Abstract: A liquid aqueous suspension of polysaccharide, contains a mass concentration of at least one polysaccharide of between 15 and 35% in the form of partially hydrated particles dispersed in an aqueous solution of a strong base salt, excluding ammonium salts, with an ionic strength of between 1.25 mol/L and 15 mol/L, has a pH greater than 9 and contains at least one non-phyllitic crystalline mineral powder, referred to hereafter as filler, which is chemically inert in the aqueous suspension and which has a grain size of between 0.1 and 100 micrometers and an attapulgite in micronized form, the aqueous suspension being stable at least in a temperature range from 5 to 30° C. The suspension is suitable for use as an agent for thickening cementitious compositions.

Abstract: A water retention agent for a cementitious composition, characterized in that it takes the form of a liquid aqueous suspension of at least one polysaccharide at a mass concentration of between 15 and 30% in an aqueous solution of a strong base salt, excluding ammonium salts, with an anionic strength of between 1.25 mol/L and 15 mol/L, having a pH greater than 9 and containing an attapulgite in micronized form and at least one non-phyllitic mineral powder, referred to hereafter as filler, which is chemically inert in the aqueous suspension and which has a grain size of between 0.1 and 100 micrometers, the aqueous suspension being stable at least in a temperature range of between 5° C. and 30° C. The water retention agent is suitable for increasing both the viscosity and the water retention capacity of cementitious compositions without affecting the spreading ability thereof.

Abstract: The self-leveling fluid screed cement composition with limited shrinkage, formed by a mixture of a cement binder, a fluidizing adjuvant, granulates and water, is characterized in that the binder includes 70% to 85% by weight of Portland cement, 7% to 18% by weight of sulfo-aluminous clinker, and 6% to 14% by weight of calcium sulfate, with a calcium sulfate C$/calcium sulfo-aluminate C4A3$ molar ratio of between 5 and 7 and a water/binder ratio by weight of between 0.60 and 0.90. The self-leveling fluid screed that is thus produced has a mechanical resistance to its compression at 24 hours that is at least equal to 1 MPa, shrinkage at 7 days, measured under a relative hygrometry of 50%, less than 500 ?m/m, and an endogenic expansion value that is measured at 7 days, less than 1,000 ?m/m, as well as a very slight lifting of edges.

Abstract: 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, includes the following successive steps: mixing the sediments with a treatment composition including 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 the mixture, leading to a compact mixture having a free water content of less than 20% by weight; then fractionating the compact mixture. The sediment thus treated may be incorporated into concrete or mortar formulas, which then have leachable fractions of less than 1% by weight.

Abstract: The photocatalytic granular mixture for mortar and concrete includes a photocatalyst in the form of at least two granular classes with different B.E.T. specific surfaces. It has a photocatalytic activity greater than that of a monodisperse photocatalyst with a single range of B.E.T. specific surface, and thus permits, in association with a conventional hydraulic binder, to obtain construction and repair materials whose aptitude for self cleaning, for the reduction of odors, and for the depollution of ambient air, is considerably improved.

Abstract: The photocatalytic granular mixture for mortar and concrete includes a photocatalyst in the form of at least two granular classes with different B.E.T. specific surfaces. It has a photocatalytic activity greater than that of a monodisperse photocatalyst with a single range of B.E.T. specific surface, and thus permits, in association with a conventional hydraulic binder, to obtain construction and repair materials whose aptitude for self cleaning, for the reduction of odors, and for the depollution of ambient air, is considerably improved.

Abstract: A cement composition for liquid casting, based on a binder comprising Portland cement and additives comprising at least a fluidizer and a combination of a thickening agent acting by steric exclusion and a gelling thickening agent. The composition can also include a surface active agent to regulate the quantity of entrained air. Mixed with water and an aggregate, it permits obtaining, in a single casting, a self-leveling casting of a high thickness (equal to at least 6 cm) and of low density (about 1.6 to 1.9).

Abstract: A cement composition for liquid casting, based on a binder comprising Portland cement and additives comprising at least a fluidizer and a combination of a thickening agent acting by steric exclusion and a gelling thickening agent. The composition can also include a surface active agent to regulate the quantity of entrained air. Mixed with water and an aggregate, it permits obtaining, in a single casting, a self-leveling casting of a high thickness (equal to at least 6 cm) and of low density (about 1.6 to 1.9).

