The invention comprises a cementitious material comprising a natural pozzolan selected from hyaloclastite, sideromelane or tachylite, wherein the natural pozzolan has a volume-based mean particle size of less than or equal to 40 μm. The cementitious material also comprising an aqueous alkaline activating solution suitable for forming a geopolymer. A method making a cementitious material is also disclosed.

The invention comprises a cementitious material comprising a natural pozzolan selected from hyaloclastite, sideromelane or tachylite, wherein the natural pozzolan has a volume-based mean particle size of less than or equal to 40 μm. The cementitious material also comprising an aqueous alkaline activating solution suitable for forming a geopolymer. A method making a cementitious material is also disclosed.

Disclosed is a preparation method of a polycarboxylate water reducer having a regular sequence structure. The preparation method of the present invention comprises: performing Michael addition on polyethylene glycol ether acrylate macromonomer A and amino-containing carboxylic acid B for 5-12 hours, then cooling to 0° C., dropwise adding acryloyl chloride slowly and evenly, and further reacting for 12 hours at room temperature to obtain carboxyl-containing polyether macromonomer C; mixing the carboxyl-containing polyether macromonomer C, a small molecular RAFT reagent, an initiator, and water adequately; and holding the polymerization mass concentration at 30%-60% and heating to 60-80° C. in the atmosphere of N2 to react for 2-5 hours to obtain the polycarboxylate water reducer having a regular sequence structure.

This invention discloses a double-liquid grouting slurry, its technology and application for super large diameter underwater shield engineering under high water pressure condition. The materials of slurry I are: 35-45 parts of cement clinker; 15-25 parts of slag; 24-35 parts of fly ash; 15-25 parts of steel slag; 5-15 parts of bentonite; 4-10 parts of limestone tailing; 0.3-2.0 parts of water reducing agent; 0.5-2.5 parts of cellulose. The materials of slurry II are: 0.2-3.8 parts of short-cut fiber; 96-99 parts of sodium silicate solution; 0.8-4.8 parts of viscous polymers. This invention generates the double-liquid slurry preparation process including crushing-screening-milling-group mixing-grouped mixing at different speeds, the volume ratio of slurry I and II is 1:1-10:1 during grouting, and the slurry is injected into the shield void through the six-point position technology at the shield tail and 3+2+1 segment splicing synchronous grouting techniques.

The present invention is the production method of ready injection material which aims to develop natural hydraulic lime in nano size by using a single raw material.

The present invention is the production method of ready injection material which aims to develop natural hydraulic lime in nano size by using a single raw material.

A composition may be suitable for flowable refractory materials and include calcium aluminate cement, a filler, a plasticizer in the form of a copolymer comprising polyether side chains, and a retarder having at least one acid. An article may include such a composition.

A composition may be suitable for flowable refractory materials and include calcium aluminate cement, a filler, a plasticizer in the form of a copolymer comprising polyether side chains, and a retarder having at least one acid. An article may include such a composition.

A sacrificial concrete for a core catcher and a preparation method thereof are provided. The sacrificial concrete includes raw materials in parts by weight as follows: cement, 575˜625 parts; a quartz sand, 1200˜1300 parts; a hematite ore, 700˜800 parts; water, 200˜220 parts; a water reducing agent, 7˜10 parts; and strontium oxide, 0˜10 parts. The process of the preparation method is simple, and the sacrificial concrete with excellent performances of fluidity, strength and high-temperature resistance can be prepared by the known mixing technology. The sacrificial concrete can reduce releasing of radioactive substances .sup.89Sr and .sup.90Sr, so as to improve safety of nuclear power plants in case of a severe accident. Moreover, the sacrificial concrete can be used not only in a core catcher of current third generation nuclear power plant, but also in a core catcher of future fourth generation nuclear power plant, and has widespread engineering application value.

A sacrificial concrete for a core catcher and a preparation method thereof are provided. The sacrificial concrete includes raw materials in parts by weight as follows: cement, 575˜625 parts; a quartz sand, 1200˜1300 parts; a hematite ore, 700˜800 parts; water, 200˜220 parts; a water reducing agent, 7˜10 parts; and strontium oxide, 0˜10 parts. The process of the preparation method is simple, and the sacrificial concrete with excellent performances of fluidity, strength and high-temperature resistance can be prepared by the known mixing technology. The sacrificial concrete can reduce releasing of radioactive substances .sup.89Sr and .sup.90Sr, so as to improve safety of nuclear power plants in case of a severe accident. Moreover, the sacrificial concrete can be used not only in a core catcher of current third generation nuclear power plant, but also in a core catcher of future fourth generation nuclear power plant, and has widespread engineering application value.