Corrosion mitigating cement compositions and methods for their preparation are provided. The cement compositions are derived from self-cementing pozzolans and chemical accelerators, retarders, mechanical strength modifiers and corrosion inhibitors. The corrosion inhibitors include boron compounds such as boric acid. Concretes prepared using the cement compositions possess low conductivity and a conductivity which further decreases with aging.

It has been unexpectedly discovered that the addition of a natural or other pozzolan to non-spec coal ash significantly improves the properties of the non-spec coal ash to the extent it can be certified under ASTM C618 and AASHTO 295, as either a Class F or Class C coal ash. The natural pozzolan may be a volcanic ejecta, such as pumice or perlite. Other pozzolans may also be used for this beneficiation process. Many pozzolans are experimentally tested and may be used to beneficiate non-spec coal ash into certifiable Class F coal ash. Additionally, this disclosure provides a method of converting a Class C coal ash to a more valuable Class F coal ash. This discovery will extend diminishing Class F coal ash supplies and turn non-spec coal ash waste streams into valuable, certified coal ash pozzolan which will protect and enhance concrete, mortars and grouts.

An additive formulation for reduction or prevention of microbially induced corrosion in concrete, cementitious material (such as mortar or grout), or a combination thereof. The additive formulation comprises a Quat Silane and a fungicide, wherein the ratio of the Quat Silane to the fungicide in the formulation is in a range of about 10:1 to about 1:10, preferably in a range of about 5:1 to about 1:5.

An additive formulation for reduction or prevention of microbially induced corrosion in concrete, cementitious material (such as mortar or grout), or a combination thereof. The additive formulation comprises a Quat Silane and a fungicide, wherein the ratio of the Quat Silane to the fungicide in the formulation is in a range of about 10:1 to about 1:10, preferably in a range of about 5:1 to about 1:5.

An additive formulation for reduction or prevention of microbially induced corrosion in concrete, cementitious material (such as mortar or grout), or a combination thereof. The additive formulation comprises a Quat Silane and a fungicide, wherein the ratio of the Quat Silane to the fungicide in the formulation is in a range of about 10:1 to about 1:10, preferably in a range of about 5:1 to about 1:5.

According to some embodiments, a curable mixture configured to set in the presence of water, wherein the mixture comprises magnesium oxide, a primary cementitious component and at least one accelerant. A proportion by weight of the primary cementitious component is 80% to 120% of a proportion of magnesium oxide by weight.

Cementitious compositions comprising a hydraulic cementitious material, a compound selected from the group consisting of a polyhydroxy aromatic compound, a polycarboxylic acid-containing compound or a salt thereof, ascorbic acid or a salt thereof, or a combination thereof, and a particulate material or a water soluble silicate-containing material that interacts with the compound are described herein. The polyhydroxy aromatic compound can be a water soluble compound having from two to thirty hydroxyl groups. The particulate material can exhibit a particle size distribution, wherein at least about 90% by weight of the particles have a diameter of less than 2 mm. Suitable particulate materials include nanoparticles and microparticles. The cementitious compositions can be used to form building materials. The cementitious compositions are especially suited for inhibiting corrosion of reinforcing steel bars embedded in concrete mixtures. Methods of making and using the cementitious composition are also disclosed.

A system and a method are provided for inhibiting pyrrhotite-caused damage to concrete structures. The system includes at least one concrete structure, a quantity of migratory corrosion-inhibiting solution, a quantity of concrete reinforcing solution, and a water sealing substance. The concrete structure can be any structure where the concrete aggregate contains pyrrhotite. The quantity of migratory corrosion-inhibiting solution is applied to the concrete structure to prevent further oxidation of pyrrhotite within the concrete structure. The quantity of concrete reinforcing solution is applied to the concrete structure to lower the porosity of the concrete structure and strengthen the overall integrity of the concrete structure. The water sealing substance is applied to the concrete structure to repel water from the concrete structure preventing any further chemical reactions with the pyrrhotite.

A formulation including a material that is in a wet-state in which the material is an uncured concrete, an uncured cementitious material, or a combination thereof, a Quat Silane that cures on and/or within the material, a fungicide, and a defoamer.

An additive formulation for reduction or prevention of microbially induced corrosion in concrete, cementitious material (such as mortar or grout), or a combination thereof. The additive formulation comprises a Quat Silane and a fungicide, wherein the ratio of the Quat Silane to the fungicide in the formulation is in a range of about 10:1 to about 1:10, preferably in a range of about 5:1 to about 1:5.