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.

Abstract: A concrete composition having a 28-day design compressive strength of 4000 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 375 pounds per cubic yard hydraulic cement (e.g., Portland cement), about 113 pounds per cubic yard pozzolanic material (e.g., Type C fly ash), about 1735 pounds per cubic yard fine aggregate (e.g., FA-2 sand), about 1434 pounds per cubic yard coarse aggregate (e.g., CA-li 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: A concrete composition having a 28-day design compressive strength of 4000 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 375 pounds per cubic yard hydraulic cement (e.g., Portland cement), about 113 pounds per cubic yard pozzolanic material (e.g., Type C fly ash), about 1735 pounds per cubic yard fine aggregate (e.g., FA-2 sand), about 1434 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: 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: 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.

Abstract: Design optimization methods can be used to design concrete mixtures having optimized properties, including desired strength and slump at minimal cost. The design optimization methods use a computer-implemented process that is able to design and virtually “test” millions of hypothetical concrete compositions using mathematical algorithms that interrelate a number of variables that affect strength, slump, cost and other desired features. The design optimization procedure utilizes a constant K (or K factor) within Feret's strength equation that varies (e.g., logarithmically) with concrete strength for any given set of raw material inputs and processing equipment. That means that the binding efficiency or effectiveness of hydraulic cement increases with increasing concentration so long as the concrete remains optimized. The knowledge of how the K factor varies with binding efficiency and strength is a powerful tool that can be applied in multiple circumstances.