Abstract:
A concrete composition having a 28-day design compressive strength of 3000 psi and a slump of about 5 inches is optimized to have high workability and a high strength to cement ratio. The concrete composition contains about 299 pounds per cubic yard hydraulic cement (e.g., Portland cement), about 90 pounds per cubic yard pozzolanic material (e.g., Type C fly ash), about 1697 pounds per cubic yard fine aggregate (e.g., FA-2 sand), about 1403 pounds per cubic yard coarse aggregate (e.g., CA-11 state rock, ¾ inch), about 269 pounds per cubic yard water (e.g., potable water), and about 1.4 fluid ounces of air entraining agent per cwt of hydraulic cement. Workability and strength to cement ratio were increased compared to one or more preexisting concrete compositions having the same 28-day design compressive strength and similar slump by optimizing the ratio of fine aggregate to coarse aggregate. The concrete composition is further characterized by high cohesiveness, resulting in relatively little or no segregation or bleeding.
Abstract:
Concrete compositions have a fine-to-coarse aggregate ratio optimized for increased workability with minimal segregation and bleeding. The concrete compositions include at least water, cement, coarse aggregate, and fine aggregate and have a slump of at least 1 inch and a 28-day compressive strength of at least about 1500 psi. Workability is improved by minimizing the viscosity as a function of the aggregate content, while minimizing segregation and bleeding. To improve workability, the concrete compositions include between 45% and 65% fine aggregate and between 35% and 55% coarse aggregate as a function of total aggregate volume. For relatively low strength concrete (1500-4500 psi), the fine aggregate is 55-65% of the total aggregate volume. For medium strength concrete (4500-8000 psi), the fine aggregate is 50-60% of the total aggregate volume. For high strength concrete (>8000 psi), the fine aggregate is 45-55% of the total aggregate volume. Overall workability can be maintained or improved even if slump is decreased.
Abstract:
Compositions and methods for manufacturing sheets having a starch-bound matrix reinforced with fibers and optionally including an inorganic mineral filler. Suitable mixtures for forming the sheets are prepared by mixing together water, unmodified and ungelatinized starch granules, an auxiliary water-dispersible organic polymer, fibers, and optionally an inorganic mineral filler in the correct proportions to form a sheet having desired properties. The mixtures are formed into sheets by passing them between one or more sets of heated rollers to form green sheets. The heated rollers cause the auxiliary polymer to form a skin on the outer surfaces of the sheet that prevents the starch granules from causing the sheet to adhere to the rollers upon gelation of the starch. The green sheets are passed between heated rollers to gelatinize the starch granules, and then to dry the sheet by removing a substantial portion of the water by evaporation. The starch and auxiliary polymer form the binding matrix of the sheets with the fibers and optional inorganic filler dispersed throughout the binding matrix. The starch-bound sheets can be cut, rolled, pressed, scored, perforated, folded, and glued to fashion articles from the sheets much like paper or paperboard. The sheets are particularly useful in the mass production of containers, such as food and beverage containers.
Abstract:
Compositions, methods, and systems for manufacturing articles, particularlycontainers and packaging materials, having a particle packed, highly inorganically filled, cellular matrix are disclosed. Suitable inorganically filled mixtures are prepared by mixing together a starch-based binder, a solvent, inorganic aggregates, and optimal admixtures, e.g., fibers, mold-releasing agents, rheology-modifying agents, plasticizers, coating materials, and dispersants, in the correct proportions to form an article which has the desired performance criteria. The inorganically filled mixtures have a predetermined viscosity and are heated between molds at an elevated temperature and pressure to produce form-stable articles having a desired shape and a selectively controlled cellular, structural matrix. The molded articles may be placed in a high humidity chamber to obtain the necessary flexibility for their intended use. The articles may be manufactured to have properties substantially similar to articles presently made from conventional materials like paper, paperboard, polystyrene, plastic, or other organic materials. They have especial utility in the mass-production of containers, particularly food and beverage containers.
Abstract:
Compositions, methods, and systems for manufacturing articles, particularly containers and packaging materials, having a particle packed, highly inorganically filled, cellular matrix are disclosed. Suitable inorganically filled mixtures are prepared by mixing together a starch-based binder, a solvent, inorganic aggregates, and optimal admixtures, e.g., fibers, mold-releasing agents, rheology-modifying agents, plasticizers, coating materials, and dispersants, in the correct proportions to form an article which has the desired performance criteria. The inorganically filled mixtures have a predetermined viscosity and are heated between molds at an elevated temperature and pressure to produce form-stable articles having a desired shape and a selectively controlled cellular, structure matrix. The molded articles may be placed in a high humidity chamber to obtain the necessary flexibility for their intended use. The articles may be manufactured to have properties substantially similar to articles presently made from conventional materials like paper, paperboard, polystyrene, plastic, or other organic materials. They have especial utility in the mass-production of containers, particularly food and beverage containers.
