Abstract: Provided is a method for evaluating and utilizing sonnenbrand basalt aggregate, including steps as follows: mixing a basalt aggregate defined as sonnenbrand basalt into an asphalt mixture; carrying out thermal aging experiments at different temperatures and durations to obtain a theoretical trigger time ti for the sonnenbrand phenomenon under a thermal aging temperature Ti; further calculating to obtain a theoretical thermal aging factor AF0 for the sonnenbrand phenomenon; statistically calculating a thermal aging factor AF for an actual construction to evaluate a performance of the basalt aggregate, if AF<AF0, the construction may be carried out normally, if AF?AF0, then shortening the transportation and waiting duration and/or lowering the factory temperature of the asphalt mix so that the thermal aging factor AF<AF0 during actual construction.

Abstract: A cement clinker which can be sintered at 1,300 to 1,400° C. which is lower than the conventional sintering temperature and develops excellent strength characteristics such as mortar compression strength. The cement clinker has a total content of C3A and C4AF calculated by Bogue's formulas of 22 mass % or more, a C3S content calculated by Bogue's formula of 60 mass % or more and an iron modulus (I.M.) of 1.3 or less, preferably 1.0 to 1.3. Since the total content of C3A and C4AF is 22 mass % or more, the cement clinker can be sintered at a low temperature and the reduction of strength when a cement composition is cured can be prevented by reducing the iron modulus of the cement clinker.

Abstract: A shrinkage compensating concrete does not require restraint. The expansive forces developed during hydration compensate for concrete shrinkage, obviating the need for any added internal or external restraint element. Using this new shrinkage compensating concrete, substantially crack-free slabs may be built without using restraining steel bars, fibers, or other separate restraining element. The shrinkage compensating concrete includes a cement that develops internal expansive forces that never exceed the tensile strength of the concrete, such that the internal expansion compensates for the concrete shrinkage. The expansive cement may be an ASTMS, M or S cement, or other expansive cements may also be used.

Abstract: An inorganic board contains, in a solid content ratio, 30 to 70 mass % of hydraulic material, 5 to 15 mass % of reinforcing fiber, and 1 to 30 mass % of wollastonite having a wet volume (after being allowed to stand for 30 minutes) of 15 to 45 ml. Also, a method includes: step of producing a slurry containing hydraulic material, reinforcing fiber, and wollastonite; step of producing a sheet by dehydrating the slurry; and step of pressing and curing the sheet; wherein, in the step of producing a slurry, a composition of the slurry is set so as to contain, in a solid content ratio, 30 to 70 mass % of hydraulic material, 5 to 15 mass % of reinforcing fiber, and 1 to 30 mass % of wollastonite having a wet volume (after being allowed to stand for 30 minutes) of 15 to 45 ml.

Abstract: A cement clinker which can be sintered at 1,300 to 1,400° C. which is lower than the conventional sintering temperature and develops excellent strength characteristics such as mortar compression strength. The cement clinker has a total content of C3A and C4AF calculated by Bogue's formulas of 22 mass % or more, a C35 content calculated by Bogue's formula of 60 mass % or more and an iron modulus (I.M.) of 1.3 or less, preferably 1.0 to 1.3. Since the total content of C3A and C4AF is 22 mass % or more, the cement clinker can be sintered at a low temperature and the reduction of strength when a cement composition is cured can be prevented by reducing the iron modulus of the cement clinker.

Abstract: An aqueous gypsum plaster-cement composition comprises a hydraulic binder consisting of calcined gypsum and hydraulic cement in a weight ratio of from about 4:1 to about 2:1, an aggregate which comprises sand, a foam, a perlite, rice hulls or a mixture thereof, a superplasticizer comprising an air entraining agent, a retarder, and water in an amount of from about 0.4 to about 0.75 parts by weight per part of binder, with the proviso that the gypsum plaster-cement composition contains essentially neither a pozzolana nor lime. The use thereof, a method of constructing buildings using this composition and the buildings obtainable in this way are also described.

Abstract: Embodiments include a method, mixture, and system for increasing a friction coefficient of a surface or increasing or maintaining traction of an object on the surface. In one embodiment, the mixture comprises pulverized lime, fine sand, granite fines, gypsum, and expanded perlite. The mixture may optionally further comprise dye. In an embodiment, the method comprises mixing pulverized lime, fine sand, granite fines, and gypsum with one another to form a first mixture; and mixing expanded perlite with the first mixture to provide a product mixture for increasing the friction coefficient of the surface or increasing or maintaining traction of an object on the surface. In some embodiments, the expanded perlite may be mixed with dye prior to mixing the expanded perlite with the first mixture.

