A method for the preparation of industrial-scale concrete installations with improved compression strength, curling, cracking and cracking characteristics, the method comprising the addition of nanosilica particulate, and more preferably, colloidal amorphous silica, having specific size and surface area characteristics to a concrete mix after water has been added to the mix and the mix has been agitated.

A macro-cement and associated methods useful for preparing pastes, mortars, concretes and other cement-based materials having high workability, high density, and high strength are disclosed. A method of producing a macro-cement includes cement, supplemental cementitious materials (SCM's), including siliceous submicron-sized particles and nano-sized particles, and polymers in the form of liquid or dry chemical admixtures for concrete. The cement mixture may be used for making ultra-high performance concrete (UHPC).

Functionalized polyacrylate polymer compositions for treating clay or clay bearing aggregates compositions are disclosed. Also disclosed are methods for preparing the functionalized polyacrylate polymer compositions, admixtures containing such polymers and methods for the mitigation of clays in cementitious and aggregate compositions using these polymers.

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.

Geopolymer cement slurries, cured geopolymer cements, and methods of making cured geopolymer cement and methods of using geopolymer cement slurries are provided. The geopolymer cement slurry comprises cement precursor material, Saudi Arabian volcanic ash, and an aqueous solution. The Saudi Arabian volcanic ash comprises SO.sub.3, CaO, SiO.sub.2, Al.sub.2O.sub.3, Fe.sub.2O.sub.3, MgO, and K.sub.2O.

A method for designing a cement composition may include: providing a target compressive strength and a target composition density; selecting at least one cementitious material from a plurality of cementitious materials; calculating a required amount of water to produce a cement composition with the target composition density, the cement composition comprising the water and the at least one cementitious material; calculating a compressive strength of the cement composition based at least in part on a model of compressive strength; comparing the calculated compressive strength to the target compressive strength; and preparing the cement composition with the calculated compressive strength.

A nanozeolite modified green concrete contains alkali-activated natural pozzolan. Natural pozzolan is a green and sustainable material, potentially useful in green concrete, e.g., to curb greenhouse gas emissions associated with ordinary Portland cement production. Nanozeolite (NZ) is present as an additive to the green concrete, e.g., at 3 to 5 wt. %, of natural pozzolan to improve strength development and microstructural properties, resulting in superior strength and denser microstructure compared to a green concrete without nanozeolite.

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.

An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

A nanozeolite modified green concrete contains alkali-activated natural pozzolan. Natural pozzolan is a green and sustainable material, potentially useful in green concrete, e.g., to curb greenhouse gas emissions associated with ordinary Portland cement production. Nanozeolite (NZ) is present as an additive to the green concrete, e.g., at 3 to 5 wt. %, of natural pozzolan to improve strength development and microstructural properties, resulting in superior strength and denser microstructure compared to a green concrete without nanozeolite.