Abstract:
Compositions, methods, and systems for manufacturing articles, particularly containers and packaging materials, having a highly inorganically filled matrix. Suitable inorganically filled mixtures are prepared by mixing together an organic polymer binder, water, one or more aggregate materials, fibers, and optional admixtures in the correct proportions in order to form an article which has the desired performance criteria. The inorganically filled mixtures are molded to fashion a portion of the mixture into a form stable shape for the desired article. Once the article has obtained form stability, the article is removed from the mold and allowed to harden to gain strength. The articles may have properties substantially similar to articles presently made from traditional materials like paper, paperboard, polystyrene, plastic, or metal. They have especial utility in the mass production of containers, particularly food and beverage containers.
Abstract:
Compositions, methods, and systems for manufacturing articles, particularly containers and packaging materials, having a fiber-reinforced, starch-bound cellular matrix. Suitable mixtures used to form the articles are prepared by first preparing a viscous preblended mixture comprising water, a gelatinized starch-based binder, and fibers having an average length greater than about 2 mm. The highly viscous preblended mixture effectively transfers the shearing forces of the mixer to the fibers. The final moldable mixture is then prepared by mixing into the preblended mixture the remaining starch-based binder, water, and other desired admixtures, e.g., mold-releasing agents, inorganic filler rheology-modifying agents, plasticizers, coating materials, and dispersants, in the correct proportions to form an article which has the desired performance criteria. The moldable mixtures are heated between molds at an elevated temperature and pressure to produce form-stable articles having a desired shape and a selectively controlled foamed structural matrix. The articles may be manufactured to have properties substantially similar to articles presently made from conventional materials like paper, paperboard, polystyrene, plastic, or other organic-based materials and have especial utility in the mass-production of containers, particularly food and beverage containers.
Abstract:
Concrete compositions have a fine-to-coarse aggregate ratio optimized for decreased viscosity and increased workability. The concrete compositions include at least water, cement, coarse aggregate, and fine aggregate and have a slump of at least 1 inch and a 28-day compressive strength of at least about 1500 psi. Workability is improved by minimizing the viscosity as a function of the aggregate content. To improve workability, the concrete compositions include between 45% and 65% fine aggregate and between 35% and 55% coarse aggregate as a function of total aggregate volume. For relatively low strength concrete (1500-4500 psi), the fine aggregate is 55-65% of the total aggregate volume. For medium strength concrete (4500-8000 psi), the fine aggregate is 50-60% of the total aggregate volume. For high strength concrete (>8000 psi), the fine aggregate is 45-55% of the total aggregate volume. Overall workability can be maintained or improved even if slump is decreased.
Abstract:
A concrete composition having a 28-day design compressive strength of 3000 psi and a slump of about 5 inches is optimized to have high workability and a high strength to cement ratio. The concrete composition contains about 340 pounds per cubic yard hydraulic cement (e.g. Portland cement), about 102 pounds per cubic yard pozzolanic material (e.g., Type C fly ash), about 1757 pounds per cubic yard fine aggregate (e.g., FA-2 sand), about 1452 pounds per cubic yard coarse aggregate (e.g., CA-11 state rock, ¾ inch), and about 294 pounds per cubic yard water (e.g., potable water). Workability and strength to cement ratio were increased compared to one or more preexisting concrete compositions having the same 28-day design compressive strength and similar slump by optimizing the ratio of fine aggregate to coarse aggregate. The concrete composition is further characterized by high cohesiveness, resulting in relatively little or no segregation or bleeding.
Abstract:
Concrete compositions have a fine-to-coarse particulates ratio optimized for decreased viscosity and increased workability. The concrete compositions include at least water, cement, coarse aggregate, and fine aggregate and have a slump of at least 1 inch and a 28-day compressive strength of at least about 1500 psi. Workability is improved by minimizing the viscosity as a function of the particulates ratio. To improve workability, the concrete compositions include between 49-85% fine particulates (e.g., cement and fine aggregate) and between 15-51% coarse particulates as a percentage of overall particulates volume. For normal strength concrete (up to about 8500 psi, or 58.6 MPa), the fine particulates fraction comprises about 50-75% by volume of total particulates. For high strength concrete (>8500 psi, or 58.6 MPa), the fine particulates fraction comprises about 56-85% by volume of total particulates. Overall workability can be maintained or improved even if slump is decreased.