Abstract: A reduced weight, reduced density gypsum panel that includes high expansion vermiculite with fire resistance capabilities that are at least comparable to (if not better than) commercial fire rated gypsum panels with a much greater gypsum content, weight and density.

Abstract: The present disclosure relates to geothermal grout, methods of making geothermal grout, and methods of using geothermal grout. The present disclosure is further directed to an geothermal grout with relative ease of preparation and desirable thermal conductivity while maintaining good sealant properties.

Abstract: A method of making a cementitious composition comprises (a) selecting at least one pozzolanic particulate material; (b) selecting and grinding at least one feldspar material to a fineness of at least 3000 Blaine; (c) mixing calcium oxide or calcium hydroxide with gypsum; (d) mixing the ground feldspar with the lime-gypsum mixture to produce an activator; (e) conditioning the pozzolanic particulate material with an aqueous solution; (f) adding the activator to the conditioned material to produce a slurry; and (g) curing the slurry in a sealed container. The pozzolanic particulate material can be slag, fly ash, or siliceous rock. A cementitious composition of the invention comprises a pozzolanic particulate material, a ground feldspar material, a lime compound and gypsum, and uses readily available materials, as an economic replacement for Portland cement, fly ash or other materials in filling, backfilling and paving, particularly for backfilling or stabilizing mine sites.

Abstract: Flame-retarding additives that may also have insulating properties are disclosed that include at least one carbonate salt, and at least one additional salt, active ingredient or combination thereof. In addition, methods of forming flame-retarding additives are disclosed that include providing at least one carbonate salt, providing at least one additional salt, active ingredient or combination thereof; and combining the at least one carbonate salt along with the at least one additional salt, active ingredient or combination thereof to form the flame-retarding additive. Flame-retarding additives disclosed may also comprise at least one filler material, including sand or white sand. These additives may also be included in paints and a number of processed building materials.

Abstract: The present invention relates to boron-containing compositions. The invention relates to comminuted, heteroge-neousboron-containing compositions which are obtainable by a process which comprises heating to a temperature sufficiently high that calcination occurs but insufficient for the formation of a homogeneous melt a mixture comprising components capable, under the conditions of heating, of forming the oxides B2O3 and SiO2 and optionally Al2O3, Na2O and/or CaO in proportions such that the relative percentages by weight of the said oxides, based on the total weight of said oxides, are as follows: 5 to 35% B2O3; 10 to 65% SiO2; 0 to 35% Al2O3; and up to 20% Na2O and/or up to 50% CaO; with the proviso that the said B2O3 content is not 10 to 18%, when the other contents are as follows: 40 to 65% SiO2, 17 to 32% Al2O3 4 to 9% Na2O, and 0 to 10% CaO, and then comminuting the resulting composition.

Abstract: Methods of preparing improved settable compositions free of Portland cement and methods of using such compositions in subterranean operations are provided. An example of a method of preparing such compositions may comprise providing an unhydrated mixture of raw materials comprising a silica component, an aluminum component, a magnesium component, a sodium component, a calcium component, a ferrous or ferric component, a sulfurous component, and a potassium component, wherein the mixture has been formed without heating any of the components to above about 3000° F.; and adding water to the unhydrated mixture of raw materials to form a settable composition.

Abstract: The present invention relates to a chemically resistant glass composition for the production of reinforcing strands which comprises the following constituents within the limits defined below, expressed in mol %: SiO2 67-72%; ZrO2 5-9.5%, preferably ?7.5%; R2O (R=Na, K and Li) 11-17%; Li2O 0-5.5%; K2O 0-5.5%; Na2O<10%; and CaO 3-9%, the composition furthermore containing less 1% of impurities (Al2O3, Fe2O3, Cr2O3, TiO2, MgO, SrO, BaO and P2O5) and being free of F. It also relates to the glass strands obtained from this composition and to the composites based on an organic or inorganic material containing such strands.

