The invention relates to a process for preparing silica-coated particles of an inorganic expanding agent, the silica-coated particles and their use. The silica-coated particles show a delayed release of the expanding agent particularly in alkaline medium and at elevated temperatures. They are therefore useful in the oil and construction industry.

The present invention belongs to the field of composite materials, particularly to an underwater non-dispersible quick-setting and rapid-hardening cement-based composite material and the preparation method and application thereof. The material consists of the following raw materials in percentage by weight: 32%-34% of silicate cement, 8.8%-9% of calcium aluminate, 5%-7% of magnesium oxide, 0.5%-2% of sulfur trioxide, 0.2%-0.3% of polycarboxylate high performance water-reducing agent, 0.3%-0.7% of flocculant, 0.05%-0.2% of setting accelerator, 0.05%-0.2% of air-entraining agent, 0.05%-0.3% of rust inhibitor, 26%-31% of fine aggregate, 13%-18% of coarse aggregate, and 8.4%-8.5% of water. The material can be used for rapid repair of cement buildings in water conservancy projects, the repair material can be quickly set and the initial strength can be guaranteed.

A polymer-modified cementitious composition comprising a specific aqueous polymer dispersion and a cementitious material, and such polymer-modified cementitious composition having low ammonia release and providing coating membranes made therefrom with balanced tensile strength and elongation at break.

A composition including: at least one waterbased polyurethane dispersion containing ethylene oxide units; at least one cement; and at least one mineral filler. The composition can be mixed and applied without coagulation of the polyurethane dispersion. Upon curing, it has a high strength and good adhesion properties, with surprisingly low shrinkage and most surprisingly good water impermeability properties. It is particularly suitable for the use as repair mortar, waterproofing mortar or screed mortar.

There is provided a fiber-reinforced brittle matrix composite. The fiber-reinforced brittle matrix composite comprises a brittle matrix material (for example, a cementitious or ceramics material) and a coated fiber embedded in the brittle matrix material, wherein the coated fiber comprises a fiber (for example, polyethylene fiber, glass fiber, silicon carbide fiber, alumina fiber, mullite fiber) and a coating material (for example, carbon nanofibers, carbon nanotubes), which is non-covalently disposed on the fiber. A method for producing the fiber-reinforced brittle matrix composite is also provided. The method comprises providing a fiber, disposing a coating material on the fiber to form a coated fiber, wherein the coating material is non-covalently disposed on the fiber, and embedding the coated fiber in a brittle matrix material to obtain the fiber-reinforced brittle matrix composite.

The present invention is a system for repairing asphalt. The system includes a discrete quantity of an asphalt repair composition located within a container and an induction heater. The composition is a combination of an asphalt binder, aggregate particles, and induction particles. The average diameter of the induction particles ranges from approximately 10% above to approximately 10% below an average diameter of the aggregate particles used in the composition. The induction heater heats the composition within the container by generating a magnetic field that penetrates the container. The magnetic field creates eddy currents in the induction particles. These eddy currents in turn heat the composition. Because the induction particles are distributed throughout the composition, the composition heats rapidly.

A method of sealing propagating cracks in a sensor-laden cement sheath comprising the steps of monitoring an electrical resistivity of the sensor-laden cement sheath to produce a measured value, wherein the sensor-laden cement sheath comprises a conductive sensor, an on-demand expanding agent, and a cement, activating a heat source when the measured value of the electrical resistivity is greater than an activation threshold, increasing a temperature of the sensor-laden cement sheath with the heat source to an activation temperature, wherein the activation temperature is operable to initiate a reaction between the on-demand expanding agent and water, wherein the activation temperature is greater than a formation temperature, reacting the on-demand expanding agent with water to produce a swelled agent, wherein the swelled agent occupies a greater volume than the on-demand expanding agent, and sealing the propagating cracks in the sensor-laden cement sheath with the swelled agent.

The invention involves an exposed aggregate architectural coating to be applied to existing concrete structures. The invention includes a method of preparing and roughening an existing concrete structure surface, mixing the components of the exposed aggregate architectural coating, applying the coating to the existing concrete structure, spreading the coating to a thickness of one-fourth of an inch or thinner, using a trowel, gauge rake, or other method to smoothen the coating, allowing the coating to cure, applying a surface retarder once the exposed aggregate architectural coating has stiffened, allowing the surface retarder to cure for twenty-four hours, and washing the surface with a pressure-washer to remove the surface retarder, then acid-washing the surface to remove residue and create a desired texture. The resulting applied exposed aggregate architectural coating will have an exposed aggregate finish that is durable and suitable for high vehicular and pedestrian traffic areas.

A composition that may include a resin, plastic aggregate, plastic fines, and optionally fly ash. The plastic aggregates and plastic fines may be formed from recycled plastic. The composition may be utilized to repair damaged surfaces, including damages concrete surfaces. The composition may further be used in pre-formed structures. The pre-formed structures may include panels that are assembled to form an upright enclosure, such as a shelter.

A pigmented asphaltic sealant composition and methods of preparing and using the sealant composition which eliminate or reduce a color contrast between the sealant composition and the road, pavement, or other substrate surface to which the sealant composition is applied.