Abstract:
The installation and use of embedded sacrificial anodes to protect reinforced concrete may be improved. In one example a cavity [2] is formed in the concrete [3] and a puttylike backfill [4] is placed in the cavity and a compact discrete anode comprising a sacrificial metal element [1] is inserted into the backfill and a space is provided into which the backfill may move when subjected to a pressure arising from the formation of voluminous sacrificial metal corrosion products and a high current is passed from the anode to the steel in the concrete to arrest steel corrosion and activate the anode in the backfill. The space may be provided by venting the backfill to space outside the cavity through an opening [5] or by including a void space within the backfill [6] or a void space within the cavity [7].
Abstract:
Cathodic protection of a structure including a steel member at least partly buried in a covering layer, such as steel rebar in a concrete structure, is provided by embedding sacrificial anodes into the concrete layer at spaced positions over the layer and connecting the anodes to the rebar. The anode body is formed, by pressing together finely divided powder, flakes or fibers of a sacrificial anode material such as zinc to define a porous body having pores therein. The sacrificial anode material of the anode member is directly in contact with the covering material by being buried or inserted as a tight fit into a drilled hole so that any expansion forces therefrom would be applied to the concrete with the potential of causing cracking. The pores are arranged however such that corrosion products from corrosion of the anode body are received into the pores sufficiently to prevent expansion of the anode body to an extent which would cause cracking of the covering material.
Abstract:
Sacrificial anode assemblies have the advantage that they can provide galvanic protection to steel in concrete and do not require long term maintenance of a DC power supply. However sacrificial anode assemblies often loose adhesion to the concrete surface. This invention discloses the use of a sacrificial anode (4) and a backfill (3) and a tape (5) and an adhesive to protect steel (8) in concrete. The backfill is preferably placed in a shallow cavity (1) in the concrete surface (2) and the sacrificial anode is inserted into the backfill. The cavity is covered with a tape that extends over the adjacent concrete surfaces on opposite sides of the sacrificial anode and backfill and the tape is attached to the concrete surface with the adhesive. The tape and the adhesive holds the anode in place and prevents a weathering environment from damaging the backfill.
Abstract:
Disclosed is a method for the cathodic protection (KKS) of the reinforcements of ferroconcrete edifices against corrosion. According to said method, a) one side of the structural joints of the concrete supporting elements is sealed, b) the KKS anodes are introduced into the structural joints, c) an ionically conductive gel is introduced into the joints that are closed on one side, and d) the structural joints are optionally sealed as a whole. Surprisingly, the required electrical conductivity can be reliably ensured during the entire application period with the aid of the ionically conductive gel, which is a prerequisite for effectively and reliably protecting the steel reinforcements of concrete structures against corrosion.
Abstract:
An existing concrete structure is restored by embedding sacrificial anodes into the concrete layer at spaced positions over the layer and connecting the anodes to the reinforcing members to provide a cathodic protection against corrosion. Each anode is inserted into a drilled hole in the layer of sufficient depth to expose the reinforcement. A steel pin passes through a bore in the cylindrical anode and is attached to the reinforcement by arc welding or by impact so as to hold the anode rigidly within the hole. The hole is filled by a settable filler material. In order to maintain effective current conduction from the anode to the reinforcement through the filler over an extended period to maintain the required protection, there is added a material to hold the pH in a preferred range of the order of 12 to 14 and a deliquescent material to absorb moisture into the filler.
Abstract:
A cathodic protection polymeric compound is disclosed. The compound has flowable material to serve as a binder, carbonaceous conductive media dispersed in the flowable material, sacrificial metal particles also dispersed in the flowable material. The carbonaceous conductive media serve as a carbon-based electron transfer agent and are in the form of particles, platelets, fibers, tubes, or combinations thereof. A galvanic circuit is formed by the metal particles serving as anodes, a metal substrate to be protected serving as the cathode, and the conductive media serving as the electron transfer agent. The flowable material can also include an ionically conductive or an inherently conductive polymer to further enhance the galvanic circuit.
Abstract:
There is disclosed a cathodic protection system of reinforced concrete structures with discrete anodes obtained starting from a corrugated planar substrate welded to a longitudinal current collector. The anodes of the invention are particularly suitable for being installed rolled in cylinders, with their axis parallel to the current collectors, positioned inside holes made in the concrete of the structure to be protected.
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.
Abstract:
A bale processor on a wheeled vehicle has a hopper converging inwardly and downwardly to a lower disintegration area at which is located a flail roller rotatable about an axis extending generally along the hopper and including a drive roller or rollers in the hopper for driving rotation of the bale around an axis parallel to the flail roller axis. The processed material is discharged from the disintegration area at the flail roller through an opening in one side wall of the hopper to form a row along that side of the vehicle. A container for particulate material, such as grain, to be added to and mixed with the processed material is carried at the side wall opposite the discharge opening and has an auger tube extending from the container to the hopper at a height below the flail roller and mid way along the side wall so as to introduce the grain into the processed material to mix therewith in the disintegration area.
Abstract:
A method for preventing, inhibiting or reducing the corrosion of metals embedded in cementitious material. The method can comprise manufacturing lithium nitrate. The method can further comprise providing lithium nitrate for addition to a cementitious material at an effetive dosage rate. The dosage rate can be between about 0.01 gram moles per cubic foot of cementitious material and about 100 gram moles per cubic foot of cementitious material, or greater if desired or required. The reduced corrosion rate therefore increases the life expectancy of the structures formable from cementitious material. Some exemplary structures formable from the cementitious material include the following, but not limited thereto, pillars, bridge decks, bridges, road decks, roads, houses, buildings, pilings, railroads, warehouses, piers, parking structures, wharves, and/or any other structures desired and/or required, etc.