Abstract: Effective use of dispersants in wallboard containing foam results from a method where stucco is mixed with a first dispersant and a first quantity of water to form a gypsum slurry. A soap is blended with a second dispersant and a second quantity of water to make a foam. Subsequently, the foam is combined with the slurry. Choice of different first and second dispersants and their relative amounts allows control of the size distribution of the foam bubbles in the slurry and the resulting voids in the gypsum core. Use of the same dispersant in both the mixer and the foam water provides a boost in efficacy of the dispersant.

Abstract: A composition is disclosed for a mixture to be used in conjunction with water for preparing a slurry that hydrates to form a high strength flooring compound. The mixture includes from about 50% to about 98% by weight calcium sulfate hemihydrate. A three repeating unit polycarboxylate dispersant is included in the mixture in amounts from about 0.2% to about 10% by weight. The repeating units include a polyether repeating unit, an acrylic acid-type repeating unit and a maleic acid-type repeating unit. A modifier that enhances the efficacy of the dispersant is also a component of the mixture. When combined with recommended amounts of water, a slurry is formed that is useful as a flooring composition.

Abstract: A burnt product is produced by burning a raw material containing chromium, in which the fine-grained portion is removed. Even in the burnt product produced from a raw material containing chromium, the chromium (VI) content is reduced.

Abstract: A wall repair compound useful for filling and repairing cracks, holes, and other imperfections in a wall surface includes a conventional filler material, a conventional binder material, and a dust reducing additive which reduces the quantity of airborne dust particles generated when sanding the hardened joint compound. Airborne dust reducing additives include oils, surfactants, solvents, waxes, and other petroleum derivatives. The additive can be added to conventional ready-mixed joint compounds and to setting type joint compounds. A method of reducing the quantity of airborne dust generated when sanding a fully hardened joint compound includes mixing a sufficient quantity of the dust reducing additive with the joint compound prior to when the joint compound has been applied to the wall.

Abstract: A novel cement is alkalescent, capable of solidifying a wide range of soil and applicable to biological environment. The cement composition contains 100 parts by weight of magnesium oxide, 5 to 25% by weight of at least one of silicic acid, alumina and iron oxide, 3 to 35 parts by weight of a phosphate, 2 to 30 parts by weight of gypsum and 0.005 to 7 parts by weight of a hydroxycarboxylic acid or a ketocarboxylic acid.

Abstract: The current invention provides an improved permeable cement composition for formation of downhole sand screens. The improved composition includes an effective amount of a surfactant. Addition of the surfactant to the permeable cement composition yields at least a pumpable slurry with a minimal amount of water or brine solution.

Abstract: A composition and method for treating a surface is described. In one embodiment, the composition comprises about 10% to 90% by weight of cement, about 10% to 90% by weight of plaster, about 0.01% to about 20% by weight of lime, and about 0% to about 30% by weight of perlite. In another embodiment, the composition comprises plaster, cement, perlite, lime, joint compound and water, wherein the plaster, cement, perlite, and lime are in a ratio of about 10-90: 10-90: 0-30: 0.01-20 by weight. In another embodiment, the composition is prepared by a method comprising: (a) providing a first mixture comprising plaster, cement, perlite, and lime; (b) converting the first mixture to a second mixture by a method selected from the group consisting of stirring the first mixture, passing the first mixture through a strainer, and milling the first mixture; and (c) mixing the second mixture with joint compound and water to obtain the composition.

Abstract: The present invention refers to a mixture comprising alpha CaSO4×½ H2O, CaSO4×2 H2O, a combination of a hardening accelerator, a hardening retarder and a setting expansion inhibitor, and optionally a surfactant. The mixture can be used to prepare a die having an extremely high setting expansion.

Abstract: Disclosed is a mold material for metal casting capable of suppressing the deterioration of cast metal. The mold material for metal casting contains hemihydrate gypsum and a heat resistant material, wherein an oxoacid salt of phosphorus, insoluble in water, is contained in the mold material.

Abstract: The present invention refers to a mixture comprising alpha CaSO4×½H2O, CaSO4×2H2O, a combination of a hardening accelerator, a hardening retarder and a setting expansion inhibitor, and optionally a surfactant.

Abstract: The invention concerns silica sol mixture comprising a first silica sol having a broad particle size distribution, the relative standard deviation being at least about 30% by numbers, and a second silica sol having a narrow particle size distribution having a relative standard deviation lower than about 15% by numbers. The invention also concerns a method for preparing a silica sol mixture and use thereof. The invention further concerns a concrete composition comprising a silica sol mixture and a method for preparing such composition.

