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: A composition for producing light plaster contains as main constitutive elements particles of plaster in anhydride or hemihydrate form and at least one foaming agent. The composition is characterized in that the foaming agent generates gas after a delay of 1 minute to 24 hours and constitutes 0.1 to 50% by weight of the total dry mixture. Also disclosed is the use of said composition to produce in-situ cellular plastic and low density plaster moldings.

Abstract: Starch-based microcellular foams composed of a solid matrix with a network of small open cells or pores are described. The foams have high pore volume, low density, and high surface area, and are prepared using a process wherein an aqueous gel prepared from gelatinized starch is treated to exchange the water in the gel with air while maintaining the integrity of the network of open cells or pores. The starch-based microcellular foams are particularly useful for encapsulation and later release of a substance.

Abstract: Pulp fibers derived from wood or non-wood plants or recycled paper products are individualized and dispersed in water, and mixed into cement-based mixtures using conventional mixing procedures at relatively low dosages of about 0.3-30 kg of fiber per cubic meter of concrete. Once individualized, the affinity of plant pulp fibers for water facilitates their dispersion in normal cement-based mixtures. Fresh cement-based materials incorporating the dispersed individualized plant pulp fibers provide desirable workability, resistance to segregation and bleeding, pumpability, finishability, and reduced rebound when pneumatically applied. Hardened cement-based materials incorporating the dispersed individualized plant pulp fibers provide improvements in crack resistance, toughness, impact resistance, fatigue life, abrasion resistance, and other mechanical, physical and durability characteristics.

Abstract: A lightweight insulating concrete is produced from a cement mix containing sawdust, diatomite, bentonite, and lime. The addition of rock salt and the entrainment of air bubbles results in a concrete with a high compressive strength, high thermal resistance (R) values (up to 30 to 40 times that of standard concrete), and excellent acoustical properties. The new insulating concrete is one third the weight of standard concrete. The composition is fire retardant, insect proof, and is very easy to clean up. Methods for producing cementitious materials include a process for manufacturing strong, lightweight, waterproof building products such as wall panels and roof panels. The mixture can be easily pumped for walls and floors. A well-insulated, cost-effective floor that has a slight give to it is excellent for gymnasium floors. This material is used for residential, light commercial, and agricultural buildings.

Abstract: The present invention is directed to concrete compositions prepared using firm aqueous gels (aquagels) as all or part of the aggregate in a concrete mix. The concrete sets around the aquagels in the initial set stage. Because the aquagels maintain the pore structure of the concrete while it sets, a concrete product can be obtained that has substantially uniform density regardless of depth. During the curing and/or drying stages, the moisture migrates out of the concrete and the aquagels, and the aquagels dry to a fraction of the size of the original aquagel in the cell or pore in the concrete. This results in cellular, lightweight concrete having reduced density, reduced weight, reduced thermal conductivity, and reduced sound transmission compared to concrete prepared without using aquagels.

Abstract: The invention provides a method of making gypsum products such as plasterboard from foamed gypsum plaster slurry. The method uses a first mixing chamber 10 containing a high speed rotor 14 and inlets 18, 19 for gypsum plaster and water. The initial dispersion of gypsum plaster and water foamed in the first chamber passes directly and continuously into a second chamber 25 containing a low speed rotor 29. Preformed foam is introduced into the second chamber through an inlet 33, and the foamed slurry product leaves the second chamber through an outlet 34, to be formed into plasterboard.

Abstract: This invention provides a hydraulic composition which contains a cementitious material in powder form, .beta.-1,3-glucan, and a superplasticizer. The composition makes it possible to prepare concrete with high resistance to segregation, high fluidity, and excellent filling ability. Because of this, vibration of the concrete is not necessary during casting; it can simply be poured.

Abstract: A hydraulic inorganic compositions which comprises a hydraulic inorganic powder at least one of polysaccharides selected from the group consisting of .beta.-1,3-glucans, pullulan and XCD-Polymer in an amount of 0.1-10 parts by weight in relation to 100 parts by weight of the hydraulic inorganic powder, and water in an effective amount.The composition preferably further contains a reinforcing fiber, a filler, in particular mountain leather, a coagulant and/or a second molding aid, in particular, methyl cellulose.The composition is hardened by hydration under normal pressure to provide a hardened molded article such as a cement board.

Abstract: A simple and inexpensive method of wetting a cement or gypsum-bonded fibrous mixture of building materials using water is characterized in that the water is added to the mixture of building materials at least partially in the form of a foam containing at least one foam forming surfactant and at least one foam stabilizer, or is added to the mixture of building materials in combination with at least one foam forming surfactant and at least one foam stabilizer prior to foam formation, and then at least partially foamed in situ, such that a sufficient quantity of water is present in the mixture to provide a final mixture exhibiting a powdery-crumbly consistency.