The present invention relates to a method of treating marine or river dredging sediments, especially harbour zone sediments, whose free water content is between 40% and 80% by weight, for the purpose of obtaining a solid material which is easy to handle, characterized in that it comprises the following successive steps: - mixing said sediments with a treatment compo-sition comprising a sulphoaluminate binder and at least one other component selected from a sulphate source and a catalyst of the hydration reactions of the sulphoaluminate binder, - a step of setting of said mixture, leading to a compact mixture having a free water content of less than 20% by weight, - then fractionating said compact mixture. The sediment thus treated may be incorporat-ed into concrete or mortar formulas, which then have leachable fractions of less than 1% by weight.

Method of treating marine sediments and use of the resulting solid product in mortars or concretes

A method for producing a clinker for cement, comprising grinding a raw flour comprising, especially, Al 2 O 3 , Fe 2 O 3 and SO 3 in contents such that the formula for calculating SO 3 content of=0.261×Al 2 O 3 −0.638×Fe 2 O 3 +k, where 2.5<k<3.5, then by sintering flour in an overn wherein the temperature is between 1250° C. and 1350° C. and oxygen content is between 2.5% and 10% by volume.

Method for producing a clinker for hydraulic cement with low co2 emission and high resistance

The invention discloses a concrete compaction anti-cracking agent which comprises 20.0-60.0% of light calcined magnesia, 10.0-30.0% of calcium oxide-calcium sulfoaluminate double-expansion source expanded clinker, 5.0-15.0% of gypsum and 20.0-50.0% of a fine powder material of which the specific surface area is greater than 300m /kg, wherein the sum of the contents of all components is 100% based on the total mass of the concrete compaction anti-cracking agent. The concrete compaction anti-cracking agent can be used in concrete to effectively inhibit shrinkage of the concrete and improve the compactness and the durability of the concrete.

Concrete compaction anti-cracking agent

PROBLEM TO BE SOLVED: To provide a floor slab reinforcing method for preventing adhesion of a fiber reinforced concrete layer and an asphalt mixture layer from being lowered even when construction of repairing an existing asphalt mixture layer is performed, and providing flexural strength and flexural toughness equal to or more than those of a conventional steel fiber reinforced concrete layer.SOLUTION: The floor slab reinforcing method includes a fiber reinforced concrete layer forming step and an asphalt mixture layer forming step. In the fiber reinforced concrete layer forming step, concrete containing cement, aggregates, organic fibers and water is coated on a floor slab 11 to form a fiber reinforced concrete layer 12. In the asphalt mixture layer forming step, a waterproof layer and an asphalt mixture layer 13 are formed on the fiber reinforced concrete layer 12. In the fiber reinforced concrete layer forming step, fiber assemblies of organic fibers are used for the organic fibers.

Floor slab reinforcing method

PROBLEM TO BE SOLVED: To provide a concrete composition providing concrete good in filling property to a steel bar rear face without generating rougenenness on a road having a slope while having ultra rapid hardening property, excellent in processability, capable of thin film processing and having high toughness.SOLUTION: There is provided a fiber reinforced concrete composition containing cement of 100 pts.wt., a coarse aggregate of 120 to 210 pts.wt., a fine aggregate having absolute dry specific gravity of 2.3 or more of 105 to 280 pts.wt. and an organic fiber having fiber length of 18 to 30 mm of 3.2 to 7.0 pts.wt. and having fine aggregate percentage of 44.0 to 57.0%.SELECTED DRAWING: None

Ultra rapid hardening type high toughness fiber-reinforced concrete

PROBLEM TO BE SOLVED: To improve not only quality by enhancing the durability of a floor slab but also reducing vibration and noise generated by construction, while a thickness is smaller than that in a conventional floor slab upper-surface thickness increasing construction method. SOLUTION: The surface of an existing floor slab 1 used for a bridge and a superhighway is ground, polished and cleaned, and soft concrete 2 of a slump of 10 cm or larger is placed for covering the surface of the ground, polished and cleaned floor slab 1, and the soft concrete 2 is compacted and integrated into the existing floor slab 1 by imparting high frequency vibration to a screed plate 12 of a concrete finishing device 10. The soft concrete 2 includes water, a hydraulic setting composition, an aggregate, an expansive admixture and fiber. The hydraulic setting composition uses a material for revealing a compressive strength of 10 N/mm 2 or higher in 2-3 hours after construction as a hardening speed of the soft concrete 2. COPYRIGHT: (C)2009,JPO&INPIT

Floor slab reinforcing method and concrete finishing device used therefor

Disclosed is a hardened concrete structure which is produced by blending a water-curable composition with an expansive mixed material and then hardening the resulting mixture, wherein the water-curable composition comprises 100 parts by weight of a calcium sulfoaluminate composition comprising 3 to 60% by mass of calcium sulfoaluminate and 1 to 40% by mass of gypsum anhydride and 0.1 to 3.0 pats by weight of lithium carbonate having a specific surface area of 1000 to 4000 cm2/g, and the expansive mixed material comprises at least one composition selected from the group consisting of a 3CaO·SiO2-2CaO·SiO2-CaO-gap substance composition, a 3CaO·SiO2-CaO-gap substance composition, a 2CaO·SiO2-CaO-gap substance composition and a CaO-gap substance composition, and further comprises a clinker composition having a CaO content of 50 to 92% by mass and gypsum. The hardened concrete structure can develop its strength rapidly, shows a high strength, has reduced shrinkage strain which is caused by self-shrinkage, drying shrinkage or the like, and is reduced in cracking which is caused by shrinkage strain or the like.

Hardened concrete structure and concrete composition

PROBLEM TO BE SOLVED: To provide a concrete setting object which has high strength while being accompanied by rapid development of strength, can reduce the shrinkage distortion due to self-shrinkage, drying shrinkage, etc., and can prevent the occurrence of a crack etc., due to shrinkage distortion. SOLUTION: The concrete setting object is prepared by setting a formulated material including an expandable admixture including a clinker composition containing a hydraulic composition including 0.1 to 3.0 parts by mass lithium carbonate of 1,000 to 4,000 cm 2 /g specific surface area, based on 100 parts by mass, calcium sulfoaluminate composition including 3 to 60 mass% calcium sulfoaluminate and 1 to 40 mass% anhydrous gypsum, and a composition including one or two or more kinds selected from the group consisting of a 3CaO-SiO 2 -2CaO-SiO 2 -CaO-interstitial material-based composition, 3CaO-SiO 2 -CaO-interstitial material-based composition, 2CaO-SiO 2 -CaO-interstitial material-based composition, and CaO-interstitial material-based composition, and containing 50 to 92 mass% CaO of the total mass of these compositions, and gypsum, metallic fibers or organic fibers. COPYRIGHT: (C)2008,JPO&INPIT

Hitoshi Fujita

Papers

Floor slab reinforcing method and concrete finishing device used therefor

Hardened concrete structure and concrete composition

Concrete setting object and concrete composition