Abstract: This invention relates to an aqueous suspension including a mixture of at least one aqueous suspension of precipitated silica and of at least one latex, in which the aqueous suspension of precipitated silica has a solids content of between 10 and 40% by weight, has a viscosity lower than 4×10−2 Pa s at a shear of 50 s−2 and, after centrifuging at 7500 revolutions per minute for 30 minutes, produces a supernatant containing more than 50% of the weight of the silica initially in suspension. This suspension can be employed in compositions based on an inorganic binder and in concrete compositions.

Abstract: The present invention provides improved early-enhanced strength cement compositions and methods. The cement compositions can be utilized in surface construction projects as well as in the construction of oil, gas and water wells. The improved cement compositions of this invention are basically comprised of a hydraulic cement, water present in an amount sufficient to form a slurry and hydrophobic silica powder.

Abstract: An aqueous suspension is provided including a mixture of at least one aqueous suspension of precipitated silica and of at least one latex, in which the aqueous suspension of precipitated silica has a solids content of between 10 and 40% by weight, has a viscosity lower than 4×10−2 Pa s at a shear of 50 s−1 and, after centrifuging at 7500 revolutions per minute for 30 minutes, produces a supernatant containing more than 50% of the weight of the silica initially in suspension. This suspension can be employed in compositions based on an inorganic binder and in concrete compositions.

Abstract: This invention relates to an aqueous suspension including a mixture of at least one aqueous suspension of precipitated silica and of at least one latex, in which the said aqueous suspension of precipitated silica has a solids content of between 10 and 40% by weight, has a viscosity lower than 4×10−2 Pa s at a shear of 50 s−1 and, after centrifuging at 7500 revolutions per minute for 30 minutes, produces a supernatant containing more than 50% of the weight of the silica initially in suspension.

Abstract: A method of reducing the curing time of drywall joint compound, and thereby reducing the time required to finish drywall joints or to repair plaster walls, includes adding a predetermined amount of a drying agent to a conventional ready-mixed drywall joint compound. The drying agent preferably comprises at least one compound selected from the group of compounds consisting of plaster of Paris, calcium carbonate, gypsum, crystallized silicon dioxide (quartz), Portland cement, perlite, lime, hydroxy ethyl ether of cellulose, polyvinyl alcohol, starch, wood fiber, potassium naphthalene sulfon, aluminum sulfate, sodium citrate, ammonium tartrate, hydrolyzed protein, monosodium phosphate, sodium naphthalene sulfonate, potassium sulfate and various trace materials, or mixtures thereof A sufficient amount of water is added to the drying agent to facilitate mixing the drying agent with the drywall joint compound to form a joint compound mixture.

Abstract: The present invention is of a cementitious composition containing OPC, calcined gypsum, a source of amorphous silica and a source of amorphous alumina. The ratio of calcium sulfate hemihydrate to OPC is 0.7:1.0 to 1.4:1.0, the ratio of amorphous silica and amorphous alumina to OPC is 0.26:1.0 to 0.4:1.0, and the ratio of amorphous alumina to amorphous silica is 0.3:1.0 to 1.5:1.0. The cementitious composition, by itself and mixed with aggregates, is fast-setting and exhibits good early compressive strength and very high compressive strength after hydration. Despite the high content of calcium sulfate relative to prior art OPC formulations, the cementitious composition according to the present invention is essentially waterproof and exhibits excellent strength characteristics, even after 2 years under water. The use of calcined gypsum in place of alumina cement or even OPC is of great economic advantage, and in addition, provides the cementitious composition with quick-setting characteristics.

Abstract: The present invention relates to improved investment powders for use in making improved investment molds for casting metals, and the use of such molds with vacuum and/or either conventional, convection conduction or microwave heating apparatus, to rapidly eliminate water, wax and residual carbon from the mold cavities at temperatures lower than the casting temperature range of the mold at the time of casting.

Abstract: The invention provides cementitious mixtures, particularly for use as shotcrete binding materials. The resultant shotcrete has characteristics of rapid setting as low as 5 to 10 minutes, high early compressive strength (5 to 25 MPa in two hours curing, 20 to 60 MPa in one day curing), high permanent compressive strength and negligible shrinkage. High aluminous content roasted cement clinkers with gypsum, anhydrite, lime, limestone, bentonite and other additives are used in the mixtures. There are especially suitable for use in shotcrete engineering. The methods of using the improved shotcrete are similar to those of using Portland cement, with significantly decreased rebound at site.

