Abstract: The corrosion-preventing additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete. The corrosion-preventing additive is a solution with an organic solvent, the solute being either gallic acid (3,4,5-trihydroxybenzoic acid), at least one ester of gallic acid, or combinations thereof. The weight-to-volume concentration of the solute to the organic solvent may be between 1% and 10% w/v. Reinforced concrete may be made using the corrosion-preventing additive by mixing the corrosion-preventing additive with a conventional concrete mixture (i.e., a mixture of an aggregate, water, and cement), with at least one steel rebar being embedded in the mixture, similar to conventional steel rebar reinforced concrete. The concentration of the corrosion-preventing additive with respect to the cement of the mixture may be between 0.0125 wt % and 1.0 wt %.

Abstract: The coupled borate/silicate salts-based additive for mortar or concrete controls chloride induced pitting and uniform corrosion of steel rebars embedded in the mortar or concrete with no detrimental effect on compressive strength of mortar/concrete. The silicate compounds may include one or more of the salts of sodium, potassium, lithium, calcium, magnesium, manganese, iron, zinc, aluminum and other transition and valve metals. The borate compounds may include one or more of the salts of alkali and alkaline earth metals, transition, non-transition and valve metals such as sodium, potassium, lithium, calcium, magnesium, manganese, iron, zinc, aluminum and others. The combination of the borate and silicate salts as an additive has been shown to impart high protection to steel rebar surfaces against corrosion, and particularly chloride induced pitting corrosion. The additives are equally effective for mortar as well as concrete.

Abstract: The corrosion-preventing additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete. The corrosion-preventing additive is a solution with an organic solvent, the solute being either gallic acid (3,4,5-trihydroxybenzoic acid), at least one ester of gallic acid, or combinations thereof. The weight-to-volume concentration of the solute to the organic solvent may be between 1% and 10% w/v. Reinforced concrete may be made using the corrosion-preventing additive by mixing the corrosion-preventing additive with a conventional concrete mixture (i.e., a mixture of an aggregate, water, and cement), with at least one steel rebar being embedded in the mixture, similar to conventional steel rebar reinforced concrete. The concentration of the corrosion-preventing additive with respect to the cement of the mixture may be between 0.0125 wt % and 1.0 wt %.

Abstract: The method of curing reinforced concrete uses a liquid membrane-forming curing compound for the curing of reinforced concrete, but without fully coating the reinforced concrete with the curing compound, thus allowing for oxygen permeation through the reinforced concrete to effect passive layer formation on steel rebar embedded in the reinforced concrete. Prior to curing, a mask is applied to at least one surface of a slab of reinforced concrete, such that the mask covers about 10% of the surface area of the at least one surface. The at least one surface of the slab of reinforced concrete is then coated with a liquid membrane-forming curing compound. The liquid membrane-forming curing compound is allowed to dry, thus forming a curing compound layer on the at least one surface of the slab of reinforced concrete. The mask is then removed to form at least one uncoated region.

Abstract: The corrosion-preventing additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete. The corrosion-preventing additive is a solution with an organic solvent, the solute being either gallic acid (3,4.5-trihydroxybenzoic acid), at least one ester of gallic acid, or combinations thereof. The weight-to-volume concentration of the solute to the organic solvent may be between 1% and 10% w/v. Reinforced concrete may be made using the corrosion-preventing additive by mixing the corrosion-preventing additive with a conventional concrete mixture (i.e., a mixture of an aggregate, water, and cement), with at least one steel rebar being embedded in the mixture, similar to conventional steel rebar reinforced concrete. The concentration of the corrosion-preventing additive with respect to the cement of the mixture may be between 0.0125 wt% and 1.0 wt%.

Abstract: The additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete, improving the workability of the cast concrete, and reducing water absorption/permeability in the cast concrete. The reinforced concrete may be a conventional reinforced concrete, such as that formed from a mixture of water, an aggregate and cement, having at least one steel rebar embedded in the mixture. The additive is added to the mixture prior to curing and casting. The additive may for example, have a concentration with respect to the cement of between 0.25 wt % and 1.0 wt %. The additive includes a triazole and a non-ionic surfactant including a poly oxy ethoxylated reaction product of sorbitan and a fatty acid. The triazole and the non-ionic surfactant are dissolved in the solvent.

