A refractory composition including refractory aggregate, one or more matrix components, and silicate-coated set accelerator particles. The silicate-coated set accelerator particles can include one more of silicate-coated calcium hydroxide, magnesium hydroxide, calcium chloride, calcium carbonate, magnesium carbonate and calcium sulfate. Suitable silicate coatings include sodium silicate, potassium silicate, lithium silicate and mixtures thereof. A method of recovering an aged refractory composition, a settable composition and a method of manufacturing silicate-coated calcium hydroxide particles are also provided.

A cement mixture is disclosed that includes an aqueous mending agent that is disbursed within but isolated from the cement mixture, wherein the aqueous mending agent will form molecular bonds with hardened cement that is formed by the cement mixture when the aqueous mending agent is permitted to flow within the hardened cement.

A cement mixture is disclosed that includes an aqueous mending agent that is disbursed within but isolated from the cement mixture, wherein the aqueous mending agent will form molecular bonds with hardened cement that is formed by the cement mixture when the aqueous mending agent is permitted to flow within the hardened cement.

A cement composition is provided. The cement composition comprises: a microcapsule and cement. The microcapsule is provided with a core-shell structure having i) a core containing a water-repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensation products, and branched siloxane resins, and ii) a shell of a silicon-based network polymer containing a silica unit. The microcapsule is included at 0.01 to less than 0.5 parts by weight per 100 parts by weight of the cement. Thus, it is possible to provide a cement composition that can provide a cured product having high strength, as well as excellent air content stability, substance penetration prevention, drying shrinkage, and freeze-thaw resistance.

A cement composition is provided. The cement composition comprises: a microcapsule and cement. The microcapsule is provided with a core-shell structure having i) a core containing a water-repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensation products, and branched siloxane resins, and ii) a shell of a silicon-based network polymer containing a silica unit. The microcapsule is included at 0.01 to less than 0.5 parts by weight per 100 parts by weight of the cement. Thus, it is possible to provide a cement composition that can provide a cured product having high strength, as well as excellent air content stability, substance penetration prevention, drying shrinkage, and freeze-thaw resistance.

A delivery device for concrete admixtures, in the form of a film of watersoluble material, having a concrete admixture incorporated within the film. The film can be attached to a formwork for concrete and has a protective layer, which is removable to allow the water in the concrete to dissolve the film and release the admixture into the concrete. The film contains the required quantity of admixture and is weather-resistant and substantially time-insensitive. The delivery device is used in a process to retard the setting portion of a surface of concrete.

Compositions and a method for making self consolidating grouts containing fly ash, ground granulated blast slag, and lime are described. No polymeric admixtures are utilized, and the 28 day cure strength of the cured gouts exceeds the minimum ASTM standards. The uncured grout exhibits slump flows between 24 and 30″ without visible segregation of the components.

Compositions and a method for making self consolidating grouts containing fly ash, ground granulated blast slag, and lime are described. No polymeric admixtures are utilized, and the 28 day cure strength of the cured gouts exceeds the minimum ASTM standards. The uncured grout exhibits slump flows between 24 and 30″ without visible segregation of the components.

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.

A multi-component inorganic capsule anchoring system can be used for chemical fastening of anchors, bolts, screw anchors, screw bolts, and post-installed reinforcing bars in mineral substrates. The multi-component inorganic capsule anchoring system contains a curable powdery ground-granulated blast-furnace slag-based component A, and an initiator component B in aqueous-phase for initiating the curing process. The powdery ground-granulated blast-furnace slag-based component A contains further silica dust. The component B contains an alkali- or alkaline earth-hydroxide, alkali- or alkaline earth-carbonate, or alkali-or alkaline earth-sulfate component.