein the article of manufacture is capable of functioning as an anode is also disclosed. An article of manufacture comprising iron oxide, silicon oxide, calcium oxide, magnesium oxide, and aluminum oxide; wherein the article of manufacture is an anode is also disclosed. An article of manufacture comprising a by-product from a steel process comprising oxide fines, mill scale, slurry, or bag house dust or a combination thereof; wherein the article of manufacture is an anode is also disclosed. Also disclosed are methods of using and methods of making the article of manufacture.
Abstract:
Humectants are applied to cathodic protection systems which utilize a conductive paint anode or thermally-sprayed zinc or zinc alloy anodes applied to the surface of reinforced concrete structures. The humectants are deliquescent or hygroscopic organic or inorganic salts, hydrophilic polymers or colloids, or organic liquid desiccants. The humectants are positioned at or near the interface between the anodes and the concrete in a free flowing form and increase the moisture content at the interface. This increases the ability of the anode to deliver cathodic protection current to steel embedded in the concrete. The humectants may be applied to the concrete surface prior to application of the anode, or may be applied subsequent to installation of the anode. In an embodiment of the invention, the humectant is a lithium salt. The initiation of current delivery in the system results in the injection of lithium ions into the concrete which mitigates what is known as an alkali-silica reaction in the concrete.
Abstract:
Reinforcement in concrete (1) is cathodically protected by galvanically connecting a sacrificial anode (3), such as a zinc or zinc alloy anode, to the reinforcement (2), and contacting the anode with an electrolyte solution having a pH which is maintained sufficiently high for corrosion of the anode to occur, and for passive film formation on the anode to be avoided. The pH of the electrolyte is preferably at least 0.2 units, more preferably from 0.5 units to more than 1.0 units above the pH value at which passivity of the anode would occur. The electrolyte may be for example sodium hydroxide or potassium hydroxide but is preferably lithium hydroxide which also acts as an alkali-silica reaction inhibitor.
Abstract:
Es wird ein Verfahren zum Herstellen eines kathodischen Korrosionsschutzes zum Schutz von Bewehrungsstahl (2) in einem Stahlbetonbauwerk (1) angegeben, bei dem der Chlorid-induzierten Korrosion ausgesetzte Stahlbetonbauwerke besonders einfach und dauerhaft vor Korrosion geschützt werden können. Darüber hinaus soll der kathodische Korrosionsschutz besonders schnell und sowohl bei Neubauten als auch im Rahmen einer Sanierung/Nachrüstung realisiert werden können. Dazu wird auf den Stahlbeton ein Textilbeton (8) appliziert, wobei der Textilbeton (8) ein Carbongewebe (10) und einen Mörtel umfasst, wobei zwischen einer Kathode und einer Anode eine elektrische Dauerspannung angelegt wird und wobei der Bewehrungsstahl (2) als Kathode und das Carbongewebe (10) als Anode verwendet wird.
Abstract:
Die Erfindung betrifft ein hydraulisches Bindemittel, umfassend K, Ca, Alumosilikate, sowie gegebenenfalls Li, Na, und Mg, mit dem Kennzeichen, dass es die folgenden Komponenten umfasst: a) latent hydraulisches Alumosilikatglas mit einem Verhältnis von (CaO+MgO+AI 2 O 3 )/SiO 2 > 1 und b) Alkaliaktivator der Summenformel (I): a(M 2 O) * X(SiO 2 ) * y(H 2 O) wobei M = Li, Na, K, a = 0-4 sowie x = 0-5 und y = 3-20 bedeuten, wobei das Molverhältnis von Ca/Si 0,1 ist. Weiters betrifft sie aus diesem Bindemittel hergestellte Bindemittelmatrizes, Mörtel, Betonkleber und Metallanoden.
Abstract:
Es wird ein Verfahren zum kathodischen Korrosionsschutz (KKS) von Bewehrungen von Stahlbetonbauwerken beschrieben, wobei man a) eine Seite der Konstruktionsfugen der Betonträgerteile abdichtet, b) die KKS-Anoden in die Konstruktionsfugen einbringt, c)in die einseitig verschlossenen Fugen ein ionisch leitfähiges Gel einbringt und d) ggf. die Konstruktionsfugen vollständig abdichtet. Es hat sich hierbei überraschenderweise gezeigt, dass man mit Hilfe des ionisch leitfähigen Gels die notwendige elektrische Leitfähigkeit über die gesamte Anwendungsdauer zuverlässig gewährleisten kann, welches eine Grundvoraussetzung für einen effektiven und zuverlässigen Korrosionsschutz der Stahlbewehrungen von Betonwerken darstellt.
Abstract:
A method of protecting steel in concrete is disclosed. It consists of connecting the steel (6) to a discrete sacrificial anode assembly (7) comprising a base metal (1), a relatively small quantity of catalytic activating agent in contact with the base metal and a substantially inert porous layer (3) that surrounds the base metal and catalytic activating agent. The inert porous layer efficiently maintains a sustainable concentration gradient of the catalytic activating agent between the base metal and the surrounding environment as a result of the electric field across this layer. The preferred porous layer comprises a material that exhibits a net repulsion of negative ions from its pore system and the preferred catalytic activating agent comprises doubly charged sulphate ions as small electric fields maintain very high concentration gradients of these ions resulting in high concentrations at the base metal surface and insignificant concentrations at the assembly periphery.