| 摘要 |
<p>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 366 pounds per cubic yard hydraulic cement (e.g., Portland cement), about 110 pounds per cubic yard pozzolanic material (e.g., Type C fly ash), about 1654 pounds per cubic yard fine aggregate (e.g., FA-2 sand), about 1367 pounds per cubic yard coarse aggregate (e.g., CA-11 state rock, 3/4 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.</p> |