Abstract: The invention relates to a self-levelling fluid mortar including calcium sulphate, granulates, lime, water and either a silica and a compound containing alumina or a pozzuolana, and to a screed obtained from said fluid mortar. It also relates to the combined use of lime and either of a silica and of a compound containing alumina or a pozzuolana to increase the mechanical strength and reduce the water sensitivity of a screed.

Abstract: Cementation slurries well suited for encasing reinforcing elements therefor, for example prestressed steel cable, while reducing the risk of embrittlement thereof, contain from about 1.5% to 3% by weight of homogenizing and exudation-reducing hydrophilic particulates (e.g., precipitated silica particles) that are inert in respect of liquids, have a specific surface area of greater than about 200 m.sup.2 /g and which are fragmentable during mixing and/or injection into multiple fragments having particle sizes ranging from about 5 to 300 nanometers.

Abstract: Cementitious binders include calcium sulfate beta-hemihydrate, a cement component comprising Portland cement, and either silica fume or rice-husk ash. The silica fume or rice-husk ash component is at least about 92 wt % amorphous silica and has an alumina content of about 0.6 wt % or less.

Abstract: A shrinkage compensating cement exceeding the ASTM standard specification limiting 28 day expansion to 115% of the 7 day expansion. 28 day expansions of 120-200% are contemplated. The expansion takes place over an extended period of time, to better offset the shrinkage occurring as the concrete dries. The development of tensile stresses in the concrete is reduced and also is delayed, allowing more time for the tensile strength of the concrete to increase as the concrete dries. Shrinkage cracking is consequently significantly reduced.

Abstract: Cementation slurries well suited for encasing reinforcing elements therefor, for example prestressed steel cable, while reducing the risk of embrittlement thereof, contain from about 1.5% to 3% by weight of homogenizing and exudation-reducing hydrophilic particulates (e.g., precipitated silica particles) that are inert in respect of liquids, have a specific surface area of greater than about 200 m.sup.2 /g and which are fragmentable during mixing and/or injection into multiple fragments having particle sizes ranging from about 5 to 300 nanometers.

Abstract: A cementitious composition useful for water-resistant construction materials, including floor underlayments, backing boards, self-leveling floor materials, road patching materials, fiberboard, fire-proofing sprays, and fire-stopping materials includes about 20 wt. % to about 75 wt. % calcium sulfate beta-hemihydrate, about 10 wt. % to about 50 wt. % Portland cement, about 4 wt. % to about 20 wt. % silica fume and about 1 wt. % to about 50 wt. % pozzolanic aggregate. The Portland cement component may also be a blend of Portland cement with fly ash and/or ground blast slag.

Abstract: A dental gypsum bonded investment composition comprising 100 parts by weight of a mixture comprising (a) .alpha.-hemihydrate gypsum as a binder and (b) quartz and/or cristobalite as a refractory material, and optionally, (c) one or more aggregates selected from the group consisting of metallic oxides, metallic carbides, and metallic nitrides, which can substitute a part of the refractory material, having from 0.01 to 1.0 part by weight of a poly-tetrafluoroethylene resin and optionally, from 0.001 to 0.05 part by weight of one or more anionic surfactants selected from the group consisting of alkylbenzenesulfonates and alkylsulfates mixed therewith, is disclosed. The dental gypsum bonded investment composition of the invention keeps the fine particles to have a stable performance without being removed by the pneumatic transportation at the time of production, has superior heat resistance, and can be used for casting of alloys having a high melting point such as casting alloys for metalceramic restorations.

Abstract: A cementitious composition useful for water-resistant construction materials, including floor underlayments, backing boards, self-leveling floor materials, road patching materials, fiberboard, fire-proofing sprays, and fire-stopping materials includes about 20 wt. % to about 75 wt. % calcium sulfate beta-hemihydrate, about 10 wt. % to about 50 wt. % Portland cement, about 4 wt. % to about 20 wt. % silica fume and about 1 wt. % to about 50 wt. % pozzolanic aggregate. The Portland cement component may also be a blend of Portland cement with fly ash and/or ground blast slag.

