Polyurethane composites and methods of preparation are described herein. The polyurethane composites can comprise (a) a polyurethane formed by the reaction of (i) one or more isocyanates selected from the group consisting of diisocyanates, polyisocyanates, and mixtures thereof, and (ii) one or more polyols, (b) a particulate filler having a bulk density of 1 g/cm.sup.3 or greater, (c) optionally a fiber material, and (d) a lightweight filler having a bulk density from 0.01 g/cm.sup.3 to less than 1 g/cm.sup.3. In some examples, the lightweight filler can be selected from expanded perlite, expanded clay, foamed glass, and combinations thereof. Articles such as building materials comprising the polyurethane composites are also disclosed.

The present invention is a manufactured, geometric shaped aggregate intended to replace the gravel or rock aggregate used in a concrete mixture. The geometric shaped aggregate is provided to be solid or hollow. In an embodiment, the hollow aggregate is filled with insulating material or an adhesive solution to fill cracks formed from stress. Electronic components and sensors may be disposed in the hollow aggregate to gather metrics from the solution. In another embodiment, permeable aggregate can allow for moisture mitigation within the concrete structure. The preferred geometric shape of the aggregate is a tetrapod, but other geometric shapes which are known to naturally interweave or intertwine may be used.

An insulating monolithic refractory material having sufficient curing strength and usable time ensured and exhibiting excellent stability at high temperature. The insulating monolithic refractory material comprises a binder and a refractory raw material; a bulk specific gravity thereof is 0.8 to 1.8 when a kneaded mixture of the insulating monolithic refractory material with water is cured at normal temperature for 24 hours and then dried at 110 C. for 24 hours; the binder comprises a calcium aluminate cement including CaO and Al.sub.2O.sub.3 as chemical components and a strontium aluminate cement including SrO and Al.sub.2O.sub.3 as chemical components; and on the basis of 100% by mass as a total mass of the binder and the refractory raw material, a content of the strontium aluminate cement is 2 to 10% by mass, and a content of CaO derived from the calcium aluminate cement is 1 to 12% by mass.

An insulating monolithic refractory material having sufficient curing strength and usable time ensured and exhibiting excellent stability at high temperature. The insulating monolithic refractory material comprises a binder and a refractory raw material; a bulk specific gravity thereof is 0.8 to 1.8 when a kneaded mixture of the insulating monolithic refractory material with water is cured at normal temperature for 24 hours and then dried at 110 C. for 24 hours; the binder comprises a calcium aluminate cement including CaO and Al.sub.2O.sub.3 as chemical components and a strontium aluminate cement including SrO and Al.sub.2O.sub.3 as chemical components; and on the basis of 100% by mass as a total mass of the binder and the refractory raw material, a content of the strontium aluminate cement is 2 to 10% by mass, and a content of CaO derived from the calcium aluminate cement is 1 to 12% by mass.

Adding a small amount of lightweight course aggregate to a normal weight concrete mix to produce a clean, rough top surface so that manual or mechanical roughing of the top surface is not necessary. The lightweight course aggregate will float to the surface, and make a rough surface so that the bond and shear resistance of the interface (cold joint) between previously placed and newly placed concrete will be as strong as a manually roughened joint.

Adding a small amount of lightweight course aggregate to a normal weight concrete mix to produce a clean, rough top surface so that manual or mechanical roughing of the top surface is not necessary. The lightweight course aggregate will float to the surface, and make a rough surface so that the bond and shear resistance of the interface (cold joint) between previously placed and newly placed concrete will be as strong as a manually roughened joint.

A method to mix cement includes preparing a bead suspension comprising beads and preparing a cement slurry separately from the bead suspension, the cement slurry including a cement blend. The method further includes mixing the bead suspension and the cement slurry to create a mixture and pumping the mixture into a well.

A method to mix cement includes preparing a bead suspension comprising beads and preparing a cement slurry separately from the bead suspension, the cement slurry including a cement blend. The method further includes mixing the bead suspension and the cement slurry to create a mixture and pumping the mixture into a well.

A composite binder comprises: one or more Class F fly ash materials, one or more gelation enhancers, and one or more hardening enhancers, wherein each of the one or more Class F fly ash materials comprises 15 wt. % or less calcium oxide, and wherein the composite binder is a Portland cement-free binder for concrete. Also provided are Geopolymer Composite Cellular Concretes (GCCCs) including the composite binder and methods of making these GCCCs.

A composite binder comprises: one or more Class F fly ash materials, one or more gelation enhancers, and one or more hardening enhancers, wherein each of the one or more Class F fly ash materials comprises 15 wt. % or less calcium oxide, and wherein the composite binder is a Portland cement-free binder for concrete. Also provided are Geopolymer Composite Cellular Concretes (GCCCs) including the composite binder and methods of making these GCCCs.