The present invention relates to calcium-containing, porous, mineral materials having a sulfate content of not more than 1.5% by weight and a biopolymer content in the range of 0.001 to 5.00% by weight, each relative to the total weight of the materials, a method for producing these materials with the aid of biopolymers as stabilizers and the use of biopolymers for producing sulfate-poor calcium-containing, porous, mineral materials.

The present invention relates to methods for the production of fresh cured fiber cement products. More particularly, the present invention provides methods for the production of fresh fiber cement products comprising cured fiber cement waste material, at least comprising the steps of: (a) Providing a cured fiber cement waste powder by comminuting cured fiber cement waste material; (b) Providing an aqueous fiber cement slurry comprising water, cementitious binder, natural or synthetic fibers and said cured fiber cement waste powder; (c) Forming a green fiber cement sheet from said aqueous fiber cement slurry; and (d) Autoclave-curing said green fiber cement sheet thereby providing a fresh fiber cement product.

The present invention relates to methods for the production of fresh cured fiber cement products. More particularly, the present invention provides methods for the production of fresh fiber cement products comprising cured fiber cement waste material, at least comprising the steps of: (a) Providing a cured fiber cement waste powder by comminuting cured fiber cement waste material; (b) Providing an aqueous fiber cement slurry comprising water, cementitious binder, natural or synthetic fibers and said cured fiber cement waste powder; (c) Forming a green fiber cement sheet from said aqueous fiber cement slurry; and (d) Autoclave-curing said green fiber cement sheet thereby providing a fresh fiber cement product.

There is described a high-strength concrete generally having: about 100 parts by weight of cement; about 60 to about 360 parts by weight of fine aggregates; about 90 to about 230 parts by weight of mineral powder having a diameter D50 below 150 .Math.m; about 0.1 to about 25 parts by weight of superplasticizer; and about 20 to about 65 parts by weight of water, the high-strength concrete has a cement content less than about 500 kg/m.sup.3 and having a compressive strength after 28 curing days of about 55 MPa or greater.

The present invention relates to a curable resin composition. More specifically, the present invention relates to a composition comprising methylene malonate functional reactive resin, to its preparation methods, and to the use of the composition in the construction field.

The present invention relates to a curable resin composition. More specifically, the present invention relates to a composition comprising methylene malonate functional reactive resin, to its preparation methods, and to the use of the composition in the construction field.

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.

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.

A synchronous single-liquid grouting slurry, its technology and application for large diameter shield engineering under water-rich, high-pressure and weak soil strata conditions, comprising raw materials: 1050-1200 parts of gold tailing, 420-480 parts of silicate cement clinker, 220-240 parts of fly ash, 45-120 parts of waste clay brick, 65-95 parts of slag, 25-45 parts of limestone tailing, 70-80 parts of steel slag, 30-45 parts of silica fume, 15-22 parts of desulfurized gypsum, and 9-15 parts of quick-setting and early-strength composite additive. The invention controls the d.sub.50, d.sub.85 and d.sub.95 of the material particles as 35-40, 42-48 and 50-55 μm, respectively. Gold tailing with the particle size of 120-600 μm being used as the fine aggregate, their volume fractions are 40-60%. The slurry production technique, comprising crushing-sieving-superfine ball milling-homogenization-particle size classification-variable speed mixing being developed. The shield tail eight-point grouting technique is being developed for filling.

Disclosed are a method for separately preparing light magnesium oxide and calcium oxide by using dolomite and an application thereof in preparation of a calcium-magnesium composite expanding agent. In the method for preparing light magnesium oxide and calcium oxide, based on the difference in decomposition temperature between magnesium carbonate and calcium carbonate during the calcination and decomposition of dolomite and the difference in the weight of the materials after decomposition, the effective separation of magnesium oxide and calcium oxide is realized by a one-step method, thus separately preparing light magnesium oxide and light calcium oxide. The calcium-magnesium composite expanding agent is prepared by using the foregoing light magnesium oxide and calcium oxide. On the one hand, the present invention solves the problem of the limited origin of the light magnesium oxide raw material of the magnesium expanding component in the calcium-magnesium composite expanding agent.