Abstract: Compositions for low heat cements developed especially for massive concrete works and which exhibit a compressive strength/heat of hydration ratio of at least 7.0 at the age of 13 weeks. One of two inventions provides a powder prepared by mixing CaO, SiO.sub.2, and Al.sub.2 O.sub.3 materials, melting the mixture, quenching the melt, and grinding the quenched matter, the powder being composed mainly of amorphous substances and chemically having a CaO/SiO.sub.2 (molar ratio) of 0.8-1.5 and an Al.sub.2 O.sub.3 content of no more than 10 wt. %. The other invention provides a mixed powder comprising no less than 70 wt. % of a powder and no more than 30 wt. % of an addition (portland cement or the like), the powder being the same as that of the first invention in both predominance of amorphous substances and CaO/SiO.sub.2 (molar ratio) excepting the Al.sub.2 O.sub.3 content which is less than 12 wt. % in the second invention.

Abstract: Lightweight concrete products, useful for example in blocks, wall panels, floor and roof slabs, in which zeolite is a major component, its content in the cementing material of the products exceeding 50 wt. %. Depending on application, zeolite may be non-treated or calcined at a temperature enabling the surface activation of the zeolite and resulting high surface energy. Zeolite thus treated will work as both pozzolanic material and bubble-generating agent. Strengthening agents are used to improve compressive strength of the products. Also, a binding material, useful for hazardous waste stabilization, comprising zeolite as a major component, is proposed.

Abstract: A new and original water paint is disclosed, in liquid form, such as a milky emulsion, containing a low amount of water and comprising minerals, acetic acid solution, and other components. The new water paint has bactericidal, fireproof, transpiring, ecological, isolating and desalting properties and is suitable to coat manufactured building articles, wood, metals and plastic.

Abstract: A veneer plaster having strengths of substantially greater than 3,000 psi, abrasion resistance of penetrations less than 0.04 inch with 1,000 cycles of a five-pound brush using a 3M Granule Embedding Testing Machine, made from about 1,800 pounds of calcium sulfate beta hemihydrate, 200 pounds of fine silica sand, and about 4 pounds of a fine, white powder dispersant typified by a melamine-formaldehyde-sodium bisulfite polymer.

Abstract: The invention concerns a powdery, hydrophobic filler for bituminized traffic surfaces, including at least one substance that lowers the freezing point of water.

Abstract: Vibration damping thick-film coating composition comprising a coating composition comprising 100 parts by weight of a binder, from 20 to 200 parts by weight of a hydraulic inorganic filler, from 10 to 150 parts by weight of a filler other than the hydraulic inorganic filler, and from 10 to 7 parts by weight of (a) a cored filler or (b) a cored filler and a synthetic resin powder, and a method of forming the same.

Abstract: The invention relates to a gypsum-based cementitious composition capable of upon mixing with fine aggregate in a weight ratio to said gypsum-based cementitious composition of from about 1.25:1 to 2.5:1; and sufficient water to provide a pumpable, self-leveling wet gypsum-based cementitious composition having a flowability such that the wet gypsum-based cementitious composition completely self-levels to produce a topographically smooth surface without floating or finishing, providing, upon hardening, a sub-floor resistant to delamination from its substrate having a dust-free surface and compressive strength in the range of about 2500 to 6000 psi. The invention further relates to methods for making floor underlayments using these compositions, and for making the compositions.

Abstract: A concrete composition including a naturally-occurring, mineralogic silica source material as part of the binder. The silica source material may be, for example, feldspars, naturally-occurring zeolites, diatomaceous earths, clinoptilites, mordenites, chabozites, opaline silicas, novaculites, vitreous volcanic rocks (rhyolites, dacites, latites, andesites and their tuffs, and basalts), and high silica rocks (such as quartzite sands, sandstones and many igneous and metamorphic rocks such as. granites and schists), among others, having at least 50% by weight silica. The cementitious binder of the concrete composition may have a silica content of about 20-40% by weight from the mineralogic material. The compositions exhibit improved strength and endurance, including greater density and smoothness which imparts significantly improved surface characteristics to the material.

Abstract: A process for producing a hard material from a cementitious mixture, the process including the steps of blending together a cement constituent and a filler constituent whilst in a dry condition to provide a compactable homogeneous mixture containing a predetermined volume of voids defined between filler particles up to a predetermined size, laying the dry mixture onto a substrate, sparingly applying water to the surface of the mixture to dampen the surface layer of the mixture for causing setting of the cement in said surface layer and subsequently applying more water for causing setting and hardening of the remainder of the cement.