A method for forming cement-based cementitious material includes: pouring a cement paste into a mold; applying an electrical current to the cement paste to perform an electro-osmotic reaction; and transferring the reacted cement paste into a water tank for curing, thereby obtaining a functionally graded cement-based cementitious material. A pair of electrodes is placed in the mold and connected to an external power source. The compressive strength of the functionally graded cement-based cementitious material in the middle is lower than that at either of both ends.

Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120° C. and positive 300° C.; ECMCs that need to be able to contain a flame of 1900° C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid “ceramic microdomains” (CMDs); the CMDs are connected to one another by a dense network of “elastic microelements” (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.

An anti-blast concrete and a method of fabricating an anti-blast structure member using such anti-blast concrete are disclosed. The composition of the anti-blast concrete according to the invention includes, in parts by weight, 1.0 part by weight of cement, 1.0 to 2.5 parts by weight of fine aggregates, 1.0 to 2.5 parts by weight of coarse aggregates, and a plurality of reinforcing fibers. The weight ratio of the reinforcing fibers to the cement ranges from 0.5% to 3%. The plurality of reinforcing fibers are a plurality of carbon fibers or a plurality of aramid fibers. A test body, made of the anti-blast concrete of the invention, has an average number of times of repeated impacts at an impact energy of 49.0 Joules equal to or larger than 41 times at 28 days of age.

Disclosed herein are methods and compositions for cementing. An example method may comprise providing a cement composition. The cement composition may comprise a composite cementitious material comprising a micronized particulate solid and a monophase amorphous hydraulic binder. The micronized particulate solid may have a mean particle size of about 500 microns or less. The cement composition may further comprise water. The method may further comprise introducing the cement composition into a subterranean formation; and allowing the cement composition to set.

Described herein is a polyion complex, including x mol of polycations and y mol of polyanions, x and y being integers from the range of 1 to 100 and x being ≤y or x being ≥y. Also described herein is a method for producing a polyion complex, an aqueous solution of a polyion complex obtained using the method, and the aqueous solution of a polyion complex itself. Also described herein is a method of using a polyion complex to modify the surface of polymer fibers and/or carbon fibers and a method for modifying the surface of polymer fibers and/or carbon fibers using an aqueous solution of the polyion complex. Also described herein are surface-modified polymer fibers and/or carbon fibers obtained using the method, the surface-modified polymer fibers and/or carbon fibers themselves, methods of use thereof to produce fiber-modified construction materials, and a fiber-modified construction material including same.

Systems and methods are disclosed for producing a shaped cementitious article comprising mixing foamed glass aggregate particles, Portland cement, and water, placing the mixture into a mold, applying vibration and/or pressure to the mold, removing the mold, and then curing the molded concrete article. The shaped cementitious article may be a concrete block (e.g., a solid block, a hollow block, a flue, a curb, or a paver). The concrete block may be a relatively lightweight formed concrete block defining a hollow interior portion (e.g., “cinder block” shaped).

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods makes use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

Methods of preparing engineered cementitious composite precursors include carbonating a fly ash comprising >about 25% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the fly ash to a first gas stream comprising carbon dioxide to form a carbonated fly ash. A steel slag is also carbonated that comprises>about 40% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the steel slag to a second gas stream comprising carbon dioxide to form a carbonated steel slag. The carbonated fly ash and the carbonated steel slag are suitable for use as engineered cementitious composite precursors in a bendable engineered cementitious composite composition that further comprises Portland cement, a polymeric fiber, and a superplasticizer.

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.

The present invention relates to a polymer composition for forming fibers for reinforcement of cement-based composites, polymer fibers made from the composition and methods of making the polymer fibers. The polymer composition comprises an olefin polymer and a bonding agent comprising vinyl alcohol based polymer, a pozzolanic material or a combination thereof.