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.

A radiation shield unit, which shields against neutron rays, X-rays, and γ-rays, contains 10 vol % or more and 90 vol % or less of gadolinium.

A variety of fluid loss control compositions and methods are provided for controlling fluid loss in a cementing operation. As described herein, polyelectrolyte complex nanoparticles and fluid loss control compositions containing polyelectrolyte complex nanoparticles can be effective for fluid loss control in a variety of cementing operations. Methods of making and methods of using the electrolyte complex nanoparticles and fluid loss control compositions containing polyelectrolyte complex nanoparticles are also provided. The polyelectrolyte complex nanoparticles can include a polycation polymer such as a branched chain polyethylenimine, and a polyanion polymer such as polyacrylic acid or poly(vinylsulfonic) acid. The polyelectrolyte complex nanoparticles can contain additional additives such as metal ions or fluid loss additives such as a cellulose polymer.

A precast concrete molded body is provided, which is a cured product of a concrete composition. The concrete composition comprises: a microcapsule; cement; and at least one type of aggregate. The microcapsule is provided with a core-shell structure having i) a core made of a water repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensation products, and branched siloxane resins, and ii) a shell made of a silicon-based network polymer containing silica units. The concrete composition contains 0.01 to less than 0.5 parts by weight of microcapsules per 100 parts by weight of cement. Thereby, a precast concrete molded body can be provided, having high strength, as well as at least one of the following properties: air content stability, substance penetration prevention, and freeze-thaw resistance.

An additive injection system can be a part of a cementitious slurry mixing and dispensing assembly. The additive injection system can be used to inject an additive into an auxiliary slurry discharge conduit carrying a secondary flow of cementitious slurry produced in the assembly such that the secondary slurry stream is different from a main slurry stream discharged from a main slurry discharge conduit.

The present invention is directed to processes for making cementitious construction material, in particular magnesium oxychloride (MOC) cementitious construction material (e.g., MOC boards). The processes relate to one or more operations of the overall material production process, including material storage and handling, mixing of materials, curing to form magnesium oxychloride cement, board handling, and/or packaging. Various processes of the present invention involve process control strategies and/or algorithms to provide improved processes for producing construction material. In particular, the processes of the present invention provide improvements in board properties as detailed below (e.g., racking strength), speed of board production, economics of board production, reduction in complexity of manufacture, improvements in consistency of board manufacture, and improvements in quality control.

The embodiments described herein generally relate to methods and chemical compositions for use with wellbore treatment processes. In one embodiment, a composition is provided comprising a cementitious material, a drilling fluid, or combinations thereof, and an additive composition comprising one or more components selected from the group of an aqueous insoluble lignin, a coke fine, a random tetracopolymer having the formula styrene-butadiene-acrylic-fumaric acid, a polyvinyl acetate, a surfactant composition, and combinations thereof.

Disclosed herein is a warm mix asphalt additive comprising (a) a wax; (b) a phosphoric ester; and (c) a fatty amine. Preferably component (a) is a fatty amide wax and component (b) is a C16-C18 alkyl phosphoric ester. Also disclosed is a warm mix asphalt binder composition comprising asphalt and a warm mix asphalt additive, and methods for its preparation thereof. Additionally disclosed is a warm mix asphalt composition comprising a warm mix asphalt binder and aggregate, and methods for its preparation thereof.

A method for manufacturing an engineered stone, the method including: providing a mixture comprising at least a stone or stone like material and a binder; compacting the mixture; curing the binder; and further comprising printing a printed pattern on at least a top surface of the engineered stone.

Disclosed is a concrete product incorporating rubber aggregate produced by casting under pressure. The concrete product may optionally be cast at 6.9-27.7 MPa for periods of, for example, 24 hours. In one embodiment the rubber aggregate may comprise coarse and/or fine rubber aggregate to replace natural sources of coarse and fine aggregate. Casting under pressure was found to generally improve the performance characteristics of the concrete when compared to corresponding concrete cast without pressure.