Abstract: The corrosion-preventing additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete. The corrosion-preventing additive is powdered scoria, including concentrations of about 45 wt % SiO2, 14 wt % Fe2O3, and 15.5 wt % Al2O3, with the remainder being standard components found in volcanic rock. The average particle size of the powdered scoria is 45 microns or less. Reinforced concrete treated with the corrosion-preventing additive includes a mixture of an aggregate, water, and cement (such as Portland cement), along with at least one steel rebar embedded in the mixture, and the powdered scoria.

Abstract: The method of ascertaining fully grown passive film formation on steel rebar embedded in concrete utilizes electrochemical impedance spectroscopy (EIS) to determine, in situ, the degree of passive film formation on steel rebar embedded in concrete. A length of steel rebar and a counter electrode are both embedded in a concrete slab. A reservoir is supported on an external face of the concrete slab and filled with an electrolytic solution. A reference electrode is then positioned in the electrolytic solution, and the length of steel rebar, the counter electrode and the reference electrode are electrically connected an EIS test instrument to perform electrochemical impedance spectroscopy. The quality of passive film formation on the length of steel rebar is determined based on comparison of the electrochemical impedance spectroscopy results with known passive film formation data.

Abstract: The method of ascertaining fully grown passive film formation on steel rebar embedded in concrete utilizes electrochemical impedance spectroscopy (EIS) to determine, in situ, the degree of passive film formation on steel rebar embedded in concrete. A length of steel rebar and a counter electrode are both embedded in a concrete slab. A reservoir is supported on an external face of the concrete slab and filled with an electrolytic solution. A reference electrode is then positioned in the electrolytic solution, and the length of steel rebar, the counter electrode and the reference electrode are electrically connected an EIS test instrument to perform electrochemical impedance spectroscopy. The quality of passive film formation on the length of steel rebar is determined based on comparison of the electrochemical impedance spectroscopy results with known passive film formation data.

Abstract: A system for determining longitudinal moments in a one-way joist floor comprising a supporting girder includes at least one computer configured to determine boundaries of at least one equivalent frame, determine a longitudinal moment within a column-beam portion of the at least one equivalent frame based at least in part on a vertical rigidity of the supporting girder, the column-beam portion having at least one column, and determine a longitudinal moment within a lateral section of the at least one equivalent frame based on the longitudinal moment within the column-beam portion, and based at least in part on the vertical rigidity of the supporting girder, the lateral section being lateral to the column-beam portion.

Abstract: A raw batch composition for concrete or concrete wherein the raw batch composition comprises Portland cement of about 15 wgt. % to about 45 wgt. % and dune sand preferably red dune sand is present in an amount of about 40 wgt. %. The dune sand has a particle size of less than or equal to 45 microns. The composition also includes limestone powder ranging from about 15 wgt. % to 45 wgt. % with particle sizes less than or equal to 45 microns to form a base material. To this base material suitable amounts of fine aggregate, coarse aggregate, water and superplasticizer are added. A method for producing a cast concrete product having a compressive strength of between 62 MPa and 90 MPa is disclosed. The method comprises a step of providing Portland cement, dune sand and limestone powder.

Abstract: A raw batch composition for concrete or concrete wherein the raw batch composition comprises Portland cement of about 15 wgt. % to about 45 wgt. % and dune sand preferably red dune sand is present in an amount of about 40 wgt. %. The dune sand has a particle size of less than or equal to 45 microns. The composition also includes limestone powder ranging from about 15 wgt. % to 45 wgt. % with particle sizes less than or equal to 45 microns to form a base material. To this base material suitable amounts of fine aggregate, coarse aggregate, water and superplasticizer are added. A method for producing a cast concrete product having a compressive strength of between 62 MPa and 90 MPa is disclosed. The method comprises a step of providing Portland cement, dune sand and limestone powder.

Abstract: A system for determining longitudinal moments in a one-way joist floor comprising a supporting girder includes at least one computer configured to determine boundaries of at least one equivalent frame, determine a longitudinal moment within a column-beam portion of the at least one equivalent frame based at least in part on a vertical rigidity of the supporting girder, the column-beam portion having at least one column, and determine a longitudinal moment within a lateral section of the at least one equivalent frame based on the longitudinal moment within the column-beam portion, and based at least in part on the vertical rigidity of the supporting girder, the lateral section being lateral to the column-beam portion.