Alumina-modified colloidal silica nanoparticles mitigate Alkali Silica Reaction (ASR) in cementitious compositions. Additives containing the nanoparticles are used in methods of reducing ASR in concrete and to form cementitious compositions. Cementitious products, such as concrete, made by these methods are described herein.

The present invention relates in part to an alkali-silica reaction mitigation admixture comprising an organic or inorganic salt that provides an aluminum, calcium, magnesium, or iron cation. The present invention also relates to a method of mitigating the alkali-silica reaction in a concrete product. The invention is further related to kits comprising the alkali-silica mitigation admixture and an instruction booklet.

Chemical test methods for evaluating the alkali-silica reactivity (ASR) of an aggregate or an aggregate within a particular concrete job mix design by exposing the aggregate to a simplified system with the same or simulated long-term pore solution conditions is provided. ASR is a chemical reaction occurring between alkaline hydroxides within cement paste and certain types of amorphous silica found in mineral aggregates. Causing an accumulation of internal pressure within concrete structures due to the formation of a hygroscopic gel through the absorption of water, ASR leads to expansion and cracking of concrete. The present test method determines the reactivity index (RI) of a given aggregate, or an aggregate as it is to be used in a proposed concrete job mix design by determining the average concentrations of calcium, aluminum, and silicon across multiple tested samples, wherein the RI is the ratio of the concentrations of silicon to that of aluminum and calcium combined.

The present invention is directed to a reinforced building block made of autoclaved aerated concrete (AAC) comprising rebars formed essentially from A) at least one fibrous carrier and B) and a hardened composition formed from B1) at least one epoxy compound and B2) at least one diamine and/or polyamine in a stoichiometric ratio of the epoxy compound B1) to the diamine and/or polyamine component B2) of 0.8:1 to 2:1, as matrix material, and C) optionally further auxiliaries and additives and to methods of production thereof

Some embodiments of the present invention comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, hydraulic cement, and water; and allowing the settable composition to set. Other embodiments comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, calcium hydroxide (lime), and water; and allowing the settable composition to set. Other embodiments comprise a settable composition comprising: remediated coal ash, hydraulic cement, calcium hydroxide, natural pozzolan and water; and allowing the composition to set. Other embodiments comprise a settable composition comprising remediated coal ash and any combination of hydraulic cement, calcium hydroxide, slag, fly ash, and natural or other pozzolan.

A method for reducing or avoiding an alkali-aggregate reaction in a cured concrete. The method includes providing a curable concrete mixture which includes alkali-sensitive aggregates (A), at least one organosilicon compound (B) and/or at least one siloxane (B2). Mass hydrophobization of the curable concrete mixture is achieved by way of adding at least one organosilicon compound (B) to the curable concrete mixture prior to its curing thereby reducing or avoiding an alkali-aggregate reaction in the cured concrete.

A manufacturing method includes: (1) incorporating at least one soluble, calcium, magnesium, or other divalent cation-containing additive into a concrete mixture including aggregates prone to alkali-silica reaction; and (2) curing the concrete mixture to form a concrete product.

Some embodiments of the present invention comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, hydraulic cement, and water; and allowing the settable composition to set. Other embodiments comprise a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising remediated coal ash, calcium hydroxide (lime), and water; and allowing the settable composition to set. Other embodiments comprise a settable composition comprising: remediated coal ash, hydraulic cement, calcium hydroxide, natural pozzolan and water; and allowing the composition to set. Other embodiments comprise a settable composition comprising remediated coal ash and any combination of hydraulic cement, calcium hydroxide, slag, fly ash, and natural or other pozzolan.

A water-based mixture of multi compounds for adding to fresh concrete to protect the concrete against moisture and moisture-associated problems. A hygroscopic and hydrophilic behavior of its crystallization system within a concrete matrix minimizes moisture transmission through capillaries and connected voids. As a result, the mixture may reduce moisture related problems, such as damage caused by repeated freeze and thaw cycles and chloride ion penetration as from deicing salts, as well as alkali-silica reactions, and other problems.

A water-based mixture of multi compounds for adding to fresh concrete to protect the concrete against moisture and moisture-associated problems. A hygroscopic and hydrophilic behavior of its crystallization system within a concrete matrix minimizes moisture transmission through capillaries and connected voids. As a result, the mixture may reduce moisture related problems, such as damage caused by repeated freeze and thaw cycles and chloride ion penetration as from deicing salts, as well as alkali-silica reactions, and other problems.