Abstract: The lightly colored sulfoaluminous clinker contains: more than 55% by weight of calcium sulfoaluminate phase (C4A3S), more than 10% by weight of belite phase (C2S), less than 10% by weight of anhydrite (C{overscore (S)}), and contains practically no ferrite phase, nor a gehlenite phase (C2AS), nor free lime. It is prepared by a process of roasting carried out at temperatures comprised between about 1250° C. and 1350° C. It can be used for a wide range of applications by combining it with a source of calcium sulfate and/or Portland cement, to obtain binders having specific properties (color, setup time, mechanical strength, expansion or contraction . . . ).

Abstract: The surface deactivating composition for concrete or mortar comprising a retardant, water and if desired a rheology modifying agent of the HASE type (emulsion, soluble in alkali, of a polymer with hydrophobic modification), characterized in that the retardant is a carboxylic acid and in that the concentration of HASE is greater than or equal to 0.5% by weight. The process of application consists in applying this deactivating composition in proportions of the order of 0.25+0.05 liter per square meter of the surface, then washing with water this surface after a predetermined period.

Abstract: Waste is rendered inert, by cladding the waste in a cement base hydraulic binder including sulfoaluminate cement comprised by at least 30% by weight of the phase 3CaO.3Al2O3.CaSO4(C4A3S). The hydraulic binder can be either essentially constituted by sulfoaluminate cement, or instead comprise one or several zeolites. A pre-mix is provided for practicing the process, containing at least one zeolite and at least 15% of sulfoaluminate cement, comprised of at least 30% of the phase 3CaO.3Al2O3.CaSO4(C4A3{overscore (S)}). This pre-mix is preferably used for cladding residues of the incineration of household waste.

Abstract: A cement-based product is characterized by constituting a cement and filler mixture into which is incorporated a combination of a cationic additive and an anionic additive.

Abstract: A cement milling agent characterized in that it is composed essentially of sugar-syrup derivatives prepared by oxidizing and hydrogenating said sugar syrups.

Abstract: An apparatus for distributing pneumatically conveyed solid pulverulent material over an annular area of large diameter comprises an enclosure defining an annular chamber having a substantially vertical axis, a closed upper end and a lower end, an upper portion adjacent the closed upper end and a lower portion adjacent the lower end. A section defined by a plane extending perpendicularly to the axis has a constant area in the upper portion and an area decreasing progressively towards the lower end in the lower portion. An annular outlet opening or a series of annularly arranged outlet openings is defined by the lower end, and an inlet conduit for a flow of gaseous fluid for pneumatically conveying the solid pulverulent material into the chamber is connected to the upper chamber portion so that the gaseous fluid flow penetrates the chamber in an approximately radial direction.

Abstract: A method and apparatus for automatically measuring the grain fineness, the gypsum content and the limestone content of a cement sample.A first fraction of the sample is loaded by a vibrating hopper into a crucible resting on an automatic scale. This crucible is handled sequentially by tongs on two revolving arms carried on slidable vertical shafts. The circular paths of the arms intersect at a point just above the scale. Motions of the arms and of the tongs are controlled by a programming unit. The weighed sample is poured into a sieve and the weight of oversize grains is automatically related to the sample weight.Gypsum is measured by heating a second fraction of the sample at 1000.degree. C. plus in an oxygen stream, Fe powder being added from a fixed hopper. The crucible is raised into an induction furnace. Released SO.sub.2 is bubbled in a titration cell to which potassium iodate is gradually added by a burette giving an automatic read-out of the SO.sub.3 (gypsum) titration.

Abstract: The hot air generator according to the present invention comprises a vertical cylindrical enclosure whose walls are covered on the inside with refractory brick, the heating burner being placed at the top of the enclosure and the hot air exhaust orifice being situated at the base thereof, and in which the source of air by which it is fed is divided into three distinct flows: a first flow constituting the combustion air from the burner; a second flow constituting a first current of dilution air cylindrically surrounding the flame; a third flow constituting a second current of dilution air insufflated at the base of the enclosure so that the enclosure comprises three temperature zones: a first temperature zone which is that of the flame and is on the order of 1,800.degree.; a second temperature zone downstream of the flame and on the order of 900.degree.; a third temperature zone which is that of the second dilution current mixes with the flux of hot air which is comprised between 850.degree. and 300.degree..

Abstract: A device is disclosed for continuously making samples to be analyzed by known instruments such as an X-ray spectrometer. The device consists of means for depositing a crude composition and associated vitrifying agent together in a crucible in accordance with a predetermined ratio by weight. The crucible is heated to melt its contents into an homogenous liquid mixture which is cooled to form a solid beadlet to be analyzed. The beadlet is conveyed to the analyzing instrument. A computer measures the respective weights of the components of the crucible contained composition and non-conforming weight measurements result in the crucible being discarded and replaced by another.